configs/axoloti: Adds initial support for the Axoloti sound/music synthesizer board. Board is based on STM32F427 SoC. See http://www.axoloti.com/.

2019-06-02 12:38:41 -06:00 · 2019-06-02 12:38:41 -06:00 · 6a98b2825e
commit 6a98b2825e
parent 2357446491
25 changed files with 2990 additions and 0 deletions
--- a/Documentation/README.html
+++ b/Documentation/README.html
@ -63,6 +63,8 @@ nuttx/
 |   |   `- <a href="https://bitbucket.org/nuttx/nuttx/src/master/configs/arduino-due/README.txt" target="_blank"><b><i>README.txt</i></b></a>
 |   |- avr32dev1/
 |   |   `- <a href="https://bitbucket.org/nuttx/nuttx/src/master/configs/avr32dev1/README.txt" target="_blank"><b><i>README.txt</i></b></a>
+ |   |- axoloti/
+ |   |   `- <a href="https://bitbucket.org/nuttx/nuttx/src/master/configs/axoloti/README.txt" target="_blank"><b><i>README.txt</i></b></a>
 |   |- b-l475e-iot01a/
 |   |   `- <a href="https://bitbucket.org/nuttx/nuttx/src/master/configs/b-l475e-iot01a/README.txt" target="_blank"><b><i>README.txt</i></b></a>
 |   |- bambino-200e/
--- a/README.txt
+++ b/README.txt
@ -1738,6 +1738,8 @@ nuttx/
 |   |   `- README.txt
 |   |- avr32dev1/
 |   |   `- README.txt
+ |   |- axoloti/
+ |   |   `- README.txt
 |   |- b-l475e-iot01a/
 |   |   `- README.txt
 |   |- bambino-200e/
--- a/configs/Kconfig
+++ b/configs/Kconfig
@ -49,6 +49,16 @@ config ARCH_BOARD_AVR32DEV1
 		Atmel website.  STATUS: This port is functional but very basic.  There
 		are configurations for NSH and the OS test.

+config ARCH_BOARD_AXOLOTI
+	bool "Axoloti board"
+	depends on ARCH_CHIP_STM32F427I
+	select ARCH_HAVE_LEDS
+	select ARCH_HAVE_BUTTONS
+	select ARCH_HAVE_IRQBUTTONS
+	---help---
+		Axoloti synthesizer board based on the STMicro STM32F427IGH6 MCU.
+		See: http://www.axoloti.com/
+
 config ARCH_BOARD_C5471EVM
 	bool "Spectrum Digital C5471 evaluation board"
 	depends on ARCH_CHIP_C5471
@ -1814,6 +1824,7 @@ config ARCH_BOARD
 	default "arduino-mega2560"         if ARCH_BOARD_ARDUINO_MEGA2560
 	default "arduino-due"              if ARCH_BOARD_ARDUINO_DUE
 	default "avr32dev1"                if ARCH_BOARD_AVR32DEV1
+	default "axoloti"                  if ARCH_BOARD_AXOLOTI
 	default "bambino-200e"             if ARCH_BOARD_BAMBINO_200E
 	default "c5471evm"                 if ARCH_BOARD_C5471EVM
 	default "clicker2-stm32"           if ARCH_BOARD_CLICKER2_STM32
--- a/configs/README.txt
+++ b/configs/README.txt
@ -183,6 +183,10 @@ configs/avr32dev1
  Atmel website.  STATUS: This port is functional but very basic.  There
  are configurations for NSH and the OS test.

+configs/axoloti
+  Support for the Axoloti synthesizer board based on the STMicro
+  STM32F427IGH6 MCU.  See: http://www.axoloti.com/
+
 configs/b-l072z-lrwan1
  STMicro STM32L0 Discovery kit with LoRa/SigFox based on STM32L072CZ MCU.

--- a/configs/axoloti/Kconfig
+++ b/configs/axoloti/Kconfig
@ -0,0 +1,8 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+if ARCH_BOARD_AXOLOTI
+
+endif
--- a/configs/axoloti/README.txt
+++ b/configs/axoloti/README.txt
@ -0,0 +1,20 @@
+README
+======
+
+This README discusses issues unique to NuttX configurations for the
+Axoloti open source synthesizer board featuring the STM32F427IGH6
+MCU. The STM32F427IGH6 has a 180MHz Cortex-M4 core with 1MiB Flash
+memory and 256KiB of SRAM. The board features:
+
+  - ADAU1961 24-bit 96 kHz stereo CODEC
+  - 1/4" in/out jacks for analog audio signals
+  - 3.5 mm jack for analog audio signals
+  - 8 MiB of SDRAM (Alliance Memory AS4C4M16SA)
+  - Serial MIDI in/out ports
+  - SD Card slot
+  - Two user LEDs and one (GPIO) push-button
+  - USB OTG FS with Micro-AB connector (USB device mode operation)
+  - USB OTG HS with Type-A connector (USB host mode operation)
+  - Easy access to most IO pins
+
+Refer to http://www.axoloti.com/ for further information about this board.
--- a/configs/axoloti/include/board.h
+++ b/configs/axoloti/include/board.h
@ -0,0 +1,275 @@
+/************************************************************************************
+ * configs/axoloti/include/board.h
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************/
+
+#ifndef __CONFIGS_AXOLOTI_INCLUDE_BOARD_H
+#define __CONFIGS_AXOLOTI_INCLUDE_BOARD_H
+
+/************************************************************************************
+ * Included Files
+ ************************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifndef __ASSEMBLY__
+#  include <stdint.h>
+#  include <stdbool.h>
+#endif
+
+/************************************************************************************
+ * Pre-processor Definitions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Clocking
+ * The Axoloti board has an external 8MHz crystal.
+ * The SoC can run at 180MHz, but the required USB clock of 48MHz cannot be
+ * configured at that system clock rate, so the core clock is 168MHz.
+ *
+ * This is the canonical configuration:
+ *   System Clock source           : PLL (HSE)
+ *   SYSCLK(Hz)                    : 168000000    Determined by PLL configuration
+ *   HCLK(Hz)                      : 168000000    (STM32_RCC_CFGR_HPRE)
+ *   AHB Prescaler                 : 1            (STM32_RCC_CFGR_HPRE)
+ *   APB1 Prescaler                : 4            (STM32_RCC_CFGR_PPRE1)
+ *   APB2 Prescaler                : 2            (STM32_RCC_CFGR_PPRE2)
+ *   HSE Frequency(Hz)             : 8000000      (STM32_BOARD_XTAL)
+ *   PLLM                          : 8            (STM32_PLLCFG_PLLM)
+ *   PLLN                          : 336          (STM32_PLLCFG_PLLN)
+ *   PLLP                          : 2            (STM32_PLLCFG_PLLP)
+ *   PLLQ                          : 7            (STM32_PLLCFG_PLLQ)
+ *   Main regulator output voltage : Scale1 mode  Needed for high speed SYSCLK
+ *   Flash Latency(WS)             : 5
+ *   Prefetch Buffer               : OFF
+ *   Instruction cache             : ON
+ *   Data cache                    : ON
+ *   Require 48MHz for USB OTG FS, : Enabled
+ *   SDIO and RNG clock
+ */
+
+/* HSI - 16 MHz RC factory-trimmed
+ * LSI - 32 KHz RC
+ * HSE - On-board crystal frequency is 8MHz
+ * LSE - 32.768 kHz
+ */
+
+#define STM32_BOARD_XTAL        8000000ul
+
+#define STM32_HSI_FREQUENCY     16000000ul
+#define STM32_LSI_FREQUENCY     32000
+#define STM32_HSE_FREQUENCY     STM32_BOARD_XTAL
+#define STM32_LSE_FREQUENCY     32768
+
+/* Main PLL Configuration.
+ *
+ * PLL source is HSE
+ * PLL_VCO = (STM32_HSE_FREQUENCY / PLLM) * PLLN
+ *         = (8,000,000 / 8) * 336
+ *         = 336,000,000
+ * SYSCLK  = PLL_VCO / PLLP
+ *         = 336,000,000 / 2 = 168,000,000
+ * USB OTG FS, SDIO and RNG Clock
+ *         =  PLL_VCO / PLLQ
+ *         = 48,000,000
+ */
+
+#define STM32_PLLCFG_PLLM       RCC_PLLCFG_PLLM(8)
+#define STM32_PLLCFG_PLLN       RCC_PLLCFG_PLLN(336)
+#define STM32_PLLCFG_PLLP       RCC_PLLCFG_PLLP_2
+#define STM32_PLLCFG_PLLQ       RCC_PLLCFG_PLLQ(7)
+
+#define STM32_SYSCLK_FREQUENCY  168000000ul
+
+/* AHB clock (HCLK) is SYSCLK (168MHz) */
+
+#define STM32_RCC_CFGR_HPRE     RCC_CFGR_HPRE_SYSCLK    /* HCLK  = SYSCLK / 1 */
+#define STM32_HCLK_FREQUENCY    STM32_SYSCLK_FREQUENCY
+#define STM32_BOARD_HCLK        STM32_HCLK_FREQUENCY    /* same as above, to satisfy compiler */
+
+/* APB1 clock (PCLK1) is HCLK/4 (42MHz) */
+
+#define STM32_RCC_CFGR_PPRE1    RCC_CFGR_PPRE1_HCLKd4   /* PCLK1 = HCLK / 4 */
+#define STM32_PCLK1_FREQUENCY   (STM32_HCLK_FREQUENCY/4)
+
+/* APB2 clock (PCLK2) is HCLK/2 (84MHz) */
+
+#define STM32_RCC_CFGR_PPRE2    RCC_CFGR_PPRE2_HCLKd2   /* PCLK2 = HCLK / 2 */
+#define STM32_PCLK2_FREQUENCY   (STM32_HCLK_FREQUENCY/2)
+
+/************************************************************************************
+ * LED Definitions
+ * If CONFIG_ARCH_LEDS is not defined, then the user can control the LEDs in any
+ * way.  The following definitions are used to access individual LEDs.
+ */
+
+/* LED index values for use with board_userled() */
+
+#define BOARD_LED1        0
+#define BOARD_LED2        1
+#define BOARD_NLEDS       2
+#define BOARD_LED_GREEN   BOARD_LED1
+#define BOARD_LED_RED     BOARD_LED2
+
+/* LED bits for use with board_userled_all() */
+
+#define BOARD_LED1_BIT    (1 << BOARD_LED1)
+#define BOARD_LED2_BIT    (1 << BOARD_LED2)
+
+/************************************************************************************
+ * Button Definitions
+ * There are two buttons on the axoloti, one of them is GPIO connected. The other
+ * is a reset button and is not under software control.
+ */
+
+#define BUTTON_USER        0
+#define NUM_BUTTONS        1
+#define BUTTON_USER_BIT    (1 << BUTTON_USER)
+
+/************************************************************************************
+ * UARTs
+ * The MIDI in/out ports of the axoloti are connected on USART6.
