README ^^^^^^ This README discusses issues unique to NuttX configurations for the Atmel SAM4S Xplained development board. This board features the ATSAM4S16C MCU with 1MB FLASH and 128KB. The SAM4S Xplained features: - 120 MHz Cortex-M4 with MPU - 12MHz crystal (no 32.768KHz crystal) - Segger J-Link JTAG emulator on-board for program and debug - MICRO USB A/B connector for USB connectivity - IS66WV51216DBLL ISSI SRAM 8Mb 512K x 16 55ns PSRAM 2.5v-3.6v - Four Atmel QTouch buttons - External voltage input - Four LEDs, two controllable from software - Xplained expansion headers - Footprint for external serial Flash (not fitted) Contents ^^^^^^^^ - PIO Muliplexing - Development Environment - GNU Toolchain Options - IDEs - NuttX EABI "buildroot" Toolchain - NuttX OABI "buildroot" Toolchain - NXFLAT Toolchain - Buttons and LEDs - Serial Consoles - SAM4S Xplained-specific Configuration Options - Configurations PIO Muliplexing ^^^^^^^^^^^^^^^ PA0 SMC_A17 PB0 J2.3 default PC0 SMC_D0 PA1 SMC_A18 PB1 J2.4 PC1 SMC_D1 PA2 J3.7 default PB2 J1.3 & J4.3 PC2 SMC_D2 PA3 J1.1 & J4.1 PB3 J1.4 & J4.4 PC3 SMC_D3 PA4 J1.2 & J4.2 PB4 JTAG PC4 SMC_D4 PA5 User_button BP2 PB5 JTAG PC5 SMC_D5 PA6 J3.7 optional PB6 JTAG PC6 SMC_D6 PA7 CLK_32K PB7 JTAG PC7 SMC_D7 PA8 CLK_32K PB8 CLK_12M PC8 SMC_NWE PA9 RX_UART0 PB9 CLK_12M PC9 Power on detect PA10 TX_UART0 PB10 USB_DDM PC10 User LED D9 PA11 J3.2 default PB11 USB_DDP PC11 SMC_NRD PA12 MISO PB12 ERASE PC12 J2.2 PA13 MOSI PB13 J2.3 optional PC13 J2.7 PA14 SPCK PB14 N/A PC14 SMC_NCS0 PA15 J3.5 PC15 SMC_NSC1 PA16 J3.6 PC16 N/A PA17 J2.5 PC17 User LED D10 PA18 J3.4 & SMC_A14 PC18 SMC_A0 PA19 J3.4 optional & SMC_A15 PC19 SMC_A1 PA20 J3.1 & SMC_A16 PC20 SMC_A2 PA21 J2.6 PC21 SMC_A3 PA22 J2.1 PC22 SMC_A4 PA23 J3.3 PC23 SMC_A5 PA24 TSLIDR_SL_SN PC24 SMC_A6 PA25 TSLIDR_SL_SNSK PC25 SMC_A7 PA26 TSLIDR_SM_SNS PC26 SMC_A8 PA27 TSLIDR_SM_SNSK PC27 SMC_A9 PA28 TSLIDR_SR_SNS PC28 SMC_A10 PA29 TSLIDR_SR_SNSK PC29 SMC_A11 PA30 J4.5 PC30 SMC_A12 PA31 J1.5 PC31 SMC_A13 Development Environment ^^^^^^^^^^^^^^^^^^^^^^^ Several possibile development enviorments may be use: - Linux or OSX native - Cygwin unders Windows - MinGW + MSYS under Windows - Windows native (with GNUMake from GNUWin32). All testing has been performed using Cygwin under Windows. The source has been built only using the GNU toolchain (see below). Other toolchains will likely cause problems. GNU Toolchain Options ^^^^^^^^^^^^^^^^^^^^^ The NuttX make system has been modified to support the several different toolchain options. All testing has been conducted using the NuttX buildroot toolchain. To use the CodeSourcery, devkitARM or Raisonance GNU toolchain, you simply need to add one of the following configuration options to your .config (or defconfig) file: CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery under Windows CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYL=y : CodeSourcery under Linux CONFIG_ARMV7M_TOOLCHAIN_ATOLLIC=y : Atollic toolchain for Windos CONFIG_ARMV7M_TOOLCHAIN_DEVKITARM=y : devkitARM under Windows CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default) CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIL=y : Generic GCC ARM EABI toolchain for Linux CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW=y : Generic GCC ARM EABI toolchain for Windows If you are not using CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT, then you may also have to modify the PATH in the setenv.h file if your make cannot find the tools. NOTE about Windows native toolchains ------------------------------------ The CodeSourcery (for Windows), Atollic, and devkitARM toolchains are Windows native toolchains. The CodeSourcery (for Linux), NuttX buildroot, and, perhaps, the generic GCC toolchains are Cygwin and/or Linux native toolchains. There are several limitations to using a Windows based toolchain in a Cygwin environment. The three biggest are: 1. The Windows toolchain cannot follow Cygwin paths. Path conversions are performed automatically in the Cygwin makefiles using the 'cygpath' utility but you might easily find some new path problems. If so, check out 'cygpath -w' 2. Windows toolchains cannot follow Cygwin symbolic links. Many symbolic links are used in Nuttx (e.g., include/arch). The make system works around these problems for the Windows tools by copying directories instead of linking them. But this can also cause some confusion for you: For example, you may edit a file in a "linked" directory and find that your changes had no effect. That is because you are building the copy of the file in the "fake" symbolic directory. If you use a Windows toolchain, you should get in the habit of making like this: make clean_context all An alias in your .bashrc file might make that less painful. 