README ^^^^^^ README for NuttX port to the mbed.org LPC1768 board (http://mbed.org/) Contents ^^^^^^^^ Development Environment GNU Toolchain Options IDEs NuttX EABI "buildroot" Toolchain NuttX OABI "buildroot" Toolchain NXFLAT Toolchain USB Device Controller Functions mbed Configuration Options USB Host Configuration Configurations Development Environment ^^^^^^^^^^^^^^^^^^^^^^^ Either Linux 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 the Cygwin environment. 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). All testing has been conducted using the NuttX buildroot toolchain. However, the make system is setup to default to use the devkitARM toolchain. To use the CodeSourcery or devkitARM toolchain, you simply need add one of the following configuration options to your .config (or defconfig) file: CONFIG_LPC17_CODESOURCERYW=y : CodeSourcery under Windows CONFIG_LPC17_CODESOURCERYL=y : CodeSourcery under Linux CONFIG_LPC17_DEVKITARM=y : devkitARM under Windows CONFIG_LPC17_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default) If you are not using CONFIG_LPC17_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. 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: 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 (There is a simple RIDE project in the RIDE subdirectory). 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/lpc17xx, 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/lpc17x/lpc17_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 SourceForge download site (https://sourceforge.net/projects/nuttx/files/buildroot/). 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 mbed/ 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 SourceForge download site (https://sourceforge.net/projects/nuttx/files/). 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. mbed 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=lpc17xx CONFIG_ARCH_CHIP_name - For use in C code to identify the exact chip: CONFIG_ARCH_CHIP_LPC1768=y CONFIG_ARCH_BOARD - Identifies the configs subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD=mbed (for the mbed.org board) CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_MBED=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_DRAM_SIZE - Describes the installed DRAM (CPU SRAM in this case): CONFIG_DRAM_SIZE=(32*1024) (32Kb) There is an additional 32Kb of SRAM in AHB SRAM banks 0 and 1. CONFIG_DRAM_START - The start address of installed DRAM CONFIG_DRAM_START=0x10000000 CONFIG_ARCH_IRQPRIO - The LPC17xx supports interrupt prioritization CONFIG_ARCH_IRQPRIO=y 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_LPC17_MAINOSC=y CONFIG_LPC17_PLL0=y CONFIG_LPC17_PLL1=n CONFIG_LPC17_ETHERNET=n CONFIG_LPC17_USBHOST=n CONFIG_LPC17_USBOTG=n CONFIG_LPC17_USBDEV=n CONFIG_LPC17_UART0=y CONFIG_LPC17_UART1=n CONFIG_LPC17_UART2=n CONFIG_LPC17_UART3=n CONFIG_LPC17_CAN1=n CONFIG_LPC17_CAN2=n CONFIG_LPC17_SPI=n CONFIG_LPC17_SSP0=n CONFIG_LPC17_SSP1=n CONFIG_LPC17_I2C0=n CONFIG_LPC17_I2C1=n CONFIG_LPC17_I2S=n CONFIG_LPC17_TMR0=n CONFIG_LPC17_TMR1=n CONFIG_LPC17_TMR2=n CONFIG_LPC17_TMR3=n CONFIG_LPC17_RIT=n CONFIG_LPC17_PWM0=n CONFIG_LPC17_MCPWM=n CONFIG_LPC17_QEI=n CONFIG_LPC17_RTC=n CONFIG_LPC17_WDT=n CONFIG_LPC17_ADC=n CONFIG_LPC17_DAC=n CONFIG_LPC17_GPDMA=n CONFIG_LPC17_FLASH=n LPC17xx specific device driver settings CONFIG_UARTn_SERIAL_CONSOLE - selects the UARTn for the console and ttys0 (default is the UART0). 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 LPC17xx specific CAN device driver settings. These settings all require CONFIG_CAN: CONFIG_CAN_EXTID - Enables support for the 29-bit extended ID. Default Standard 11-bit IDs. CONFIG_CAN1_BAUD - CAN1 BAUD rate. Required if CONFIG_LPC17_CAN1 is defined. CONFIG_CAN2_BAUD - CAN1 BAUD rate. Required if CONFIG_LPC17_CAN2 is defined. CONFIG_CAN1_DIVISOR - CAN1 is clocked at CCLK divided by this number. (the CCLK frequency is divided by this number to get the CAN clock). Options = {1,2,4,6}. Default: 4. CONFIG_CAN2_DIVISOR - CAN2 is clocked at CCLK divided by this number. (the