+ * It maybe convenient to run a serial port connected to the header pins,
+ * so we can optionally use USART1 for that.
+ */
+
+/* USART1 - console on header pins */
+
+#define GPIO_USART1_RX GPIO_USART1_RX_2 /* AF7, PB7 */
+#define GPIO_USART1_TX GPIO_USART1_TX_2 /* AF7, PB6 */
+
+/* USART6 - midi in/out */
+
+#define GPIO_USART6_RX (GPIO_ALT|GPIO_AF8|GPIO_PORTG|GPIO_PIN9| \
+                        GPIO_PULLUP|GPIO_SPEED_2MHz|GPIO_PUSHPULL)
+
+#define GPIO_USART6_TX (GPIO_ALT|GPIO_AF8|GPIO_PORTG|GPIO_PIN14| \
+                        GPIO_FLOAT|GPIO_SPEED_2MHz|GPIO_OPENDRAIN)
+
+/************************************************************************************
+ * I2C Bus
+ * Turn on the internal pullups since there are no external pullups.
+ */
+
+/* I2C1 - for external devices */
+
+#define GPIO_I2C1_SCL (GPIO_ALT|GPIO_AF4|GPIO_PORTB|GPIO_PIN8| \
+                       GPIO_SPEED_2MHz|GPIO_OPENDRAIN|GPIO_PULLUP)
+
+#define GPIO_I2C1_SDA  (GPIO_ALT|GPIO_AF4|GPIO_PORTB|GPIO_PIN9| \
+                       GPIO_SPEED_2MHz|GPIO_OPENDRAIN|GPIO_PULLUP)
+
+/* I2C3 - for the ADAU1961 codec */
+
+#define GPIO_I2C3_SCL (GPIO_ALT|GPIO_AF4|GPIO_PORTH|GPIO_PIN7| \
+                       GPIO_SPEED_2MHz|GPIO_OPENDRAIN|GPIO_PULLUP)
+
+#define GPIO_I2C3_SDA (GPIO_ALT|GPIO_AF4|GPIO_PORTH|GPIO_PIN8| \
+                       GPIO_SPEED_2MHz|GPIO_OPENDRAIN|GPIO_PULLUP)
+
+/************************************************************************************
+ * SAI Bus
+ * Used with the ADAU1961 CODEC
+ * PE3_SAI1_SD_B (GPIO_SAI1_SD_B_1)
+ * PE4_SAI1_FS_A (GPIO_SAI1_FS_A)
+ * PE5_SAI1_SCK_A (GPIO_SAI1_SCK_A)
+ * PE6_SAI1_SD_A (GPIO_SAI1_SD_A_2)
+ * PA8_MCO1
+ */
+
+#define GPIO_SAI1_SD_B GPIO_SAI1_SD_B_1 /* AF6, PE3 */
+#define GPIO_SAI1_SD_A GPIO_SAI1_SD_A_2 /* AF6, PE6 */
+
+#define STM32_SAI1_FREQUENCY (48000 * 2 * 256)  /* TODO ?? */
+
+/* DAC DMA to Codec
+ * dma 2, stream 1, channel 0
+ * memory to peripheral
+ * 32 bits
+ */
+#define DMACHAN_SAI1_A DMAMAP_SAI1_A_1
+
+/* ADC DMA from Codec
+ * dma 2, stream 4, channel 1,
+ * peripheral to memory
+ * 32 bits
+ */
+#define DMACHAN_SAI1_B DMAMAP_SAI1_B_2
+
+/************************************************************************************
+ * SDIO
+ * Used for the SD card interface.
+ * d0 (AF12, PC8)
+ * d1 (AF12, PC9)
+ * d2 (AF12, PC10)
+ * d3 (AF12, PC11)
+ * clk (AF12, PC12)
+ * cmd (AF12, PD2)
+ * cd1 PD13
+ */
+
+/* SDIO dividers. Note that slower clocking is required when DMA is disabled
+ * in order to avoid RX overrun/TX underrun errors due to delayed responses
+ * to service FIFOs in interrupt driven mode.  These values have not been
+ * tuned!!!
+ *
+ * SDIOCLK=48MHz, SDIO_CK=SDIOCLK/(118+2)=400 KHz
+ */
+
+#define SDIO_INIT_CLKDIV (118 << SDIO_CLKCR_CLKDIV_SHIFT)
+
+/* DMA ON:  SDIOCLK=48MHz, SDIO_CK=SDIOCLK/(1+2)=16 MHz
+ * DMA OFF: SDIOCLK=48MHz, SDIO_CK=SDIOCLK/(2+2)=12 MHz
+ */
+
+#ifdef CONFIG_SDIO_DMA
+#  define SDIO_MMCXFR_CLKDIV (1 << SDIO_CLKCR_CLKDIV_SHIFT)
+#else
+#  define SDIO_MMCXFR_CLKDIV (2 << SDIO_CLKCR_CLKDIV_SHIFT)
+#endif
+
+/* DMA ON:  SDIOCLK=48MHz, SDIO_CK=SDIOCLK/(1+2)=16 MHz
+ * DMA OFF: SDIOCLK=48MHz, SDIO_CK=SDIOCLK/(2+2)=12 MHz
+ */
+
+#ifdef CONFIG_SDIO_DMA
+#  define SDIO_SDXFR_CLKDIV (1 << SDIO_CLKCR_CLKDIV_SHIFT)
+#else
+#  define SDIO_SDXFR_CLKDIV (2 << SDIO_CLKCR_CLKDIV_SHIFT)
+#endif
+
+/* dma 2, stream 6, channel 4 */
+
+#define DMAMAP_SDIO DMAMAP_SDIO_2
+
+#endif /* __CONFIG_AXOLOTI_INCLUDE_BOARD_H */
--- a/configs/axoloti/nsh/defconfig
+++ b/configs/axoloti/nsh/defconfig
@ -0,0 +1,41 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+# CONFIG_ARCH_FPU is not set
+# CONFIG_ARCH_LEDS is not set
+# CONFIG_NSH_DISABLE_PRINTF is not set
+# CONFIG_NSH_DISABLE_PS is not set
+# CONFIG_STANDARD_SERIAL is not set
+CONFIG_ARCH="arm"
+CONFIG_ARCH_BOARD="axoloti"
+CONFIG_ARCH_BOARD_AXOLOTI=y
+CONFIG_ARCH_BUTTONS=y
+CONFIG_ARCH_CHIP_STM32=y
+CONFIG_ARCH_CHIP_STM32F427I=y
+CONFIG_ARCH_IRQBUTTONS=y
+CONFIG_BOARD_LATE_INITIALIZE=y
+CONFIG_BOARD_LOOPSPERMSEC=16717
+CONFIG_BUTTONS=y
+CONFIG_BUTTONS_LOWER=y
+CONFIG_CLOCK_MONOTONIC=y
+CONFIG_INPUT=y
+CONFIG_LIBC_FLOATINGPOINT=y
+CONFIG_MM_REGIONS=2
+CONFIG_RAW_BINARY=y
+CONFIG_STM32_CCMEXCLUDE=y
+CONFIG_STM32_DISABLE_IDLE_SLEEP_DURING_DEBUG=y
+CONFIG_STM32_JTAG_FULL_ENABLE=y
+CONFIG_STM32_USART1=y
+CONFIG_STM32_USART6=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_USART1_SERIAL_CONSOLE=y
+CONFIG_USART6_BAUD=31250
+CONFIG_USART6_RXBUFSIZE=128
+CONFIG_USART6_TXBUFSIZE=32
+CONFIG_USERLED=y
+CONFIG_USERLED_LOWER=y
+CONFIG_USER_ENTRYPOINT="nsh_main"
--- a/configs/axoloti/scripts/Make.defs
+++ b/configs/axoloti/scripts/Make.defs
@ -0,0 +1,138 @@
+############################################################################
+# configs/axoloti/scripts/Make.defs
+#
+#   Copyright (C) 2011-2012, 2016-2017 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name NuttX nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+include ${TOPDIR}/.config
+include ${TOPDIR}/tools/Config.mk
+include ${TOPDIR}/arch/arm/src/armv7-m/Toolchain.defs
+
+LDSCRIPT = ld.script
+
+ifeq ($(WINTOOL),y)
+  # Windows-native toolchains
+  DIRLINK = $(TOPDIR)/tools/copydir.sh
+  DIRUNLINK = $(TOPDIR)/tools/unlink.sh
+  MKDEP = $(TOPDIR)/tools/mkwindeps.sh
+  ARCHINCLUDES = -I. -isystem "${shell cygpath -w $(TOPDIR)/include}"
+  ARCHXXINCLUDES = -I. -isystem "${shell cygpath -w $(TOPDIR)/include}" -isystem "${shell cygpath -w $(TOPDIR)/include/cxx}"
+  ARCHSCRIPT = -T "${shell cygpath -w $(TOPDIR)/configs/$(CONFIG_ARCH_BOARD)/scripts/$(LDSCRIPT)}"
+else
+  # Linux/Cygwin-native toolchain
+  MKDEP = $(TOPDIR)/tools/mkdeps$(HOSTEXEEXT)
+  ARCHINCLUDES = -I. -isystem $(TOPDIR)/include
+  ARCHXXINCLUDES = -I. -isystem $(TOPDIR)/include -isystem $(TOPDIR)/include/cxx
+  ARCHSCRIPT = -T$(TOPDIR)/configs/$(CONFIG_ARCH_BOARD)/scripts/$(LDSCRIPT)
+endif
+
+CC = $(CROSSDEV)gcc
+CXX = $(CROSSDEV)g++
+CPP = $(CROSSDEV)gcc -E
+LD = $(CROSSDEV)ld
+STRIP = $(CROSSDEV)strip --strip-unneeded
+AR = $(ARCROSSDEV)ar rcs
+NM = $(ARCROSSDEV)nm
+OBJCOPY = $(CROSSDEV)objcopy
+OBJDUMP = $(CROSSDEV)objdump
+
+ARCHCCVERSION = ${shell $(CC) -v 2>&1 | sed -n '/^gcc version/p' | sed -e 's/^gcc version \([0-9\.]\)/\1/g' -e 's/[-\ ].*//g' -e '1q'}
+ARCHCCMAJOR = ${shell echo $(ARCHCCVERSION) | cut -d'.' -f1}
+
+ifeq ($(CONFIG_DEBUG_SYMBOLS),y)
+  ARCHOPTIMIZATION = -g
+endif
+
+ifneq ($(CONFIG_DEBUG_NOOPT),y)
+  ARCHOPTIMIZATION += $(MAXOPTIMIZATION) -fno-strict-aliasing -fno-strength-reduce -fomit-frame-pointer
+endif
+
+ARCHCFLAGS = -fno-builtin
+ARCHCXXFLAGS = -fno-builtin -fno-exceptions -fcheck-new -fno-rtti
+ARCHWARNINGS = -Wall -Wstrict-prototypes -Wshadow -Wundef
+ARCHWARNINGSXX = -Wall -Wshadow -Wundef
+ARCHDEFINES =
+ARCHPICFLAGS = -fpic -msingle-pic-base -mpic-register=r10
+
+CFLAGS = $(ARCHCFLAGS) $(ARCHWARNINGS) $(ARCHOPTIMIZATION) $(ARCHCPUFLAGS) $(ARCHINCLUDES) $(ARCHDEFINES) $(EXTRADEFINES) -pipe
+CPICFLAGS = $(ARCHPICFLAGS) $(CFLAGS)
+CXXFLAGS = $(ARCHCXXFLAGS) $(ARCHWARNINGSXX) $(ARCHOPTIMIZATION) $(ARCHCPUFLAGS) $(ARCHXXINCLUDES) $(ARCHDEFINES) $(EXTRADEFINES) -pipe
+CXXPICFLAGS = $(ARCHPICFLAGS) $(CXXFLAGS)
+CPPFLAGS = $(ARCHINCLUDES) $(ARCHDEFINES) $(EXTRADEFINES)
+AFLAGS = $(CFLAGS) -D__ASSEMBLY__
+
+NXFLATLDFLAGS1 = -r -d -warn-common
+NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-pcrel.ld -no-check-sections
+LDNXFLATFLAGS = -e main -s 2048
+
+# Loadable module definitions
+
+CMODULEFLAGS = $(CFLAGS) -mlong-calls # --target1-abs
+
+LDMODULEFLAGS = -r -e module_initialize
+ifeq ($(WINTOOL),y)
+  LDMODULEFLAGS += -T "${shell cygpath -w $(TOPDIR)/libs/libc/modlib/gnu-elf.ld}"
+else
+  LDMODULEFLAGS += -T $(TOPDIR)/libs/libc/modlib/gnu-elf.ld
+endif
+
+# ELF module definitions
+
+CELFFLAGS = $(CFLAGS) -mlong-calls # --target1-abs
+CXXELFFLAGS = $(CXXFLAGS) -mlong-calls # --target1-abs
+
+LDELFFLAGS = -r -e main
+ifeq ($(WINTOOL),y)
+  LDELFFLAGS += -T "${shell cygpath -w $(TOPDIR)/configs/$(CONFIG_ARCH_BOARD)/scripts/gnu-elf.ld}"
+else
+  LDELFFLAGS += -T $(TOPDIR)/configs/$(CONFIG_ARCH_BOARD)/scripts/gnu-elf.ld
+endif
+
+
+ASMEXT = .S
+OBJEXT = .o
+LIBEXT = .a
+EXEEXT =
+
+ifneq ($(CROSSDEV),arm-nuttx-elf-)
+  LDFLAGS += -nostartfiles -nodefaultlibs
+endif
+ifeq ($(CONFIG_DEBUG_SYMBOLS),y)
+  LDFLAGS += -g
+endif
+
+
+HOSTCC = gcc
+HOSTINCLUDES = -I.