3. Dependencies are not made when using Windows versions of the GCC. This is because the dependencies are generated using Windows pathes which do not work with the Cygwin make. MKDEP = $(TOPDIR)/tools/mknulldeps.sh NOTE 1: Older CodeSourcery toolchains (2009q1) do not work with default optimization level of -Os (See Make.defs). It will work with -O0, -O1, or -O2, but not with -Os. NOTE 2: The devkitARM toolchain includes a version of MSYS make. Make sure that the paths to Cygwin's /bin and /usr/bin directories appear BEFORE the devkitARM path or will get the wrong version of make. IDEs ^^^^ NuttX is built using command-line make. It can be used with an IDE, but some effort will be required to create the project. Makefile Build -------------- Under Eclipse, it is pretty easy to set up an "empty makefile project" and simply use the NuttX makefile to build the system. That is almost for free under Linux. Under Windows, you will need to set up the "Cygwin GCC" empty makefile project in order to work with Windows (Google for "Eclipse Cygwin" - there is a lot of help on the internet). Native Build ------------ Here are a few tips before you start that effort: 1) Select the toolchain that you will be using in your .config file 2) Start the NuttX build at least one time from the Cygwin command line before trying to create your project. This is necessary to create certain auto-generated files and directories that will be needed. 3) Set up include pathes: You will need include/, arch/arm/src/sam34, arch/arm/src/common, arch/arm/src/armv7-m, and sched/. 4) All assembly files need to have the definition option -D __ASSEMBLY__ on the command line. Startup files will probably cause you some headaches. The NuttX startup file is arch/arm/src/sam34/sam_vectors.S. You may need to build NuttX one time from the Cygwin command line in order to obtain the pre-built startup object needed by an IDE. NuttX EABI "buildroot" Toolchain ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ A GNU GCC-based toolchain is assumed. The files */setenv.sh should be modified to point to the correct path to the Cortex-M3 GCC toolchain (if different from the default in your PATH variable). If you have no Cortex-M3 toolchain, one can be downloaded from the NuttX Bitbucket download site (https://bitbucket.org/nuttx/buildroot/downloads/). This GNU toolchain builds and executes in the Linux or Cygwin environment. 1. You must have already configured Nuttx in /nuttx. cd tools ./configure.shsam4s-xplained/ 2. Download the latest buildroot package into 3. unpack the buildroot tarball. The resulting directory may have versioning information on it like buildroot-x.y.z. If so, rename /buildroot-x.y.z to /buildroot. 4. cd /buildroot 5. cp configs/cortexm3-eabi-defconfig-4.6.3 .config 6. make oldconfig 7. make 8. Edit setenv.h, if necessary, so that the PATH variable includes the path to the newly built binaries. See the file configs/README.txt in the buildroot source tree. That has more details PLUS some special instructions that you will need to follow if you are building a Cortex-M3 toolchain for Cygwin under Windows. NOTE: Unfortunately, the 4.6.3 EABI toolchain is not compatible with the the NXFLAT tools. See the top-level TODO file (under "Binary loaders") for more information about this problem. If you plan to use NXFLAT, please do not use the GCC 4.6.3 EABI toochain; instead use the GCC 4.3.3 OABI toolchain. See instructions below. NuttX OABI "buildroot" Toolchain ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The older, OABI buildroot toolchain is also available. To use the OABI toolchain: 1. When building the buildroot toolchain, either (1) modify the