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replace *(.init_array .init_array.*) with KEEP(*(.init_array .init_array.*)). The KEEP statement within a linker script will instruct the linker to keep the specified section, even if no symbols inside it are referenced. This statement is used within the SECTIONS section of the linker script. This becomes relevant when garbage collection is performed at link time, enabled by passing the --gc-sections switch to the linker. The KEEP statement instructs the linker to use the specified section as a root node when creating a dependency graph, looking for unused sections. Essentially forcing the section to be marked as used. Signed-off-by: cuiziwei <cuiziwei@xiaomi.com> |
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lpc21isp-1.60.diff | ||
README.txt |
README ^^^^^^ This README discusses issues unique to NuttX configurations for the MCU-123 LPC2148 development board. Contents -------- o Development Environment o GNU Toolchain Options o NuttX buildroot Toolchain o Flash Tools - In System Programming (ISP) Mode - LPC21ISP (Linux) - FlashMagic (Windows/MAC) - OpenOCD o ARM/LPC214X-specific Configuration Options o 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. GNU Toolchain Options ^^^^^^^^^^^^^^^^^^^^^ The NuttX make system has been modified to support the following different toolchain options. 1. The NuttX buildroot Toolchain (see below), or 2. The GNU EABI toolchain, All testing has been conducted using the NuttX buildroot toolchain. To use the CodeSourcery or devkitARM GNU toolchain, you simply need to build the system as follows: make # Will build for the NuttX buildroot toolchain make CROSSDEV=arm-eabi- # Will build for the devkitARM toolchain make CROSSDEV=arm-none-eabi- # Will build for the ARM EABI toolchain make CROSSDEV=arm-nuttx-elf- # Will build for the NuttX buildroot toolchain Of course, hard coding this CROSS_COMPILE value in Make.defs file will save some repetitive typing. NuttX buildroot Toolchain ^^^^^^^^^^^^^^^^^^^^^^^^^ A GNU GCC-based toolchain is assumed. The PATH environment variable 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 <some-dir>/nuttx. tools/configure.sh eagle100:<sub-dir> 2. Download the latest buildroot package into <some-dir> 3. unpack the buildroot tarball. The resulting directory may have versioning information on it like buildroot-x.y.z. If so, rename <some-dir>/buildroot-x.y.z to <some-dir>/buildroot. 4. cd <some-dir>/buildroot 5. cp boards/arm7tdmi-defconfig-4.3.3 .config 6. make oldconfig 7. make 8. Make sure that the PATH variable includes the path to the newly built binaries. See the file boards/README.txt in the buildroot source tree. That has more detailed PLUS some special instructions that you will need to follow if you are building a Cortex-M3 toolchain for Cygwin under Windows. Flash Tools ^^^^^^^^^^^ In System Programming (ISP) Mode -------------------------------- 1. Make sure you exit minicom (or whatever terminal emulator you are using). It will interfere with the download. 2. On the MCU123 board, I need to put a jumper on JP3-INT. On that board, JP3-INT is connected to P0.14 of LPC214x. When P0.14 is low and RTS is changed from high to low, the LPC214x will enter ISP (In System Programming) state. J2-RST: When J2 is shorted, the reset pin of CPU is controlled by the DTR signal of UART0. Short J2 to enable ISP automatic download. Alternatively, you can just press the INT1 button while resetting. The LEDs will be off if the LPC2148 successfully enters ISP mode. Resetting the board will enter ISP mode when the jumper is connected. LPC21ISP (Linux) ---------------- (ca. 2008) I use the lpc21isp tool to load NuttX into FLASH. In the older version 1.60 of lpc21isp for Linux, I had to make several changes. This changesi are shown in lpc21ips-1.60.diff. I use the script lpc21isp.sh to perform the actual download. You will probably have to make some changes to this script in order to use it. For example, the path to the built lpc21isp binary will most likely have to change. Then move this script to the top level NuttX directory and simply execute it to load NuttX onto the board (after entering ISP mode). Here are the detailed steps I use: 1. Setup ISP (In System Programming) mode (see above). 