+HOSTCFLAGS = -Wall -Wstrict-prototypes -Wshadow -Wundef -g -pipe
+HOSTLDFLAGS =
+
--- a/configs/axoloti/scripts/gnu-elf.ld
+++ b/configs/axoloti/scripts/gnu-elf.ld
@ -0,0 +1,139 @@
+/****************************************************************************
+ * configs/axoloti/scripts/gnu-elf.ld
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+SECTIONS
+{
+  .text 0x00000000 :
+    {
+      _stext = . ;
+      *(.text)
+      *(.text.*)
+      *(.gnu.warning)
+      *(.stub)
+      *(.glue_7)
+      *(.glue_7t)
+      *(.jcr)
+
+      /* C++ support:  The .init and .fini sections contain specific logic
+       * to manage static constructors and destructors.
+       */
+
+      *(.gnu.linkonce.t.*)
+      *(.init)             /* Old ABI */
+      *(.fini)             /* Old ABI */
+      _etext = . ;
+    }
+
+  .ARM.extab :
+    {
+      *(.ARM.extab*)
+    }
+
+  .ARM.exidx :
+    {
+      *(.ARM.exidx*)
+    }
+
+  .rodata :
+    {
+      _srodata = . ;
+      *(.rodata)
+      *(.rodata1)
+      *(.rodata.*)
+      *(.gnu.linkonce.r*)
+      _erodata = . ;
+    }
+
+  .data :
+    {
+      _sdata = . ;
+      *(.data)
+      *(.data1)
+      *(.data.*)
+      *(.gnu.linkonce.d*)
+      _edata = . ;
+    }
+
+  /* C++ support. For each global and static local C++ object,
+   * GCC creates a small subroutine to construct the object. Pointers
+   * to these routines (not the routines themselves) are stored as
+   * simple, linear arrays in the .ctors section of the object file.
+   * Similarly, pointers to global/static destructor routines are
+   * stored in .dtors.
+   */
+
+  .ctors :
+    {
+      _sctors = . ;
+      *(.ctors)       /* Old ABI:  Unallocated */
+      *(.init_array)  /* New ABI:  Allocated */
+      _edtors = . ;
+    }
+
+  .dtors :
+    {
+      _sdtors = . ;
+      *(.dtors)       /* Old ABI:  Unallocated */
+      *(.fini_array)  /* New ABI:  Allocated */
+      _edtors = . ;
+    }
+
+  .bss :
+    {
+      _sbss = . ;
+      *(.bss)
+      *(.bss.*)
+      *(.sbss)
+      *(.sbss.*)
+      *(.gnu.linkonce.b*)
+      *(COMMON)
+      _ebss = . ;
+    }
+
+    /* Stabs debugging sections.    */
+
+    .stab 0 : { *(.stab) }
+    .stabstr 0 : { *(.stabstr) }
+    .stab.excl 0 : { *(.stab.excl) }
+    .stab.exclstr 0 : { *(.stab.exclstr) }
+    .stab.index 0 : { *(.stab.index) }
+    .stab.indexstr 0 : { *(.stab.indexstr) }
+    .comment 0 : { *(.comment) }
+    .debug_abbrev 0 : { *(.debug_abbrev) }
+    .debug_info 0 : { *(.debug_info) }
+    .debug_line 0 : { *(.debug_line) }
+    .debug_pubnames 0 : { *(.debug_pubnames) }
+    .debug_aranges 0 : { *(.debug_aranges) }
+}
--- a/configs/axoloti/scripts/kernel-space.ld
+++ b/configs/axoloti/scripts/kernel-space.ld
@ -0,0 +1,110 @@
+/****************************************************************************
+ * configs/axoloti/scripts/kernel-space.ld
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/* NOTE:  This depends on the memory.ld script having been included prior to
+ * this script.
+ */
+
+OUTPUT_ARCH(arm)
+EXTERN(_vectors)
+ENTRY(_stext)
+SECTIONS
+{
+    .text : {
+        _stext = ABSOLUTE(.);
+        *(.vectors)
+        *(.text .text.*)
+        *(.fixup)
+        *(.gnu.warning)
+        *(.rodata .rodata.*)
+        *(.gnu.linkonce.t.*)
+        *(.glue_7)
+        *(.glue_7t)
+        *(.got)
+        *(.gcc_except_table)
+        *(.gnu.linkonce.r.*)
+        _etext = ABSOLUTE(.);
+    } > kflash
+
+    .init_section : {
+        _sinit = ABSOLUTE(.);
+        *(.init_array .init_array.*)
+        _einit = ABSOLUTE(.);
+    } > kflash
+
+    .ARM.extab : {
+        *(.ARM.extab*)
+    } > kflash
+
+    __exidx_start = ABSOLUTE(.);
+    .ARM.exidx : {
+        *(.ARM.exidx*)
+    } > kflash
+
+    __exidx_end = ABSOLUTE(.);
+
+    _eronly = ABSOLUTE(.);
+
+    .data : {
+        _sdata = ABSOLUTE(.);
+        *(.data .data.*)
+        *(.gnu.linkonce.d.*)
+        CONSTRUCTORS
+        _edata = ABSOLUTE(.);
+    } > ksram AT > kflash
+
+    .bss : {
+        _sbss = ABSOLUTE(.);
+        *(.bss .bss.*)
+        *(.gnu.linkonce.b.*)
+        *(COMMON)
+        _ebss = ABSOLUTE(.);
+    } > ksram
+
+    /* Stabs debugging sections */
+
+    .stab 0 : { *(.stab) }
+    .stabstr 0 : { *(.stabstr) }
+    .stab.excl 0 : { *(.stab.excl) }
+    .stab.exclstr 0 : { *(.stab.exclstr) }
+    .stab.index 0 : { *(.stab.index) }
+    .stab.indexstr 0 : { *(.stab.indexstr) }
+    .comment 0 : { *(.comment) }
+    .debug_abbrev 0 : { *(.debug_abbrev) }
+    .debug_info 0 : { *(.debug_info) }
+    .debug_line 0 : { *(.debug_line) }
+    .debug_pubnames 0 : { *(.debug_pubnames) }
+    .debug_aranges 0 : { *(.debug_aranges) }
+}
--- a/configs/axoloti/scripts/ld.script
+++ b/configs/axoloti/scripts/ld.script
@ -0,0 +1,130 @@
+/****************************************************************************
+ * configs/axoloti/scripts/ld.script
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/* The STM32F427IGH6 has 1024KiB of FLASH beginning at address 0x0800:0000 and
+ * 256KiB of SRAM. SRAM is split up into four blocks:
+ *
+ * 1) 112KiB of SRAM beginning at address 0x2000:0000
+ * 2)  16KiB of SRAM beginning at address 0x2001:c000
+ * 3)  64KiB of SRAM beginning at address 0x2002:0000
+ * 4)  64KiB of CCM SRAM beginning at address 0x1000:0000
+ *
+ * When booting from FLASH, FLASH memory is aliased to address 0x0000:0000
+ * where the code expects to begin execution by jumping to the entry point in
+ * the 0x0800:0000 address
+ * range.
