README ^^^^^^ README for NuttX port to the Stellaris RDK-S2E Reference Design Kit and the MDL-S2E Ethernet to Serial module. Contents ^^^^^^^^ Stellaris RDK-S2E Reference Design Kit Development Environment GNU Toolchain Options IDEs NuttX EABI "buildroot" Toolchain NuttX OABI "buildroot" Toolchain NXFLFAT Toolchain Stellaris MDL-S2E Reference Design Configuration Options Configurations Stellaris RDK-S2E Reference Design Kit ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The Stellaris RDK-S2E Reference Design Kit includes the following features: o MDL-S2E Ethernet to serial module o LM3S6432 in a 10 x 10 mm BGA package for reduced board size o 10/100 Mbit Ethernet port o Auto MDI/MDIX cross-over correction o Traffic and link indicators Serial ports o UART ports include RTS/CTS for flow control o UART0 has RS232 levels, transceiver runs at up to 230.4 Kbaud o UART1 has CMOS/TTL levels, can run at 1.0 Mbaud Features of the LM3S6432 Microcontroller o 32-bit RISC performance using ARM® Cortex™-M3 v7M architecture - 50-MHz operation - Hardware-division and single-cycle-multiplication - Integrated Nested Vectored Interrupt Controller (NVIC) - 42 interrupt channels with eight priority levels o 96 KB single-cycle flash o 32 KB single-cycle SRAM o Three general-purpose 32-bit timers o Integrated Ethernet MAC and PHY o Two fully programmable 16C550-type UARTs o Three 10-bit channels (inputs) when used as single-ended inputs o Two independent integrated analog comparators o One I2C module o One PWM generator block – One 16-bit counter – Two comparators – Produces two independent PWM signals – One dead-band generator o 0 to 43 GPIOs, depending on user configuration o On-chip low drop-out (LDO) voltage regulator GPIO Usage PIN SIGNAL Function --- ----------------- --------------------------------------- L3 PA0/U0RX UART0 receive M3 PA1/U0TX UART0 transmit E12 PB0/U0CTS UART0 CTS D12 PB1/U0RTS UART0 RTS L5 PA4/SPIRX SPI receive (pin hardwired to U1RX) M5 PA5/SPITX SPI transmit (pin hardwired to U1TX) H2 PD2/U1RX UART1 receive H1 PD3/U1TX UART1 transmit L4 PA3/U1CTS/SPICLK UART1 CTS or SPI clock M4 PA2/U1RTS/SPISEL UART1 RTS or SPI slave select J11 PF0/LED1 Ethernet LED1 (green) J12 PF1/LED0 Ethernet LED0 (yellow) C11 PB2 Transciever #INVALID C12 PB3 Transciever #ENABLE A6 PB4 Transciever ON B7 PB5 Transciever #OFF Development Environment ^^^^^^^^^^^^^^^^^^^^^^^ Either Linux, Mac OS X or Cygwin on Windows can be used for the development environment. The source has been built only using the GNU toolchain (see below). Other toolchains will likely cause problems. Testing was performed using GCC on Mac OS X. GNU Toolchain Options ^^^^^^^^^^^^^^^^^^^^^ The NuttX make system has been modified to support the following different toolchain options. 1. The CodeSourcery GNU toolchain, 2. The devkitARM GNU toolchain, 3. The NuttX buildroot Toolchain (see below). To use a specific 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 or on Mac OS X. CONFIG_ARMV7M_TOOLCHAIN_DEVKITARM=y : devkitARM under Windows CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default) 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: the CodeSourcery (for Windows) and devkitARM are Windows native toolchains. The CodeSourcey (for Linux) and NuttX buildroot 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. NOTE 1: The CodeSourcery toolchain (2009q1) does 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/lm, 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/tiva/tiva_vectors.S. 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. This port was tested with tools built using summon-arm-toolchain; available from https://github.com/esden/summon-arm-toolchain, however the buildroot instructions should apply for other platforms. 