3. Start lpc21isp.sh 4. Reset the board to FlashMagic (Windows/MAC) ------------------------ (ca. 2012) You download FlashMagic for Windows or MAC here: http://www.flashmagictool.com 1. Setup ISP (In System Programming) mode (see above). 2. Start FlashMagic and setup communication parameters. Device: LPC2148 COM Port: (will vary with PC) Baud: 38400 (I am sure it can go faster). Interface: None (ISP) Oscillator (MHz): 12 Check "Erase all Flash+Code Rd Prot" 3. Select the nuttx.hex file 4. Options: Verify after programming 5. Start and reset the board to entry ISP mode. Or hold the INT1 button down after reset after you press start. NOTE: FlashMagic will complain if the data section overlaps 0x4000000-0x400001ff. OpenOCD ------- I have the (really old) Olimex software installed at C:/gccfd. Under Cygwin, I can do the following: 1. Create a .cfg file: $ cat /cygdrive/c/gccfd/openocd/lib/openocd/interface/arm-usb-ocd.cfg /cygdrive/c/gccfd/openocd/lib/openocd/target/lpc2148.cfg > lpc2148.cfg 2. Start OpenOCD: /cygdrive/c/gccfd/openocd/bin/openocd-ftd2xx.exe -f lpc2148.cfg -s . & 3. Start arm-*-gdb (whichever GDB your toolchain uses). ARM/LPC214X-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_ARM7TDMI=y CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory CONFIG_ARCH_CHIP=lpc214x CONFIG_ARCH_CHIP_name - For use in C code CONFIG_ARCH_CHIP_LPC214X CONFIG_ARCH_BOARD - Identifies the boards/ subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD=mcu123-lpc214x CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_MCU123_LPC214X (for theMCU123 LPC214x board) 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 RAM. CONFIG_RAM_START - The start address of installed RAM 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 LPC2148 specific chip initialization These provide register setup values: CONFIG_EXTMEM_MODE, CONFIG_RAM_MODE, CONFIG_CODE_BASE, CONFIG_PLL_SETUP, CONFIG_MAM_SETUP, CONFIG_APBDIV_SETUP, CONFIG_EMC_SETUP, CONFIG_BCFG0_SETUP, CONFIG_BCFG1_SETUP, CONFIG_BCFG2_SETUP, CONFIG_BCFG3_SETUP, CONFIG_ADC_SETUP CONFIG_LPC214x_FIO - Enable fast GPIO (vs. legacy, "old" GPIO). LPC214X 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. 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, 3=mark 1, 4=space 0 CONFIG_UARTn_2STOP - Two stop bits LPC214X USB Configuration CONFIG_LPC214X_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_LPC214X_USBDEV_EPFAST_INTERRUPT Enable high priority interrupts. I have no idea why you might want to do that CONFIG_LPC214X_USBDEV_NDMADESCRIPTORS Number of DMA descriptors to allocate in the 8Kb USB RAM. This is a tradeoff between the number of DMA channels that can be supported vs the size of the DMA buffers available. CONFIG_LPC214X_USBDEV_DMA Enable lpc214x-specific DMA support Configurations ^^^^^^^^^^^^^^ 1. Each NXP LPC214x configuration is maintained in a sub-directory and can be selected as follow: tools/configure.sh mcu123-lpc214x:<subdir> Where <subdir> is one of the configuration sub-directories described in the following paragraph. 2. These configurations use the mconf-based configuration tool. To change a 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. 3. By default, all configurations assume the NuttX Buildroot toolchain under Linux (should work under Windows with Cygwin as well). This is easily reconfigured: CONFIG_HOST_LINUX=y CONFIG_ARM_TOOLCHAIN_BUILDROOT=y composite: ---------- A simple test of the USB Composite Device (see apps/examples/README.txt and apps/system/composite) NOTE: I could not get this to work! Perhaps this is a consequence of the last USB driver checking (r4359). But backing this change out did not fix the configuration. nsh: ---- Configures the NuttShell (nsh) located at examples/nsh. The Configuration enables only the serial NSH interfaces. usbserial: ---------- This configuration directory exercises the USB serial class driver at examples/usbserial. See examples/README.txt for more information. NOTE: If you have problems with this configuration, perhaps it is a consequence of the last USB driver checking (r4359) usbmsc: ------- This configuration directory exercises the USB mass storage class driver at system/usbmsc. See examples/README.txt for more information. NOTE: If you have problems with this configuration, perhaps it is a consequence of the last USB driver checking (r4359)