+ */
+
+MEMORY
+{
+    flash (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
+    sram (rwx) : ORIGIN = 0x20000000, LENGTH = 112K
+}
+
+OUTPUT_ARCH(arm)
+EXTERN(_vectors)
+ENTRY(_stext)
+SECTIONS
+{
+	.text : {
+		_stext = ABSOLUTE(.);
+		*(.vectors)
+		*(.text .text.*)
+		*(.fixup)
+		*(.gnu.warning)
+		*(.rodata .rodata.*)
+		*(.gnu.linkonce.t.*)
+		*(.glue_7)
+		*(.glue_7t)
+		*(.got)
+		*(.gcc_except_table)
+		*(.gnu.linkonce.r.*)
+		_etext = ABSOLUTE(.);
+	} > flash
+
+	.init_section : {
+		_sinit = ABSOLUTE(.);
+		*(.init_array .init_array.*)
+		_einit = ABSOLUTE(.);
+	} > flash
+
+	.ARM.extab : {
+		*(.ARM.extab*)
+	} > flash
+
+	__exidx_start = ABSOLUTE(.);
+	.ARM.exidx : {
+		*(.ARM.exidx*)
+	} > flash
+	__exidx_end = ABSOLUTE(.);
+
+	_eronly = ABSOLUTE(.);
+
+	/* The RAM vector table (if present) should lie at the beginning of SRAM */
+
+	.ram_vectors : {
+		*(.ram_vectors)
+	} > sram
+
+	.data : {
+		_sdata = ABSOLUTE(.);
+		*(.data .data.*)
+		*(.gnu.linkonce.d.*)
+		CONSTRUCTORS
+		_edata = ABSOLUTE(.);
+	} > sram AT > flash
+
+	.bss : {
+		_sbss = ABSOLUTE(.);
+		*(.bss .bss.*)
+		*(.gnu.linkonce.b.*)
+		*(COMMON)
+		_ebss = ABSOLUTE(.);
+	} > sram
+
+	/* Stabs debugging sections. */
+	.stab 0 : { *(.stab) }
+	.stabstr 0 : { *(.stabstr) }
+	.stab.excl 0 : { *(.stab.excl) }
+	.stab.exclstr 0 : { *(.stab.exclstr) }
+	.stab.index 0 : { *(.stab.index) }
+	.stab.indexstr 0 : { *(.stab.indexstr) }
+	.comment 0 : { *(.comment) }
+	.debug_abbrev 0 : { *(.debug_abbrev) }
+	.debug_info 0 : { *(.debug_info) }
+	.debug_line 0 : { *(.debug_line) }
+	.debug_pubnames 0 : { *(.debug_pubnames) }
+	.debug_aranges 0 : { *(.debug_aranges) }
+}
--- a/configs/axoloti/scripts/memory.ld
+++ b/configs/axoloti/scripts/memory.ld
@ -0,0 +1,101 @@
+/****************************************************************************
+ * configs/axoloti/scripts/memory.ld
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/* The STM32F427IGH6 has 1024KiB of FLASH beginning at address 0x0800:0000 and
+ * 256KiB of SRAM. SRAM is split up into four blocks:
+ *
+ * 1) 112KiB of SRAM beginning at address 0x2000:0000
+ * 2)  16KiB of SRAM beginning at address 0x2001:c000
+ * 3)  64KiB of SRAM beginning at address 0x2002:0000
+ * 4)  64KiB of CCM SRAM beginning at address 0x1000:0000
+ *
+ * When booting from FLASH, FLASH memory is aliased to address 0x0000:0000
+ * where the code expects to begin execution by jumping to the entry point in
+ * the 0x0800:0000 address range.
+ *
+ * For MPU support, the kernel-mode NuttX section is assumed to be 128Kb of
+ * FLASH and 4Kb of SRAM.  That is an excessive amount for the kernel which
+ * should fit into 64KB and, of course, can be optimized as needed (See
+ * also configs/axoloti/scripts/kernel-space.ld).  Allowing the
+ * additional does permit addition debug instrumentation to be added to the
+ * kernel space without overflowing the partition.
+ *
+ * Alignment of the user space FLASH partition is also a critical factor:
+ * The user space FLASH partition will be spanned with a single region of
+ * size 2**n bytes.  The alignment of the user-space region must be the same.
+ * As a consequence, as the user-space increases in size, the alignmment
+ * requirement also increases.
+ *
+ * This alignment requirement means that the largest user space FLASH region
+ * you can have will be 512KB at it would have to be positioned at
+ * 0x08800000.  If you change this address, don't forget to change the
+ * CONFIG_NUTTX_USERSPACE configuration setting to match and to modify
+ * the check in kernel/userspace.c.
+ *
+ * For the same reasons, the maximum size of the SRAM mapping is limited to
+ * 4KB.  Both of these alignment limitations could be reduced by using
+ * multiple regions to map the FLASH/SDRAM range or perhaps with some
+ * clever use of subregions.
+ *
+ * A detailed memory map for the 112KB SRAM region is as follows:
+ *
+ *   0x20000 0000:  Kernel .data region.  Typical size: 0.1KB
+ *   ------- ----   Kernel .bss  region.  Typical size: 1.8KB
+ *   0x20000 0800:  Kernel IDLE thread stack (approximate).  Size is
+ *                  determined by CONFIG_IDLETHREAD_STACKSIZE and
+ *                  adjustments for alignment.  Typical is 1KB.
+ *   ------- ----   Padded to 4KB
+ *   0x20000 1000:  User .data region.  Size is variable.
+ *   ------- ----   User .bss region  Size is variable.
+ *   0x20000 2000:  Beginning of kernel heap.  Size determined by
+ *                  CONFIG_MM_KERNEL_HEAPSIZE.
+ *   ------- ----   Beginning of user heap.  Can vary with other settings.
+ *   0x20001 c000:  End+1 of CPU RAM
+ */
+
+MEMORY
+{
+    /* 1024Kb FLASH */
+
+    kflash (rx)      : ORIGIN = 0x08000000, LENGTH = 128K
+    uflash (rx)      : ORIGIN = 0x08020000, LENGTH = 128K
+    xflash (rx)      : ORIGIN = 0x08040000, LENGTH = 768K
+
+    /* 112Kb of contiguous SRAM */
+
+    ksram (rwx)      : ORIGIN = 0x20000000, LENGTH = 4K
+    usram (rwx)      : ORIGIN = 0x20001000, LENGTH = 4K
+    xsram (rwx)      : ORIGIN = 0x20002000, LENGTH = 104K
+}
--- a/configs/axoloti/scripts/user-space.ld
+++ b/configs/axoloti/scripts/user-space.ld
@ -0,0 +1,126 @@
+/****************************************************************************
+ * configs/axoloti/scripts/user-space.ld
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/* NOTE:  This depends on the memory.ld script having been included prior to
+ * this script.
+ */
+
+/* Make sure that the critical memory management functions are in user-space.
+ * the user heap memory manager will reside in user-space but be usable both
+ * by kernel- and user-space code
+ */
+
+EXTERN(umm_initialize)
+EXTERN(umm_addregion)
+EXTERN(umm_trysemaphore)
+EXTERN(umm_givesemaphore)
+
+EXTERN(malloc)
+EXTERN(realloc)
+EXTERN(zalloc)
+EXTERN(free)
+
+OUTPUT_ARCH(arm)
+SECTIONS
+{
+    .userspace : {
+        *(.userspace)
+    } > uflash
+
+    .text : {
+        _stext = ABSOLUTE(.);
+        *(.text .text.*)
+        *(.fixup)
+        *(.gnu.warning)
+        *(.rodata .rodata.*)
+        *(.gnu.linkonce.t.*)
+        *(.glue_7)
+        *(.glue_7t)
+        *(.got)
+        *(.gcc_except_table)
+        *(.gnu.linkonce.r.*)
+        _etext = ABSOLUTE(.);
+    } > uflash
+
+    .init_section : {
+        _sinit = ABSOLUTE(.);
+        *(.init_array .init_array.*)
+        _einit = ABSOLUTE(.);
+    } > uflash
+
+    .ARM.extab : {
+        *(.ARM.extab*)
+    } > uflash
+
+    __exidx_start = ABSOLUTE(.);
+    .ARM.exidx : {
+        *(.ARM.exidx*)
+    } > uflash
+
+    __exidx_end = ABSOLUTE(.);
+
+    _eronly = ABSOLUTE(.);
+
+    .data : {
+        _sdata = ABSOLUTE(.);
+        *(.data .data.*)
+        *(.gnu.linkonce.d.*)
+        CONSTRUCTORS
+        _edata = ABSOLUTE(.);
+    } > usram AT > uflash
+
+    .bss : {
+        _sbss = ABSOLUTE(.);
+        *(.bss .bss.*)
+        *(.gnu.linkonce.b.*)
+        *(COMMON)
+        _ebss = ABSOLUTE(.);
+    } > usram
+
+    /* Stabs debugging sections */
+
+    .stab 0 : { *(.stab) }
+    .stabstr 0 : { *(.stabstr) }
+    .stab.excl 0 : { *(.stab.excl) }
+    .stab.exclstr 0 : { *(.stab.exclstr) }
+    .stab.index 0 : { *(.stab.index) }
+    .stab.indexstr 0 : { *(.stab.indexstr) }
+    .comment 0 : { *(.comment) }
+    .debug_abbrev 0 : { *(.debug_abbrev) }
+    .debug_info 0 : { *(.debug_info) }
+    .debug_line 0 : { *(.debug_line) }
+    .debug_pubnames 0 : { *(.debug_pubnames) }
+    .debug_aranges 0 : { *(.debug_aranges) }
+}
--- a/configs/axoloti/src/.gitignore
+++ b/configs/axoloti/src/.gitignore
@ -0,0 +1,2 @@
+/.depend
+/Make.dep
--- a/configs/axoloti/src/Makefile
+++ b/configs/axoloti/src/Makefile
@ -0,0 +1,67 @@
+############################################################################
+# configs/axoloti/src/Makefile
+#
+#   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+#   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name NuttX nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+-include $(TOPDIR)/Make.defs
+
+ASRCS =
+CSRCS = stm32_boot.c stm32_bringup.c
+
+ifeq ($(CONFIG_STM32_FMC),y)
+CSRCS += stm32_extmem.c
+endif
+
+ifeq ($(CONFIG_ARCH_LEDS),y)
+CSRCS += stm32_autoleds.c
+else
+CSRCS += stm32_userleds.c
+endif
+
+ifeq ($(CONFIG_AUDIO_ADAU1961),y)
+CSRCS += stm32_adau1961.c
+endif
+
+ifeq ($(CONFIG_ARCH_BUTTONS),y)
+CSRCS +=  stm32_buttons.c
+endif
+
+ifeq ($(CONFIG_STM32_SDIO),y)
+CSRCS += stm32_sdio.c
+endif
+
+ifeq ($(CONFIG_USBHOST),y)
+CSRCS += stm32_usbhost.c
+endif
+
+include $(TOPDIR)/configs/Board.mk
--- a/configs/axoloti/src/axoloti.h
+++ b/configs/axoloti/src/axoloti.h
@ -0,0 +1,251 @@
+/****************************************************************************
+ * configs/axoloti/src/axoloti.h
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __CONFIGS_AXOLOTI_SRC_AXOLOTI_H
+#define __CONFIGS_AXOLOTI_SRC_AXOLOTI_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+#include <stdint.h>
+#include <arch/stm32/chip.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * configuration
+ */
+
+/* Assume that we have everything */
+
+#define HAVE_USBDEV     1
+#define HAVE_USBHOST    1
+#define HAVE_SDIO       1
