================ beaglebone-black ================ This directory contains the port of NuttX to the Beaglebone Black board See http://beagleboard.org for information about Beaglebone Black. This board is based around the TI AM335x Sitara Cortex-A8 CPU. This port was developed on the rev. C of the board: Beaglebone Black (See http://beagleboard.org/black) Main features of the TI AM335x Sitara (See http://www.ti.com/product/am3358): =================== ============================================================= ITEMS DETAILS =================== ============================================================= CPU 1GHz ARM Cortex-A8 FPU NEON SIMD Coprocessor I-Cache 32KB D-Cache 32KB L2 Cache 256KB L2 Cache with ECC GPU SG530 3D, 20M Polygons/S DRAM 512MB DDR3 800MHz On-Chip SRAM 64KB Dedicated SRAM 64KB On-Chip Boot ROM 176KB Onboard Storage 4GB, 8bit Embedded MMC, microSD card (TF) slot for up to 32GB Video Output HDMI Extension Interface 2.54mm Headers, 92 pins Network interface 10/100Mbps RJ45 Power 5V, 1000mA Overall Size 3.4" X 2.15" =================== ============================================================= Boot Devices: * SD Card * eMMC * UART Contents ======== - Beaglebone black Rev.C Connectors - Serial Console - LEDs - Buttons - JTAG - Booting NuttX from an SD card - Configurations Beaglebone black Rev.C Connectors ================================= Serial Console ============== By default, the serial console will be provided on UART0 in all of these configurations. UART0 is available on the 6-pin Debug connector: * Pin 1: GND * Pin 2: N/C * Pin 3: N/C * Pin 4: B_UART0_RX / UART0_RX / PIN E15 * Pin 5: B_UART0_TX / UART0_TX / PIN E16 * Pin 6: N/C ======== ======================================================= Pin Alternate Function ======== ======================================================= PIN E16 UART0_TXD/SPI1_CS1/DCAN0_RX/I2C2_SCL/ECAP1_IN_PWM1_OUT/ PR1_PRU1_PRU_R30_15/PR1_PRU1_PRU_R31_15/GPIO1_11 PIN E15 UART0_RXD/SPI1_CS0/DCAN0_TX/I2C2_SDA/ECAP2_IN_PWM2_OUT/ PR1_PRU1_PRU_R30_14/PR1_PRU1_PRU_R31_14/GPIO1_10 ======== ======================================================= LEDs ==== The Beaglebone black Rev. C has four blue LEDs; three can be controlled from software. Two are tied to ground and, hence, illuminated by driving the output pins to a high value: ==== ======== ===================================================== LED PIN Pin alternate functions ? ==== ======== ===================================================== LED0 GPIO1_21 GPMC_A5/GMII2_TXD0/RGMII2_TD0/RMII2_TXD0/GPMC_A21/ PR1_MII1_RXD3/eQEP1B_IN/GPIO1_21 LED1 GPIO1_22 GPMC_A6/GMII2_TXCLK/RGMII2_TCLK/MMC2_DAT4/GPMC_A22/ PR1_MII1_RXD2/eQEP1_INDEX/GPIO1_22 LED2 GPIO1_23 GPMC_A7/GMII2_RXCLK/RGMII2_RCLK/MMC2_DAT5/GPMC_A23/ PR1_MII1_RXD1/eQEP1_STROBE/GPIO1_23 LED3 GPIO1_24 GPMC_A8/GMII2_RXD3/RGMII2_RD3/MMC2_DAT6/GPMC_A24/ PR1_MII1_RXD0/MCASP0_ACLKX/GPIO1_24 ==== ======== ===================================================== 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/am335x_leds.c. The LEDs are used to encode OS-related events as follows: ================= ======================= ======== ======== ============ SYMBOL Meaning LED1 LED3 LED4 ================= ======================= ======== ======== ============ LED_STARTED NuttX has been started ON OFF OFF LED_HEAPALLOCATE Heap has been allocated OFF ON OFF LED_IRQSENABLED Interrupts enabled ON ON OFF LED_STACKCREATED Idle stack created ON ON OFF LED_INIRQ In an interrupt N/C N/C Soft glow LED_SIGNAL In a signal handler N/C N/C Soft glow LED_ASSERTION An assertion failed N/C N/C Soft glow LED_PANIC The system has crashed N/C N/C 2Hz Flashing LED_IDLE MCU is is sleep mode Not used Not used Not used ================= ======================= ======== ======== ============ After booting, LED1 and 3 are not longer used by the