1. You must have already configured Nuttx in /nuttx. cd tools ./configure.sh lm3s6432-s2e/ 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/nuttx/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 lpcxpresso-lpc1768/ 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. Stellaris MDL-S2E Reference Design 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_CORTEXM3=y CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory CONFIG_ARCH_CHIP=lm CONFIG_ARCH_CHIP_name - For use in C code to identify the exact chip: CONFIG_ARCH_CHIP_LM3S6432 CONFIG_ARCH_BOARD - Identifies the configs subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD=lm3s6432-s2e (for the Stellaris MDL-S2E Reference Design) CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_LM3S6432S2E CONFIG_ARCH_LOOPSPERMSEC - As supplied, calibrated for correct operation of delay loops assuming 50MHz CPU frequency. 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=0x00010000 (64Kb) 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. There are configurations for disabling support for interrupts GPIO ports. GPIOH and GPIOJ must be disabled because they do not exist on the LM3S6432. Additional interrupt support can be disabled if desired to reduce memory footprint - GPIOs C-G are not pinned out on the MDL-S2E board. CONFIG_TIVA_GPIOA_IRQS=y CONFIG_TIVA_GPIOB_IRQS=y CONFIG_TIVA_GPIOC_IRQS=n << Always CONFIG_TIVA_GPIOD_IRQS=n << Always CONFIG_TIVA_GPIOE_IRQS=n << Always CONFIG_TIVA_GPIOF_IRQS=n << Always CONFIG_TIVA_GPIOG_IRQS=n << Always CONFIG_TIVA_GPIOH_IRQS=n << Always CONFIG_TIVA_GPIOJ_IRQS=n << Always LM3S6432 specific device driver settings CONFIG_UARTn_DISABLE The TX and RX pins for UART1 share I/O pins with the TX and RX pins for SSI0. To avoid conflicts, only one of SSI0 and UART1 should be enabled in a configuration. CONFIG_UARTn_SERIAL_CONSOLE - selects the UARTn for the console and ttys0 (default is UART1). CONFIG_UARTn_RXBUFSIZE - Characters are buffered as received. This specific the size of the receive buffer CONFIG_UARTn_TXBUFSIZE - Characters are buffered before being sent. This specific the size of the transmit buffer CONFIG_UARTn_BAUD - The configure BAUD of the UART. Must be CONFIG_UARTn_BITS - The number of bits. Must be either 7 or 8. CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity CONFIG_UARTn_2STOP - Two stop bits CONFIG_TIVA_SSI0 - Select to enable support for SSI0 The TX and RX pins for SSI0 share I/O pins with the TX and RX pins for UART1. To avoid conflicts, only one of SSI0 and UART1 should be enabled in a configuration. CONFIG_TIVA_SSI1 - Select to enable support for SSI1 Note that the LM3S6432 only has one SSI, so SSI1 should always be disabled. CONFIG_SSI_POLLWAIT - Select to disable interrupt driven SSI support. Poll-waiting is recommended if the interrupt rate would be to high in the interrupt driven case. CONFIG_SSI_TXLIMIT - Write this many words to the Tx FIFO before emptying the Rx FIFO. If the SPI frequency is high and this value is large, then larger values of this setting may cause Rx FIFO overrun errors. Default: half of the Tx FIFO size (4). CONFIG_TIVA_ETHERNET - This must be set (along with CONFIG_NET) to build the Stellaris Ethernet driver CONFIG_TIVA_ETHLEDS - Enable to use Ethernet LEDs on the board. CONFIG_TIVA_BOARDMAC - This should be set in order to use the MAC address configured in the flash USER registers. CONFIG_TIVA_ETHHDUPLEX - Set to force half duplex operation CONFIG_TIVA_ETHNOAUTOCRC - Set to suppress auto-CRC generation CONFIG_TIVA_ETHNOPAD - Set to suppress Tx padding CONFIG_TIVA_MULTICAST - Set to enable multicast frames CONFIG_TIVA_PROMISCUOUS - Set to enable promiscuous mode CONFIG_TIVA_BADCRC - Set to enable bad CRC rejection. CONFIG_TIVA_DUMPPACKET - Dump each packet received/sent to the console. Configurations ^^^^^^^^^^^^^^ Each Stellaris MDL-S2E Reference Design configuration is maintained in a sub-directory and can be selected as follow: cd tools ./configure.sh lm3s6432-s2e/ cd - . ./setenv.sh Where is one of the following: nsh: Configures the NuttShell (nsh) located at examples/nsh. The Configuration enables both the serial and telnetd NSH interfaces. NOTE: As it is configured now, you MUST have a network connected. Otherwise, the NSH prompt will not come up because the Ethernet driver is waiting for the network to come up. That is probably a bug in the Ethernet driver behavior!