+#define HAVE_ADAU1961   1
+#define HAVE_SDRAM      1
+
+/* Can't support USB host if USB OTG HS is not enabled */
+
+#if !defined(CONFIG_STM32_OTGHS) || !defined(CONFIG_USBHOST)
+#  undef HAVE_USBHOST
+#endif
+
+/* Can't support USB device if USB OTG FS is not enabled */
+
+#if !defined(CONFIG_STM32_OTGFS) || !defined(CONFIG_USBDEV)
+#  undef HAVE_USBDEV
+#endif
+
+/* Can't support MMC/SD features if mountpoints or SDIO support are disabled */
+
+#if defined(CONFIG_DISABLE_MOUNTPOINT) || !defined(CONFIG_STM32_SDIO)
+#  undef HAVE_SDIO
+#endif
+
+/* The ADAU1961 depends on the ADAU1961 driver, I2C3, and SAI1 support */
+
+#if !defined(CONFIG_AUDIO_ADAU1961) || !defined(CONFIG_STM32_I2C3) || \
+    !defined(CONFIG_STM32_SAI1)
+#  undef HAVE_ADAU1961
+#endif
+
+/* Can't support SDRAM if the memory controller is disabled */
+
+#if !defined(CONFIG_STM32_FMC)
+#  undef HAVE_SDRAM
+#endif
+
+/****************************************************************************
+ * Audio Configuration
+ */
+
+#define ADAU1961_I2C_BUS 3      /* i2c3 */
+#define ADAU1961_I2C_ADDRESS 0x38
+#define ADAU1961_SAI_BUS SAI1_BLOCK_A
+
+/****************************************************************************
+ * SDIO Configuration
+ */
+
+#define SDIO_MINOR CONFIG_NSH_MMCSDMINOR
+#define SDIO_SLOTNO CONFIG_NSH_MMCSDSLOTNO
+
+/* SD Slot Card detect */
+
+#define GPIO_SDIO_NCD (GPIO_INPUT|GPIO_FLOAT|GPIO_EXTI|GPIO_PORTD|GPIO_PIN13)
+
+/****************************************************************************
+ * PROC File System Configuration
+ */
+
+#ifdef CONFIG_FS_PROCFS
+#  ifdef CONFIG_NSH_PROC_MOUNTPOINT
+#    define STM32_PROCFS_MOUNTPOINT CONFIG_NSH_PROC_MOUNTPOINT
+#  else
+#    define STM32_PROCFS_MOUNTPOINT "/proc"
+#  endif
+#endif
+
+/****************************************************************************
+ * LEDs
+ */
+
+#define GPIO_LED1 (GPIO_OUTPUT|GPIO_PUSHPULL|GPIO_SPEED_50MHz| \
+                   GPIO_OUTPUT_CLEAR|GPIO_PORTG|GPIO_PIN6)
+
+#define GPIO_LED2 (GPIO_OUTPUT|GPIO_PUSHPULL|GPIO_SPEED_50MHz| \
+                   GPIO_OUTPUT_CLEAR|GPIO_PORTC|GPIO_PIN6)
+
+/****************************************************************************
+ * Buttons
+ */
+
+#define MIN_IRQBUTTON BUTTON_USER
+#define MAX_IRQBUTTON BUTTON_USER
+#define NUM_IRQBUTTONS  1
+#define GPIO_BTN_USER (GPIO_INPUT|GPIO_PULLDOWN|GPIO_EXTI|GPIO_PORTA|GPIO_PIN10)
+
+/****************************************************************************
+ * USB Host (OTG High Speed)
+ */
+
+#define GPIO_OTGHS_PWRON (GPIO_OUTPUT|GPIO_OUTPUT_SET|GPIO_FLOAT| \
+                          GPIO_SPEED_100MHz|GPIO_PUSHPULL|GPIO_PORTD|GPIO_PIN7)
+
+#define GPIO_OTGHS_OVER  (GPIO_INPUT|GPIO_EXTI|GPIO_FLOAT| \
+                          GPIO_SPEED_100MHz|GPIO_PUSHPULL|GPIO_PORTG|GPIO_PIN13)
+
+/* #define GPIO_OTGHS_VBUS no vbus monitoring.... */
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public data
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_bringup
+ *
+ * Description:
+ *   Perform architecture-specific initialization
+ *
+ *   CONFIG_BOARD_LATE_INITIALIZE=y :
+ *     Called from board_late_initialize().
+ *
+ *   CONFIG_BOARD_LATE_INITIALIZE=y && CONFIG_LIB_BOARDCTL=y :
+ *     Called from the NSH library
+ *
+ ****************************************************************************/
+
+int stm32_bringup(void);
+
+/****************************************************************************
+ * Name: stm32_sdio_initialize
+ *
+ * Description:
+ *   Initialize SDIO-based MMC/SD card support
+ *
+ ****************************************************************************/
+
+#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_STM32_SDIO)
+int stm32_sdio_initialize(void);
+#endif
+
+/****************************************************************************
+ * Name: stm32_usbinitialize
+ *
+ * Description:
+ *   Called from stm32_usbinitialize very early in initialization to setup
+ *   USB-related GPIO pins for the STM32F4Discovery board.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_STM32_OTGHS
+void weak_function stm32_usbinitialize(void);
+#endif
+
+/****************************************************************************
+ * Name: stm32_usbhost_initialize
+ *
+ * Description:
+ *   Called at application startup time to initialize the USB host
+ *   functionality. This function will start a thread that will monitor for
+ *   device connection/disconnection events.
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_STM32_OTGHS) && defined(CONFIG_USBHOST)
+int stm32_usbhost_initialize(void);
+#endif
+
+/****************************************************************************
+ * Name: stm32_adau1961_initialize
+ *
+ * Description:
+ *   Called from stm32_bringup to initialize the adau1961 audio driver.
+ *
+ ****************************************************************************/
+
+#if defined(HAVE_ADAU1961)
+int stm32_adau1961_initialize(int minor);
+#endif
+
+/****************************************************************************
+ * Name: stm32_sdram_initialize
+ *
+ * Description:
+ *   Called from stm32_bringup to initialize external SDRAM access.
+ *
+ ****************************************************************************/
+
+#if defined(HAVE_SDRAM)
+int stm32_sdram_initialize(void);
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __CONFIGS_AXOLOTI_SRC_AXOLOTI_H */
--- a/configs/axoloti/src/stm32_adau1961.c
+++ b/configs/axoloti/src/stm32_adau1961.c
@ -0,0 +1,221 @@
+/****************************************************************************
+ * configs/axoloti/src/stm32_adau1961.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <debug.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/irq.h>
+#include <nuttx/i2c/i2c_master.h>
+#include <nuttx/audio/i2s.h>
+#include <nuttx/audio/adau1961.h>
+
+#include <arch/board/board.h>
+
+#include "stm32.h"
+#include "axoloti.h"
+
+#ifdef HAVE_ADAU1961
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+struct stm32_mwinfo_s
+{
+  /* Standard ADAU1961 interface */
+
+  struct adau1961_lower_s lower;
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static int adau1961_attach(FAR const struct adau1961_lower_s *lower,
+                           adau1961_handler_t isr, FAR void *arg)
+{
+  audinfo("TODO\n");
+  return 0;
+}
+
+static bool adau1961_enable(FAR const struct adau1961_lower_s *lower,
+                            bool enable)
+{
+  audinfo("TODO\n");
+  return 0;
+}
+
+static void adau1961_hw_reset(FAR const struct adau1961_lower_s *lower)
+{
+  audinfo("TODO\n");
+}
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* A reference to a structure of this type must be passed to the ADAU1961
+ * driver.  This structure provides information about the configuration
+ * of the ADAU1961 and provides some board-specific hooks.
+ *
+ * Memory for this structure is provided by the caller.  It is not copied
+ * by the driver and is presumed to persist while the driver is active.
+ */
+
+static struct stm32_mwinfo_s g_adau1961info =
+{
+  .lower =
+  {
+    .address   = ADAU1961_I2C_ADDRESS,
+    .frequency = I2C_SPEED_FAST,        /* 400 kHz */
+    .mclk      = STM32_HSE_FREQUENCY,   /* see MCO1 configuration */
+    .attach    = adau1961_attach,
+    .enable    = adau1961_enable,
+    .reset     = adau1961_hw_reset,
+  }
+};
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_adau1961_initialize
+ *
+ * Description:
+ *   This function is called by platform-specific, setup logic to configure
+ *   and register the ADAU1961 device.  This function will register the driver
+ *   as /dev/audio/pcm[x] where x is determined by the minor device number.
+ *
+ * Input Parameters:
+ *   minor - The input device minor number
+ *
+ * Returned Value:
+ *   Zero is returned on success.  Otherwise, a negated errno value is
+ *   returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int stm32_adau1961_initialize(int minor)
+{
+  FAR struct audio_lowerhalf_s *adau1961;
+  FAR struct i2c_master_s *i2c;
+  FAR struct i2s_dev_s *i2s;
+  static bool initialized = false;
+  char devname[12];
+  int ret;
+
+  audinfo("minor %d\n", minor);
+  DEBUGASSERT(minor >= 0 && minor <= 25);
+
+  /* Initialize the CODEC if we have not already done so */
+
+  if (!initialized)
+    {
+      /* Configure MC01 to drive the master clock of the CODEC at 8MHz */
+
+      stm32_configgpio(GPIO_MCO1);
+      stm32_mco1config(RCC_CFGR_MCO1_HSE, RCC_CFGR_MCO1PRE_NONE);
+
+      /* Get an instance of the I2C interface for the CODEC */
+
+      i2c = stm32_i2cbus_initialize(ADAU1961_I2C_BUS);
+      if (!i2c)
+        {
+          auderr("stm32_i2cbus_initialize failed\n");
+          ret = -ENODEV;
+          goto error;
+        }
+
+      /* Get an instance of the I2S interface for the CODEC data streams */
+
+      i2s = stm32_sai_initialize(ADAU1961_SAI_BUS);
+      if (!i2s)
+        {
+          auderr("stm32_sai_initialize failed\n");
+          ret = -ENODEV;
+          goto error;
+        }
+
+      /* Now we can use these I2C and I2S interfaces to initialize the
+       * CODEC which will return an audio interface.