CCLK frequency is divided by this number to get the CAN clock). Options = {1,2,4,6}. Default: 4. CONFIG_CAN_TSEG1 - The number of CAN time quanta in segment 1. Default: 6 CONFIG_CAN_TSEG2 = the number of CAN time quanta in segment 2. Default: 7 LPC17xx specific PHY/Ethernet device driver settings. These setting also require CONFIG_NET and CONFIG_LPC17_ETHERNET. CONFIG_PHY_KS8721 - Selects Micrel KS8721 PHY CONFIG_PHY_AUTONEG - Enable auto-negotion CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed. CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18 CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18 CONFIG_NET_PRIORITY - Ethernet interrupt priority. The is default is the higest priority. CONFIG_NET_WOL - Enable Wake-up on Lan (not fully implemented). CONFIG_NET_REGDEBUG - Enabled low level register debug. Also needs CONFIG_DEBUG. CONFIG_NET_DUMPPACKET - Dump all received and transmitted packets. Also needs CONFIG_DEBUG. CONFIG_NET_HASH - Enable receipt of near-perfect match frames. CONFIG_NET_MULTICAST - Enable receipt of multicast (and unicast) frames. Automatically set if CONFIG_NET_IGMP is selected. LPC17xx USB Device Configuration CONFIG_LPC17_USBDEV_FRAME_INTERRUPT Handle USB Start-Of-Frame events. Enable reading SOF from interrupt handler vs. simply reading on demand. Probably a bad idea... Unless there is some issue with sampling the SOF from hardware asynchronously. CONFIG_LPC17_USBDEV_EPFAST_INTERRUPT Enable high priority interrupts. I have no idea why you might want to do that CONFIG_LPC17_USBDEV_NDMADESCRIPTORS Number of DMA descriptors to allocate in SRAM. CONFIG_LPC17_USBDEV_DMA Enable lpc17xx-specific DMA support CONFIG_LPC17_USBDEV_NOVBUS Define if the hardware implementation does not support the VBUS signal CONFIG_LPC17_USBDEV_NOLED Define if the hardware implementation does not support the LED output LPC17xx USB Host Configuration CONFIG_USBHOST_OHCIRAM_SIZE Total size of OHCI RAM (in AHB SRAM Bank 1) CONFIG_USBHOST_NEDS Number of endpoint descriptors CONFIG_USBHOST_NTDS Number of transfer descriptors CONFIG_USBHOST_TDBUFFERS Number of transfer descriptor buffers CONFIG_USBHOST_TDBUFSIZE Size of one transfer descriptor buffer CONFIG_USBHOST_IOBUFSIZE Size of one end-user I/O buffer. This can be zero if the application can guarantee that all end-user I/O buffers reside in AHB SRAM. USB Host Configuration ^^^^^^^^^^^^^^^^^^^^^^ The mbed board can be easily modified to support a USB host interface (Remember to add 2 resistors of 15K to D+ and D- pins). The hidkbd configuration assumes that this change has been made. The NuttShell (NSH) mbed can also be modified in order to support USB host operations. To make these modifications, do the following: 1. First configure to build the NSH configuration from the top-level NuttX directory: cd tools ./configure mbed/nsh cd .. 2. Then edit the top-level .config file to enable USB host. Make the following changes: CONFIG_LPC17_USBHOST=y CONFIG_USBHOST=y CONFIG_SCHED_WORKQUEUE=y When this change is made, NSH should be extended to support USB flash devices. When a FLASH device is inserted, you should see a device appear in the /dev (pseudo) directory. The device name should be like /dev/sda, /dev/sdb, etc. The USB mass storage device, is present it can be mounted from the NSH command line like: ls /dev mount -t vfat /dev/sda /mnt/flash Files on the connect USB flash device should then be accessible under the mountpoint /mnt/flash. Configurations ^^^^^^^^^^^^^^ Each mbed configuration is maintained in a sub-directory and can be selected as follow: cd tools ./configure.sh mbed/ cd - . ./setenv.sh Where is one of the following: hidkbd: This configuration directory, performs a simple test of the USB host HID keyboard class driver using the test logic in examples/hidkbd. This configuration assumes that you have modified your mbed for USB host support. nsh: Configures the NuttShell (nsh) located at examples/nsh. The Configuration enables only the serial NSH interfaces. See notes above for enabling USB host support in this configuration.