system and can be used for other purposes by the application (Of course, all LEDs are available to the application if CONFIG_ARCH_LEDS is not defined. Buttons ======= JTAG ==== Booting NuttX from an SD card ============================= These are the steps to get U-Boot booting from SD Card: #. Configure and build the NuttX Beaglebone Black configuration. You should have a file called nuttx.bin when the build completes. #. Insert a FLASH stick into the host PC and format it for FAT32 FS. #. Copy nuttx.bin into FLASH stick root. #. Remove the FLASH stick from the host PC. Insert into the Beaglebone Black microSD slot. #. Connect a RS-232 Converted or USB serial adapter onto the Beaglebone Black board and open a serial terminal on the host PC to communicate with the target. #. Reset the Stop Beaglebone Black boot. You should see output from U-boot in the serial console. Stop the normal boot-up sequence after the U-Boot prompt before Linux is started.: *Hit any key to stop autoboot: 0* *U-Boot#* #. Load NuttX into memory from the U-Boot prompt and run *U-Boot# load mmc 0 0x8a000000 nuttx.bin* *U-Boot# go 0x8a000000* If your are running the 'nsh' configuration you then should see: *NuttShell (NSH)* *nsh>* Configurations ============== Information Common to All Configurations ---------------------------------------- Each Beaglebone Black configuration is maintained in a sub-directory and can be selected as follow: *tools/configure.sh [OPTIONS] beaglebone-black:* Where [OPTIONS] include -l to configure for a Linux host platform and -c means to configure for a Windows Cygwin host platform. -h will give you the list of all options. Before building, make sure the PATH environment variable includes 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 * These configurations use the mconf-based configuration tool. To change any of these configurations using that tool, you should: * Build and install the kconfig-mconf tool. See nuttx/README.txt see additional README.txt files in the NuttX tools repository. * Execute *make menuconfig* in nuttx/ in order to start the reconfiguration process. * Unless stated otherwise, all configurations generate console output on UART0. * All of these configurations use the Code Sourcery for Windows toolchain (unless stated otherwise in the description of the configuration). That toolchain selection can easily be reconfigured using 'make menuconfig'. Here are the relevant current settings: Build Setup: CONFIG_HOST_WINDOWS=y : Microsoft Windows CONFIG_WINDOWS_CYGWIN=y : Using Cygwin or other POSIX environment System Type -> Toolchain: CONFIG_ARM_TOOLCHAIN_GNU_EABI=y : GNU EABI toolchain Configuration Sub-directories ----------------------------- lcd: This is an NSH configuration based on the nsh configuration belong but with LCD support enabled. This configuration will be used for developing and verifying basic LCD functionality. NOTES: #. The framebuffer is assumed to reside at address 0x80000000 and has a maximum size 0x0a000000, although probably less than 1Mb will actually be used for the framebuffer. #. The HDMI interface is assumed. The TDA19988 HDMI interface is enabled. STATUS: 2019-07-09: This is very much a work in progress and not suitable for any use other than testing. nsh: This configuration directory provides the NuttShell (NSH). STATUS: 2019-01-06: Work in progress. Till now it is possible to pass arm_boot(), but Prefetch abort is met when devnull_register() call is done. Have no idea why. I was able to trace down to _inode_search() call. If I put any debug statement like "arm_lowputc('0');" right after "desc->node = node;" statement at line 425 the code does not crash. 2019-01-09: The NSH configuration is now functional. 2019-01-16: Correct timer interrupts by switching to DMTimer2 (DMTimer1ms is not initialized by U-Boot).