+       */
+
+      adau1961 = adau1961_initialize(i2c, i2s, &g_adau1961info.lower);
+      if (!adau1961)
+        {
+          auderr("adau1961_initialize failed\n");
+          ret = -ENODEV;
+          goto error;
+        }
+
+      /* Create a device name */
+
+      snprintf(devname, 12, "pcm%d", minor);
+
+      /* Finally, we can register the ADAU1961/I2C/I2S audio device. */
+
+      ret = audio_register(devname, adau1961);
+      if (ret < 0)
+        {
+          auderr("failed to register /dev/%s device: %d\n", devname, ret);
+          goto error;
+        }
+
+      /* Now we are initialized */
+
+      initialized = true;
+    }
+
+  return OK;
+
+  /* Error exits. Unfortunately there is no mechanism in place now to
+   * recover resources from most errors on initialization failures.
+   */
+
+error:
+  return ret;
+}
+
+#endif /* HAVE_ADAU1961 */
--- a/configs/axoloti/src/stm32_boot.c
+++ b/configs/axoloti/src/stm32_boot.c
@ -0,0 +1,107 @@
+/****************************************************************************
+ * configs/axoloti/src/stm32_boot.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+
+#include <nuttx/board.h>
+#include <arch/board/board.h>
+
+#include "up_arch.h"
+#include "itm.h"
+
+#include "stm32.h"
+#include "axoloti.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_boardinitialize
+ *
+ * Description:
+ *   All STM32 architectures must provide the following entry point.  This
+ *   entry point is called early in the initialization -- after all memory
+ *   has been configured and mapped but before any devices have been
+ *   initialized.
+ *
+ ****************************************************************************/
+
+void stm32_boardinitialize(void)
+{
+#ifdef CONFIG_SCHED_CRITMONITOR
+  /* Make sure the high speed cycle counter is running.  It will be started
+   * automatically only if a debugger is connected.
+   */
+
+  putreg32(0xc5acce55, ITM_LAR);
+  modifyreg32(DWT_CTRL, 0, DWT_CTRL_CYCCNTENA_MASK);
+#endif
+
+#if defined(CONFIG_STM32_SPI1) || defined(CONFIG_STM32_SPI2) || \
+    defined(CONFIG_STM32_SPI3)
+  stm32_spidev_initialize();
+#endif
+
+#if defined(CONFIG_STM32_OTGHS) || defined(CONFIG_STM32_OTGFS)
+  stm32_usbinitialize();
+#endif
+}
+
+/****************************************************************************
+ * Name: board_late_initialize
+ *
+ * Description:
+ *   If CONFIG_BOARD_LATE_INITIALIZE is selected, then an additional
+ *   initialization call will be performed in the boot-up sequence to a
+ *   function called board_late_initialize().  board_late_initialize() will be
+ *   called immediately after up_initialize() is called and just before the
+ *   initial application is started.  This additional initialization phase
+ *   may be used, for example, to initialize board-specific device drivers.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_BOARD_LATE_INITIALIZE
+void board_late_initialize(void)
+{
+  (void)stm32_bringup();
+}
+#endif
--- a/configs/axoloti/src/stm32_bringup.c
+++ b/configs/axoloti/src/stm32_bringup.c
@ -0,0 +1,191 @@
+/****************************************************************************
+ * config/axoloti/src/stm32_bringup.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/mount.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <debug.h>
+#include <errno.h>
+
+#ifdef CONFIG_USBMONITOR
+#  include <nuttx/usb/usbmonitor.h>
+#endif
+
+#include "stm32.h"
+
+#ifdef CONFIG_STM32_OTGHS
+#  include "stm32_usbhost.h"
+#endif
+
+#ifdef CONFIG_BUTTONS
+#  include <nuttx/input/buttons.h>
+#endif
+
+#ifdef CONFIG_USERLED
+#  include <nuttx/leds/userled.h>
+#endif
+
+#include "axoloti.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_bringup
+ *
+ * Description:
+ *   Perform architecture-specific initialization
+ *
+ *   CONFIG_BOARD_LATE_INITIALIZE=y :
+ *     Called from board_late_initialize().
+ *
+ *   CONFIG_BOARD_LATE_INITIALIZE=n && CONFIG_LIB_BOARDCTL=y :
+ *     Called from the NSH library
+ *
+ ****************************************************************************/
+
+int stm32_bringup(void)
+{
+#ifdef HAVE_RTC_DRIVER
+  FAR struct rtc_lowerhalf_s *lower;
+#endif
+  int ret = OK;
+
+#ifdef HAVE_SDRAM
+  /* Initialize access to the SDRAM device */
+
+  ret = stm32_sdram_initialize();
+  if (ret != OK)
+    {
+      syslog(LOG_ERR, "stm32_sdram_initialize failed %d\n", ret);
+      return ret;
+    }
+#endif
+
+#ifdef HAVE_SDIO
+  /* Initialize the SDIO block driver */
+
+  ret = stm32_sdio_initialize();
+  if (ret != OK)
+    {
+      syslog(LOG_ERR, "stm32_sdio_initialize failed %d\n", ret);
+      return ret;
+    }
+#endif
+
+#ifdef HAVE_USBHOST
+  /* Initialize USB host operation.  stm32_usbhost_initialize() starts a
+   * thread will monitor for USB connection and disconnection events.
+   */
+
+  ret = stm32_usbhost_initialize();
+  if (ret != OK)
+    {
+      syslog(LOG_ERR, "stm32_usbhost_initialize failed %d\n", ret);
+      return ret;
+    }
+#endif
+
+#ifdef HAVE_USBMONITOR
+  /* Start the USB Monitor */
+
+  ret = usbmonitor_start();
+  if (ret != OK)
+    {
+      syslog(LOG_ERR, "usbmonitor_start failed %d\n", ret);
+      return ret;
+    }
+#endif
+
+#ifdef CONFIG_BUTTONS
+  /* Register the BUTTON driver */
+
+  ret = btn_lower_initialize("/dev/buttons");
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "btn_lower_initialize failed %d\n", ret);
+    }
+#endif
+
+#ifdef CONFIG_INPUT_REI2C
+  /* Register the rei2c driver */
+
+  ret = rei2c_initialize("/dev/re0");
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "rei2c_initialize failed %d\n", ret);
+    }
+#endif
+
+#ifdef CONFIG_USERLED
+  /* Register the LED driver */
+
+  ret = userled_lower_initialize("/dev/userleds");
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "userled_lower_initialize failed %d\n", ret);
+    }
+#endif
+
+#ifdef HAVE_ADAU1961
+  /* Configure ADAU1961 audio */
+
+  ret = stm32_adau1961_initialize(1);
+  if (ret != OK)
+    {
+      syslog(LOG_ERR, "stm32_adau1961_initialize failed %d\n", ret);
+    }
+#endif
+
+#ifdef CONFIG_FS_PROCFS
+  /* Mount the procfs file system */
+
+  ret = mount(NULL, STM32_PROCFS_MOUNTPOINT, "procfs", 0, NULL);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "failed to mount procfs at %s %d\n",
+             STM32_PROCFS_MOUNTPOINT, ret);
+    }
+#endif
+
+  return ret;
+}
--- a/configs/axoloti/src/stm32_buttons.c
+++ b/configs/axoloti/src/stm32_buttons.c
@ -0,0 +1,162 @@
+/****************************************************************************
+ * configs/axoloti/src/stm32_buttons.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <errno.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/board.h>
+#include <arch/board/board.h>
+
+#include "stm32.h"
+#include "axoloti.h"
+
+#ifdef CONFIG_ARCH_BUTTONS
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* Pin configuration for each axoloti button.  This array is indexed by
+ * the BUTTON_* definitions in board.h
+ */
+
+static const uint32_t g_buttons[NUM_BUTTONS] =
+{
+  GPIO_BTN_USER,
+};
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_button_initialize
+ *
+ * Description:
+ *   board_button_initialize() must be called to initialize button resources.
+ *   After that, board_buttons() may be called to collect the current state
+ *   of all buttons or board_button_irq() may be called to register button
+ *   interrupt handlers.
+ *
+ ****************************************************************************/
+
+void board_button_initialize(void)
+{
+  int i;
+
+  /* Configure the GPIO pins as inputs.
+   * EXTI interrupts are configured for all pins.
+   */
+
+  for (i = 0; i < NUM_BUTTONS; i++)
+    {
+      stm32_configgpio(g_buttons[i]);
+    }
+}
+
+/****************************************************************************
+ * Name: board_buttons
+ ****************************************************************************/
+
+uint32_t board_buttons(void)
+{
+  uint32_t ret = 0;
+  int i;
+
+  /* Check that state of each key */
+
+  for (i = 0; i < NUM_BUTTONS; i++)
+    {
+      /* A HI value means that the key is pressed. */
+
+      bool pressed = stm32_gpioread(g_buttons[i]);
+
+      /* Accumulate the set of depressed (not released) keys */
+
+      if (pressed)
+        {
+          ret |= (1 << i);
+        }
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Button support.
+ *
+ * Description:
+ *   board_button_initialize() must be called to initialize button resources.
+ *   After that, board_buttons() may be called to collect the current state
+ *   of all buttons or board_button_irq() may be called to register button
+ *   interrupt handlers.
+ *
+ *   After board_button_initialize() has been called, board_buttons() may be
+ *   called to collect the state of all buttons.  board_buttons() returns an
+ *   32-bit bit set with each bit associated with a button.  See the
+ *   BUTTON_*_BIT definitions in board.h for the meaning of each bit.
+ *
+ *   board_button_irq() may be called to register an interrupt handler that
+ *   will be called when a button is depressed or released.  The ID value is
+ *   a button enumeration value that uniquely identifies a button resource.