cortexm3-eabi-defconfig-4.6.3 configuration to use EABI (using 'make menuconfig'), or (2) use an exising OABI configuration such as cortexm3-defconfig-4.3.3 2. Modify the Make.defs file to use the OABI conventions: +CROSSDEV = arm-nuttx-elf- +ARCHCPUFLAGS = -mtune=cortex-m3 -march=armv7-m -mfloat-abi=soft +NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-gotoff.ld -no-check-sections -CROSSDEV = arm-nuttx-eabi- -ARCHCPUFLAGS = -mcpu=cortex-m3 -mthumb -mfloat-abi=soft -NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-pcrel.ld -no-check-sections NXFLAT Toolchain ^^^^^^^^^^^^^^^^ If you are *not* using the NuttX buildroot toolchain and you want to use the NXFLAT tools, then you will still have to build a portion of the buildroot tools -- just the NXFLAT tools. The buildroot with the NXFLAT tools can be downloaded from the NuttX Bitbucket download site (https://bitbucket.org/patacongo/nuttx/downloads/). This GNU toolchain builds and executes in the Linux or Cygwin environment. 1. You must have already configured Nuttx in /nuttx. cd tools ./configure.sh sam4s-xplained/ 2. Download the latest buildroot package into 3. unpack the buildroot tarball. The resulting directory may have versioning information on it like buildroot-x.y.z. If so, rename /buildroot-x.y.z to /buildroot. 4. cd /buildroot 5. cp configs/cortexm3-defconfig-nxflat .config 6. make oldconfig 7. make 8. Edit setenv.h, if necessary, so that the PATH variable includes the path to the newly builtNXFLAT binaries. Buttons and LEDs ^^^^^^^^^^^^^^^^ Buttons ------- The SAM4S Xplained has two mechanical buttons. One button is the RESET button connected to the SAM4S reset line and the other is a generic user configurable button labeled BP2 and connected to GPIO PA5. When a button is pressed it will drive the I/O line to GND. LEDs ---- There are four LEDs on board the SAM4X Xplained board, two of these can be controlled by software in the SAM4S: LED GPIO ---------------- ----- D9 Yellow LED PC10 D10 Yellow LED PC17 Both can be illuminated by driving the GPIO output to ground (low). 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/sam_leds.c. The LEDs are used to encode OS-related events as follows: SYMBOL Meaning LED state D9 D10 ------------------- ----------------------- -------- -------- LED_STARTED NuttX has been started OFF OFF LED_HEAPALLOCATE Heap has been allocated OFF OFF LED_IRQSENABLED Interrupts enabled OFF OFF LED_STACKCREATED Idle stack created ON OFF LED_INIRQ In an interrupt No change LED_SIGNAL In a signal handler No change LED_ASSERTION An assertion failed No change LED_PANIC The system has crashed OFF Blinking LED_IDLE MCU is is sleep mode Not used Thus if D9 is statically on, NuttX has successfully booted and is, apparently, running normmally. If D10 is flashing at approximately 2Hz, then a fatal error has been detected and the system has halted. Serial Consoles ^^^^^^^^^^^^^^^ UART1 ----- If you have a TTL to RS-232 convertor then this is the most convenient serial console to use. UART1 is the default in all of these configurations. UART1 RXD PB2 J1 pin 3 J4 pin 3 UART1 TXD PB3 J1 pin 4 J4 pin 4 GND J1 pin 9 J4 pin 9 Vdd J1 pin 10 J4 pin 10 USART1 ------ USART1 is another option: USART1 RXD PA21 J2 pin 6 USART1 TXD PA22 J2 pin 1 GND J2 pin 9 Vdd J2 pin 10 Virtual COM Port ---------------- Yet another option is to use UART0 and the virtual COM port. This option may be more convenient for long term development, but was painful to use during board bring-up. The SAM4S Xplained contains an Embedded Debugger (EDBG) that can be used to program and debug the ATSAM4S16C using Serial Wire Debug (SWD). The Embedded debugger also include a Virtual Com port interface over USART1. Virtual COM port connections: AT91SAM4S16 ATSAM3U4CAU -------------- -------------- PA9 RX_UART0 PA9_4S PA12 PA10 TX_UART0 RX_3U PA11 SAM4S Xplained-specific Configuration Options ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ CONFIG_ARCH - Identifies the arch/ subdirectory. This should be set to: CONFIG_ARCH=arm CONFIG_ARCH_family - For use in C code: CONFIG_ARCH_ARM=y CONFIG_ARCH_architecture - For use in C code: CONFIG_ARCH_CORTEXM4=y CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory