README
======
This README file discusses the port of NuttX to the Silicon Labs EFM32™ Gecko Starter Kit (EFM32-G8XX-STK). The Gecko Starter Kit features:
• EFM32G890F128 MCU with 128 kB flash and 16 kB RAM
• 32.768 kHz crystal
• 32 MHz crystal
• Advanced Energy Monitoring
• Touch slider
• 4x40 LCD
• 4 User LEDs
• 2 pushbutton switches
• Reset button and a switch to disconnect the battery.
• On-board SEGGER J-Link USB emulator
• ARM 20 pin JTAG/SWD standard Debug in/out connector
LEDs
====
The EFM32 Gecko Start Kit has four yellow LEDs. These LEDs are connected
as follows:
------------------------------------- --------------------
EFM32 PIN BOARD SIGNALS
------------------------------------- --------------------
C0/USART1_TX#0/PCNT0_S0IN#2/ACMP0_CH0 MCU_PC0 UIF_LED0
C1/USART1_RX#0/PCNT0_S1IN#2/ACMP0_CH1 MCU_PC1 UIF_LED1
C2/USART2_TX#0/ACMP0_CH2 MCU_PC2 UIF_LED2
C3/USART2_RX#0/ACMP0_CH3 MCU_PC3 UIF_LED3
------------------------------------- --------------------
All LEDs are grounded and so are illuminated by outputting a high
value to the LED.
These LEDs are not used by the board port unless CONFIG_ARCH_LEDS is
defined. In that case, the usage by the board port is defined in
include/board.h and src/efm32_autoleds.c. The LEDs are used to
encode OS-related events as follows:
SYMBOL Meaning LED1* LED2 LED3 LED4
----------------- ----------------------- ------ ----- ----- ------
LED_STARTED NuttX has been started ON OFF OFF OFF
LED_HEAPALLOCATE Heap has been allocated OFF ON OFF OFF
LED_IRQSENABLED Interrupts enabled ON ON OFF OFF
LED_STACKCREATED Idle stack created OFF OFF ON OFF
LED_INIRQ In an interrupt** ON N/C N/C OFF
LED_SIGNAL In a signal handler*** N/C ON N/C OFF
LED_ASSERTION An assertion failed ON ON N/C OFF
LED_PANIC The system has crashed N/C N/C N/C ON
LED_IDLE STM32 is is sleep mode (Optional, not used)
* If LED1, LED2, LED3 are statically on, then NuttX probably failed to boot
and these LEDs will give you some indication of where the failure was
** The normal state is LED3 ON and LED1 faintly glowing. This faint glow
is because of timer interrupt that result in the LED being illuminated
on a small proportion of the time.
*** LED2 may also flicker normally if signals are processed.
Configurations
==============
Each EFM32 Gecko Starter Kit configuration is maintained in a sub-director
and can be selected as follow:
cd tools
./configure.sh efm32-g8xx-stk/<subdir>
cd -
. ./setenv.sh
If this is a Windows native build, then configure.bat should be used
instead of configure.sh:
configure.bat STM32F4Discovery\<subdir>
Where <subdir> is one of the following:
nsh:
---
Configures the NuttShell (nsh) located at apps/examples/nsh. The
Configuration enables the serial interfaces on USARTx. Support for
builtin applications is enabled, but in the base configuration no
builtin applications are selected (see NOTES below).
NOTES:
1. This configuration uses the mconf-based configuration tool. To
change this configuration using that tool, you should:
a. Build and install the kconfig-mconf tool. See nuttx/README.txt
and misc/tools/
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. By default, this configuration uses the CodeSourcery toolchain
for Windows and builds under Cygwin (or probably MSYS). That
can easily be reconfigured, of course.
CONFIG_HOST_WINDOWS=y : Builds under Windows
CONFIG_WINDOWS_CYGWIN=y : Using Cygwin
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery for Windows