+ *   See the BUTTON_* definitions in board.h for the meaning of enumeration
+ *   value.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_ARCH_IRQBUTTONS
+int board_button_irq(int id, xcpt_t irqhandler, FAR void *arg)
+{
+  int ret = -EINVAL;
+
+  /* The following should be atomic */
+
+  if (id >= MIN_IRQBUTTON && id <= MAX_IRQBUTTON)
+    {
+      ret =
+        stm32_gpiosetevent(g_buttons[id], true, true, true, irqhandler, arg);
+    }
+
+  return ret;
+}
+#endif
+#endif /* CONFIG_ARCH_BUTTONS */
--- a/configs/axoloti/src/stm32_extmem.c
+++ b/configs/axoloti/src/stm32_extmem.c
@ -0,0 +1,323 @@
+/****************************************************************************
+ * configs/axoloti/src/stm32_extmem.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <arch/board/board.h>
+
+#include "chip.h"
+#include "up_arch.h"
+
+#include "stm32.h"
+#include "axoloti.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef CONFIG_STM32_FMC
+#warning "FMC is not enabled"
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* Axoloti SDRAM GPIO configuration */
+
+static const uint32_t g_sdram_config[] =
+{
+  /* Data lines */
+
+  GPIO_FMC_D0, GPIO_FMC_D1, GPIO_FMC_D2, GPIO_FMC_D3,
+  GPIO_FMC_D4, GPIO_FMC_D5, GPIO_FMC_D6, GPIO_FMC_D7,
+  GPIO_FMC_D8, GPIO_FMC_D9, GPIO_FMC_D10, GPIO_FMC_D11,
+  GPIO_FMC_D12, GPIO_FMC_D13, GPIO_FMC_D14, GPIO_FMC_D15,
+
+  /* Address lines */
+
+  GPIO_FMC_A0, GPIO_FMC_A1, GPIO_FMC_A2, GPIO_FMC_A3,
+  GPIO_FMC_A4, GPIO_FMC_A5, GPIO_FMC_A6, GPIO_FMC_A7,
+  GPIO_FMC_A8, GPIO_FMC_A9, GPIO_FMC_A10, GPIO_FMC_A11,
+  GPIO_FMC_A12,
+
+  /* Control lines */
+
+  GPIO_FMC_BA0,                 /* ba0 */
+  GPIO_FMC_BA1,                 /* ba1 */
+  GPIO_FMC_NBL0,                /* ldqm */
+  GPIO_FMC_NBL1,                /* udqm */
+  GPIO_FMC_SDCLK,               /* clk */
+  GPIO_FMC_SDCKE0_1,            /* cke */
+  GPIO_FMC_SDNWE_2,             /* we */
+  GPIO_FMC_SDNCAS,              /* cas */
+  GPIO_FMC_SDNRAS,              /* ras */
+  GPIO_FMC_SDNE0_1,             /* cs0 */
+  GPIO_FMC_SDNE1_2,             /* cs1 */
+};
+
+#define NUM_SDRAM_GPIOS (sizeof(g_sdram_config) / sizeof(uint32_t))
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_sdram_memtest
+ *
+ * Description:
+ *  Test the SDRAM.
+ *
+ ****************************************************************************/
+
+#define RAND_A 22695477
+#define RAND_C 1
+#define TEST_ITERATIONS 16
+
+int stm32_sdram_memtest(void *base, uint32_t size)
+{
+  volatile int iter;
+  volatile int i;
+
+  /* Linear write with linear congruential generator values */
+
+  for (iter = 0; iter < TEST_ITERATIONS; iter++)
+    {
+      uint32_t x = iter;
+
+      /* Write */
+
+      for (i = 0; i < size / 4; i++)
+        {
+          x = (RAND_A * x) + RAND_C;
+          ((volatile uint32_t *)base)[i] = x;
+        }
+
+      /* Read/verify */
+
+      x = iter;
+      for (i = 0; i < size / 4; i++)
+        {
+          x = (RAND_A * x) + RAND_C;
+          if (((volatile uint32_t *)base)[i] != x)
+            {
+              return -1;
+            }
+        }
+    }
+
+  /* Scattered byte write at linear congruential generator addresses */
+
+  for (iter = 0; iter < TEST_ITERATIONS; iter++)
+    {
+      uint32_t x = iter;
+
+      /* Write */
+
+      for (i = 0; i < 1024 * 1024; i++)
+        {
+          x = (RAND_A * x) + RAND_C;
+          ((volatile uint8_t *)base)[x & (size - 1)] = (uint8_t) i;
+        }
+
+      /* Read/verify */
+
+      x = iter;
+      for (i = 0; i < 1024 * 1024; i++)
+        {
+          x = (RAND_A * x) + RAND_C;
+          if (((volatile uint8_t *)base)[x & (size - 1)] != (uint8_t) i)
+            {
+              return -1;
+            }
+        }
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: stm32_sdram_initialize
+ *
+ * Description:
+ *   Called from stm32_bringup to initialize external SDRAM access.
+ *   The Axoloti uses an Alliance Memory AS4C4M16SA SDRAM.
+ *
+ ****************************************************************************/
+
+int stm32_sdram_initialize(void)
+{
+  uint32_t val;
+  int i;
+
+  /* Configure SDRAM GPIOs */
+
+  for (i = 0; i < NUM_SDRAM_GPIOS; i++)
+    {
+      stm32_configgpio(g_sdram_config[i]);
+    }
+
+  /* Enable the FMC */
+
+  stm32_fmc_enable();
+
+  /* Go through the SDRAM initialization steps per the reference manual.
+   * The sdclk period is set to 2 x hclk. That is: 168 /2 = 84 MHz
+   * This gives a clock period of about 11.9 ns
+   */
+
+  /* Step 1:
+   * Program the memory device features into the FMC_SDCRx register. The
+   * SDRAM clock frequency, RBURST and RPIPE must be programmed in the
+   * FMC_SDCR1 register.
+   */
+
+  val = FMC_SDCR_RPIPE_1 |      /* rpipe = 1 hclk */
+    FMC_SDCR_READBURST |        /* read burst enabled */
+    FMC_SDCR_SDCLK_2X |         /* sdclk = 2 hclk */
+    FMC_SDCR_CAS_LATENCY_2 |    /* cas latency = 2 cycles */
+    FMC_SDCR_NBANKS_4 |         /* 4 internal banks */
+    FMC_SDCR_WIDTH_16 |         /* width = 16 bits */
+    FMC_SDCR_ROWS_12 |          /* numrows = 12 */
+    FMC_SDCR_COLS_8;            /* numcols = 8 bits */
+  stm32_fmc_sdram_set_control(1, val);
+
+  /* Step 2:
+   * Program the memory device timing into the FMC_SDTRx register.  The
+   * TRP and TRC timings must be programmed in the FMC_SDTR1 register.
+   */
+
+  val = FMC_SDTR_TRCD(2) |      /* ras to cas delay 21ns => 2x11.90ns */
+    FMC_SDTR_TRP(2) |           /* row precharge 21ns => 2x11.90ns */
+    FMC_SDTR_TRC(6) |           /* row cycle time 63ns => 6x11.9ns */
+    FMC_SDTR_TRAS(4) |          /* row active time 42ns = >4x11.9ns */
+    FMC_SDTR_TWR(4) |           /* write to precharge 42ns => 4x11.9ns */
+    FMC_SDTR_TXSR(6) |          /* exit self refresh 65ns => 6x11.9ns */
+    FMC_SDTR_TMRD(2);           /* load mode register to active 2 clks */
+  stm32_fmc_sdram_set_timing(1, val);
+
+  /* Step 3:
+   * Set MODE bits to ‘001’ and configure the Target Bank bits (CTB1
+   * and/or CTB2) in the FMC_SDCMR register to start delivering the clock
+   * to the memory (SDCKE is driven high).
+   */
+
+  val = FMC_SDCMR_BANK_1 | FMC_SDCMR_CMD_CLK_ENABLE;
+  stm32_fmc_sdram_command(val);
+
+  /* Step 4:
+   * Wait during the prescribed delay period. Typical delay is around 100
+   * μs (refer to the SDRAM datasheet for the required delay after power-up).
+   */
+
+  nxsig_usleep(1000);
+
+  /* Step 5:
+   * Set MODE bits to ‘010’ and configure the Target Bank bits (CTB1
+   * and/or CTB2) in the FMC_SDCMR register to issue a “Precharge All”
+   * command.
+   */
+
+  val = FMC_SDCMR_BANK_1 | FMC_SDCMR_CMD_PALL;
+  stm32_fmc_sdram_command(val);
+
+  /* Step 6:
+   * Set MODE bits to ‘011’, and configure the Target Bank bits (CTB1
+   * and/or CTB2) as well as the number of consecutive Auto-refresh
+   * commands (NRFS) in the FMC_SDCMR register. Refer to the SDRAM
+   * datasheet for the number of Auto-refresh commands that should be
+   * issued. Typical number is 8.
+   */
+
+  val = FMC_SDCMR_NRFS(5) | FMC_SDCMR_BANK_1 | FMC_SDCMR_CMD_AUTO_REFRESH;
+  stm32_fmc_sdram_command(val);
+
+  /* Step 7:
+   * Configure the MRD field according to your SDRAM device, set the MODE
+   * bits to '100', and configure the Target Bank bits (CTB1 and/or CTB2)
+   * in the FMC_SDCMR register to issue a "Load Mode Register" command in
+   * order to program the SDRAM. In particular:
+   * a) The CAS latency must be selected following configured value in
+   *    FMC_SDCR1/2 registers
+   * b) The Burst Length (BL) of 1 must be selected by configuring the
+   *    M[2:0] bits to 000 in the mode register (refer to the SDRAM
+   *    datasheet). If the Mode Register is not the same for both SDRAM
+   *    banks, this step has to be repeated twice, once for each bank,
+   *    and the Target Bank bits set accordingly.
+   */
+
+  val = FMC_SDCMR_MDR_BURST_LENGTH_2 |
+    FMC_SDCMR_MDR_BURST_TYPE_SEQUENTIAL |
+    FMC_SDCMR_MDR_CAS_LATENCY_2 |
+    FMC_SDCMR_MDR_MODE_NORMAL |
+    FMC_SDCMR_MDR_WBL_SINGLE | FMC_SDCMR_BANK_1 | FMC_SDCMR_CMD_LOAD_MODE;
+  stm32_fmc_sdram_command(val);
+
+  /* Step 8:
+   * Program the refresh rate in the FMC_SDRTR register
+   * The refresh rate corresponds to the delay between refresh cycles. Its
+   * value must be adapted to SDRAM devices.
+   */
+
+  stm32_fmc_sdram_set_refresh_rate(1292);       /* (64ms/4096rows) x 84MHz) - 20 */
+
+  /* Step 9:
+   * For mobile SDRAM devices, to program the extended mode register it
+   * should be done once the SDRAM device is initialized: First, a dummy
+   * read access should be performed while BA1=1 and BA=0 (refer to SDRAM
+   * address mapping section for BA[1:0] address mapping) in order to select
+   * the extended mode register instead of Load mode register and then
+   * program the needed value.
+   */
+
+  /* Setting EMRS is optional and we're not bothering ... */
+
+  /* Enable memory writes for bank 1 */
+
+  stm32_fmc_sdram_write_protect(1, false);
+
+  /* Wait for the controller to be ready */
+
+  stm32_fmc_sdram_wait();
+  return OK;
+}
--- a/configs/axoloti/src/stm32_sdio.c
+++ b/configs/axoloti/src/stm32_sdio.c
@ -0,0 +1,172 @@
+/****************************************************************************
+ * config/axoloti/src/stm32_sdio.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/sdio.h>
+#include <nuttx/mmcsd.h>
+
+#include "stm32.h"
+#include "axoloti.h"
+
+#ifdef HAVE_SDIO
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Card detections requires card support and a card detection GPIO */
+
+#define HAVE_NCD 1
+#if !defined(HAVE_SDIO) || !defined(GPIO_SDIO_NCD)
+#undef HAVE_NCD
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static FAR struct sdio_dev_s *g_sdio_dev;
+#ifdef HAVE_NCD
+static bool g_sd_inserted = 0xff;       /* Impossible value */
+#endif
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_ncd_interrupt
+ *
+ * Description:
+ *   Card detect interrupt handler.