CONFIG_ARCH_CHIP="sam34" CONFIG_ARCH_CHIP_name - For use in C code to identify the exact chip: CONFIG_ARCH_CHIP_SAM34 CONFIG_ARCH_CHIP_SAM4S CONFIG_ARCH_CHIP_ATSAM4S16C CONFIG_ARCH_BOARD - Identifies the configs subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD=sam4s-xplained (for the SAM4S Xplained development board) CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_SAM4S_XPLAINED=y CONFIG_ARCH_LOOPSPERMSEC - Must be calibrated for correct operation of delay loops CONFIG_ENDIAN_BIG - define if big endian (default is little endian) CONFIG_RAM_SIZE - Describes the installed DRAM (SRAM in this case): CONFIG_RAM_SIZE=0x00008000 (32Kb) CONFIG_RAM_START - The start address of installed DRAM CONFIG_RAM_START=0x20000000 CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to boards that have LEDs CONFIG_ARCH_INTERRUPTSTACK - This architecture supports an interrupt stack. If defined, this symbol is the size of the interrupt stack in bytes. If not defined, the user task stacks will be used during interrupt handling. CONFIG_ARCH_STACKDUMP - Do stack dumps after assertions CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to board architecture. CONFIG_ARCH_CALIBRATION - Enables some build in instrumentation that cause a 100 second delay during boot-up. This 100 second delay serves no purpose other than it allows you to calibratre CONFIG_ARCH_LOOPSPERMSEC. You simply use a stop watch to measure the 100 second delay then adjust CONFIG_ARCH_LOOPSPERMSEC until the delay actually is 100 seconds. Individual subsystems can be enabled: CONFIG_SAM34_RTC - Real Time Clock CONFIG_SAM34_RTT - Real Time Timer CONFIG_SAM34_WDT - Watchdog Timer CONFIG_SAM34_UART0 - UART 0 CONFIG_SAM34_UART1 - UART 1 CONFIG_SAM34_SMC - Static Memory Controller CONFIG_SAM34_USART0 - USART 0 CONFIG_SAM34_USART1 - USART 1 CONFIG_SAM34_HSMCI - High Speed Multimedia Card Interface CONFIG_SAM34_TWI0 - Two-Wire Interface 0 CONFIG_SAM34_TWI1 - Two-Wire Interface 1 CONFIG_SAM34_SPI0 - Serial Peripheral Interface CONFIG_SAM34_SSC - Synchronous Serial Controller CONFIG_SAM34_TC0 - Timer Counter 0 CONFIG_SAM34_TC1 - Timer Counter 1 CONFIG_SAM34_TC2 - Timer Counter 2 CONFIG_SAM34_TC3 - Timer Counter 3 CONFIG_SAM34_TC4 - Timer Counter 4 CONFIG_SAM34_TC5 - Timer Counter 5 CONFIG_SAM34_ADC12B - 12-bit Analog To Digital Converter CONFIG_SAM34_DACC - Digital To Analog Converter CONFIG_SAM34_PWM - Pulse Width Modulation CONFIG_SAM34_CRCCU - CRC Calculation Unit CONFIG_SAM34_ACC - Analog Comparator CONFIG_SAM34_UDP - USB Device Port Some subsystems can be configured to operate in different ways. The drivers need to know how to configure the subsystem. CONFIG_SAM34_GPIOA_IRQ CONFIG_SAM34_GPIOB_IRQ CONFIG_SAM34_GPIOC_IRQ CONFIG_USART0_ISUART CONFIG_USART1_ISUART CONFIG_USART2_ISUART CONFIG_USART3_ISUART ST91SAM4S specific device driver settings CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the USARTn (n=0,1,2,3) or UART m (m=4,5) for the console and ttys0 (default is the USART1). CONFIG_U[S]ARTn_RXBUFSIZE - Characters are buffered as received. This specific the size of the receive buffer CONFIG_U[S]ARTn_TXBUFSIZE - Characters are buffered before being sent. This specific the size of the transmit buffer CONFIG_U[S]ARTn_BAUD - The configure BAUD of the UART. Must be CONFIG_U[S]ARTn_BITS - The number of bits. Must be either 7 or 8. CONFIG_U[S]ARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity CONFIG_U[S]ARTn_2STOP - Two stop bits Configurations ^^^^^^^^^^^^^^ Each SAM4S Xplained configuration is maintained in a sub-directory and can be selected as follow: cd tools ./configure.shsam4s-xplained/ cd - . ./setenv.sh Before sourcing the setenv.sh file above, you should examine it and perform edits as necessary so that BUILDROOT_BIN is the correct path to the directory than holds your toolchain binaries. And then build NuttX by simply typing the following. At the conclusion of the make, the nuttx binary will reside in an ELF file called, simply, nuttx. make The that is provided above as an argument to the tools/configure.sh must be is one of the following. NOTES: 1. These configurations use the mconf-based configuration tool. To change any of these configurations using that tool, you should: a. Build and install the kconfig-mconf tool. See nuttx/README.txt see additional README.txt files in the NuttX tools repository. b. Execute 'make menuconfig' in nuttx/ in order to start the reconfiguration process. 