+ *
+ ****************************************************************************/
+
+#ifdef HAVE_NCD
+static int stm32_ncd_interrupt(int irq, FAR void *context, FAR void *arg)
+{
+  bool present;
+
+  present = !stm32_gpioread(GPIO_SDIO_NCD);
+  if (present != g_sd_inserted)
+    {
+      sdio_mediachange(g_sdio_dev, present);
+      g_sd_inserted = present;
+    }
+
+  return OK;
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_sdio_initialize
+ *
+ * Description:
+ *   Initialize SDIO-based MMC/SD card support
+ *
+ ****************************************************************************/
+
+int stm32_sdio_initialize(void)
+{
+  int ret;
+
+#ifdef HAVE_NCD
+  bool cd_status;
+
+  /* Configure the card detect GPIO */
+
+  stm32_configgpio(GPIO_SDIO_NCD);
+
+  /* Register an interrupt handler for the card detect pin */
+
+  (void)stm32_gpiosetevent(GPIO_SDIO_NCD, true, true, true,
+                           stm32_ncd_interrupt, NULL);
+
+#endif
+
+  /* Mount the SDIO-based MMC/SD block driver.
+   * First, get an instance of the SDIO interface
+   */
+
+  finfo("Initializing SDIO slot %d\n", SDIO_SLOTNO);
+  g_sdio_dev = sdio_initialize(SDIO_SLOTNO);
+  if (!g_sdio_dev)
+    {
+      ferr("ERROR: Failed to initialize SDIO slot %d\n", SDIO_SLOTNO);
+      return -ENODEV;
+    }
+
+  /* Now bind the SDIO interface to the MMC/SD driver */
+
+  finfo("Bind SDIO to the MMC/SD driver, minor=%d\n", SDIO_MINOR);
+  ret = mmcsd_slotinitialize(SDIO_MINOR, g_sdio_dev);
+  if (ret != OK)
+    {
+      ferr("ERROR: Failed to bind SDIO to the MMC/SD driver: %d\n", ret);
+      return ret;
+    }
+
+  finfo("Successfully bound SDIO to the MMC/SD driver\n");
+
+#ifdef HAVE_NCD
+  /* Use SD card detect pin to check if a card is g_sd_inserted */
+
+  cd_status = !stm32_gpioread(GPIO_SDIO_NCD);
+  finfo("Card detect : %d\n", cd_status);
+  sdio_mediachange(g_sdio_dev, cd_status);
+#else
+  /* Assume that the SD card is inserted.  What choice do we have? */
+
+  sdio_mediachange(g_sdio_dev, true);
+#endif
+
+  return OK;
+}
+
+#endif /* HAVE_SDIO */
--- a/configs/axoloti/src/stm32_usbhost.c
+++ b/configs/axoloti/src/stm32_usbhost.c
@ -0,0 +1,279 @@
+/****************************************************************************
+ * configs/axoloti/src/stm32_usbhost.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <sched.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/kthread.h>
+#include <nuttx/usb/usbdev.h>
+#include <nuttx/usb/usbhost.h>
+#include <nuttx/usb/usbdev_trace.h>
+
+#include "up_arch.h"
+#include "stm32.h"
+#include "stm32_otghs.h"
+#include "axoloti.h"
+
+#ifdef CONFIG_STM32_OTGHS
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#if defined(CONFIG_USBDEV) || defined(CONFIG_USBHOST)
+#define HAVE_USB 1
+#else
+#warning "CONFIG_STM32_OTGHS is enabled but neither CONFIG_USBDEV nor CONFIG_USBHOST"
+#undef HAVE_USB
+#endif
+
+#ifndef CONFIG_AXOLOTI_USBHOST_PRIO
+#define CONFIG_AXOLOTI_USBHOST_PRIO 100
+#endif
+
+#ifndef CONFIG_AXOLOTI_USBHOST_STACKSIZE
+#define CONFIG_AXOLOTI_USBHOST_STACKSIZE 1024
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+#ifdef CONFIG_USBHOST
+static struct usbhost_connection_s *g_usbconn;
+#endif
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: usbhost_waiter
+ *
+ * Description:
+ *   Wait for USB devices to be connected.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_USBHOST
+static int usbhost_waiter(int argc, char *argv[])
+{
+  struct usbhost_hubport_s *hport;
+  uinfo("Running\n");
+
+  for (; ; )
+    {
+      /* Wait for the device to change state */
+
+      DEBUGVERIFY(CONN_WAIT(g_usbconn, &hport));
+      uinfo("%s\n", hport->connected ? "connected" : "disconnected");
+
+      /* Did we just become connected? */
+
+      if (hport->connected)
+        {
+          /* Yes.. enumerate the newly connected device */
+
+         (void)CONN_ENUMERATE(g_usbconn, hport);
+        }
+    }
+
+  /* Keep the compiler from complaining */
+
+  return 0;
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_usbinitialize
+ *
+ * Description:
+ *   Called from stm32_usbinitialize very early in inialization to setup
+ *   USB-related GPIO pins for the Axoloti board.
+ *
+ ****************************************************************************/
+
+void stm32_usbinitialize(void)
+{
+#ifdef CONFIG_STM32_OTGHS
+  stm32_configgpio(GPIO_OTGHS_PWRON);
+  stm32_configgpio(GPIO_OTGHS_OVER);
+#endif
+}
+
+/****************************************************************************
+ * Name: stm32_usbhost_vbusdrive
+ *
+ * Description:
+ *   Enable/disable driving of VBUS 5V output. This function must be provided
+ *   be each platform that implements the STM32 OTG HS host interface
+ *
+ * Input Parameters:
+ *   iface  - For future growth to handle multiple USB host interface. Should
+ *            be zero.
+ *   enable - true: enable VBUS power; false: disable VBUS power
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_USBHOST
+void stm32_usbhost_vbusdrive(int iface, bool enable)
+{
+  DEBUGASSERT(iface == 0);
+  if (enable)
+    {
+      /* Enable the Power Switch by driving the enable pin low */
+
+      stm32_gpiowrite(GPIO_OTGHS_PWRON, false);
+    }
+  else
+    {
+      /* Disable the Power Switch by driving the enable pin high */
+
+      stm32_gpiowrite(GPIO_OTGHS_PWRON, true);
+    }
+}
+#endif
+
+/****************************************************************************
+ * Name: stm32_setup_overcurrent
+ *
+ * Description:
+ *   Setup to receive an interrupt-level callback if an overcurrent condition
+ *   is detected.
+ *
+ * Input Parameters:
+ *   handler - New overcurrent interrupt handler
+ *   arg     - The argument provided for the interrupt handler
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success. Otherwise, a negated errno value is
+ *   returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_USBHOST
+int stm32_setup_overcurrent(xcpt_t handler, void *arg)
+{
+  return stm32_gpiosetevent(GPIO_OTGHS_OVER, true, true, true, handler, arg);
+}
+#endif
+
+/****************************************************************************
+ * Name: stm32_usbhost_initialize
+ *
+ * Description:
+ *   Called at application startup time to initialize the USB host
+ *   functionality. This function will start a thread that will monitor for
+ *   device connection/disconnection events.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_USBHOST
+int stm32_usbhost_initialize(void)
+{
+  int pid;
+  int ret;
+
+  /* First, register all of the class drivers needed to support the drivers
+   * that we care about:
+   */
+  uinfo("Register class drivers\n");
+
+#ifdef CONFIG_USBHOST_MSC
+  /* Register the USB mass storage class class */
+
+  ret = usbhost_msc_initialize();
+  if (ret != OK)
+    {
+      uerr("ERROR: Failed to register the mass storage class: %d\n", ret);
+    }
+#endif
+
+#ifdef CONFIG_USBHOST_HIDKBD
+  /* Initialize the HID keyboard class */
+
+  ret = usbhost_kbdinit();
+  if (ret != OK)
+    {
+      uerr("ERROR: Failed to register the HID keyboard class\n");
+    }
+#endif
+
+#ifdef CONFIG_USBHOST_HIDMOUSE
+  /* Initialize the HID mouse class */
+
+  ret = usbhost_mouse_init();
+  if (ret != OK)
+    {
+      uerr("ERROR: Failed to register the HID mouse class\n");
+    }
+#endif
+
+  /* Then get an instance of the USB host interface */
+
+  uinfo("Initialize USB host\n");
+  g_usbconn = stm32_otghshost_initialize(0);
+  if (g_usbconn)
+    {
+      /* Start a thread to handle device connection. */
+
+      uinfo("Start usbhost_waiter\n");
+      pid =
+        kthread_create("usbhost", CONFIG_AXOLOTI_USBHOST_PRIO,
+                       CONFIG_AXOLOTI_USBHOST_STACKSIZE,
+                       (main_t) usbhost_waiter, (FAR char *const *)NULL);
+      return pid < 0 ? -ENOEXEC : OK;
+    }
+
+  return -ENODEV;
+}
+#endif
+
+#endif /* CONFIG_STM32_OTGHS */
--- a/configs/axoloti/src/stm32_userleds.c
+++ b/configs/axoloti/src/stm32_userleds.c
@ -0,0 +1,108 @@
+/****************************************************************************
+ * configs/axoloti/src/stm32_userleds.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Jason T. Harris <sirmanlypowers@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <debug.h>
+
+#include <nuttx/board.h>
+#include <nuttx/power/pm.h>
+#include <arch/board/board.h>
+
+#include "chip.h"
+#include "up_arch.h"
+#include "up_internal.h"
+
+#include "stm32.h"
+#include "axoloti.h"
+
+#ifndef CONFIG_ARCH_LEDS
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This array maps an LED number to GPIO pin configuration */
+
+static uint32_t g_ledcfg[BOARD_NLEDS] =
+{
+  GPIO_LED1, GPIO_LED2,
+};
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_userled_initialize
+ ****************************************************************************/
+
+void board_userled_initialize(void)
+{
+  /* Configure LED1-2 GPIOs for output */
+
+  stm32_configgpio(GPIO_LED1);
+  stm32_configgpio(GPIO_LED2);
+}
+
+/****************************************************************************
+ * Name: board_userled
+ ****************************************************************************/
+
+void board_userled(int led, bool ledon)
+{
+  if ((unsigned)led < BOARD_NLEDS)
+    {
+      stm32_gpiowrite(g_ledcfg[led], ledon);
+    }
+}
+
+/****************************************************************************
+ * Name: board_userled_all
+ ****************************************************************************/
+
+void board_userled_all(uint8_t ledset)
+{
+  stm32_gpiowrite(GPIO_LED1, (ledset & BOARD_LED1_BIT) == 0);
+  stm32_gpiowrite(GPIO_LED2, (ledset & BOARD_LED2_BIT) == 0);
+}
+
+#endif /* !CONFIG_ARCH_LEDS */