2. Unless stated otherwise, all configurations generate console output on UART1 which is available on J1 or J4 (see the section "Serial Consoles" above). USART1 or the virtual COM port on UART0 are options. The virtual COM port could be used, for example, by reconfiguring to use UART0 like: System Type -> AT91SAM3/4 Peripheral Support CONFIG_SAM_UART0=y CONFIG_SAM_UART1=n Device Drivers -> Serial Driver Support -> Serial Console CONFIG_UART0_SERIAL_CONSOLE=y Device Drivers -> Serial Driver Support -> UART0 Configuration CONFIG_UART0_2STOP=0 CONFIG_UART0_BAUD=115200 CONFIG_UART0_BITS=8 CONFIG_UART0_PARITY=0 CONFIG_UART0_RXBUFSIZE=256 CONFIG_UART0_TXBUFSIZE=256 3. Unless otherwise stated, the configurations are setup for Linux (or any other POSIX environment like Cygwin under Windows): Build Setup: CONFIG_HOST_LINUX=y : Linux or other POSIX environment 4. These configurations use the older, OABI, buildroot toolchain. But that is easily reconfigured: System Type -> Toolchain: CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : Buildroot toolchain CONFIG_ARMV7M_OABI_TOOLCHAIN=y : Older, OABI toolchain If you want to use the Atmel GCC toolchain, here are the steps to do so: Build Setup: CONFIG_HOST_WINDOWS=y : Windows CONFIG_HOST_CYGWIN=y : Using Cygwin or other POSIX environment System Type -> Toolchain: CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW=y : General GCC EABI toolchain under windows This re-configuration should be done before making NuttX or else the subsequent 'make' will fail. If you have already attempted building NuttX then you will have to 1) 'make distclean' to remove the old configuration, 2) 'cd tools; ./configure.sh sam3u-ek/ksnh' to start with a fresh configuration, and 3) perform the configuration changes above. Also, make sure that your PATH variable has the new path to your Atmel tools. Try 'which arm-none-eabi-gcc' to make sure that you are selecting the right tool. setenv.sh is available for you to use to set or PATH variable. The path in the that file may not, however, be correct for your installation. See also the "NOTE about Windows native toolchains" in the section call "GNU Toolchain Options" above. Configuration sub-directories ----------------------------- nsh: This configuration directory will built the NuttShell. See NOTES above. NOTES: 1. The configuration configuration can be modified to include support for the on-board SRAM (1MB). System Type -> External Memory Configuration CONFIG_SAM34_EXTSRAM0=y : Select SRAM on CS0 CONFIG_SAM34_EXTSRAM0SIZE=1048576 : Size=1MB Now what are you going to do with the SRAM. There are two choices: a) To enable the NuttX RAM test that may be used to verify the external SRAM: System Type -> External Memory Configuration CONFIG_SAM34_EXTSRAM0HEAP=n : Don't add to heap Application Configuration -> System NSH Add-Ons CONFIG_SYSTEM_RAMTEST=y : Enable the RAM test built-in In this configuration, the SDRAM is not added to heap and so is not excessible to the applications. So the RAM test can be freely executed against the SRAM memory beginning at address 0x6000:0000 (CS0). nsh> ramtest -h Usage: [-w|h|b] Where: starting address of the test. number of memory locations (in bytes). -w Sets the width of a memory location to 32-bits. -h Sets the width of a memory location to 16-bits (default). -b Sets the width of a memory location to 8-bits. To test the entire external SRAM: nsh> ramtest 60000000 1048576 RAMTest: Marching ones: 60000000 1048576 RAMTest: Marching zeroes: 60000000 1048576 RAMTest: Pattern test: 60000000 1048576 55555555 aaaaaaaa RAMTest: Pattern test: 60000000 1048576 66666666 99999999 RAMTest: Pattern test: 60000000 1048576 33333333 cccccccc RAMTest: Address-in-address test: 60000000 1048576 b) To add this RAM to the NuttX heap, you would need to change the configuration as follows: System Type -> External Memory Configuration CONFIG_SAM34_EXTSRAM0HEAP=y : Add external RAM to heap Memory Management -CONFIG_MM_REGIONS=1 : Only the internal SRAM +CONFIG_MM_REGIONS=2 : Also include external SRAM