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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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configs/nsh | ||
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Kconfig | ||
README.txt |
README ^^^^^^ This README discusses issues unique to NuttX configurations for the Atmel SAM4L Xplained Pro development board. This board features the ATSAM4LC4C MCU. The SAM4L Xplained Pro Starter Kit is bundled with four modules: 1) I/O1 - An MMC/SD card slot, PWM LED control, ADC light sensor, UART loopback, TWI AT30TSE758 Temperature sensor. 2) OLED1 - An OLED plus 3 additional switches and 3 additional LEDs 3) SLCD1 - A segment LCD that connects directly to the "EXT5 SEGMENT LCD" connector 4) PROTO1 - A prototyping board with logic on board (other than power-related logic). Contents ^^^^^^^^ - Modules - LEDs - Serial Consoles - SAM4L Xplained Pro-specific Configuration Options - Configurations Modules ^^^^^^^ The SAM4L Xplained Pro Starter Kit is bundled with four modules: I/O1 ---- The primary function of this module is to provide SD card support, but the full list of modules features include: - microSD card connector (SPI interface) - PWM (LED control) - ADC (light sensor) - UART loopback - TWI AT30TSE758 Temperature sensor with EEPROM SPI is available on two of the SAM4L Xplained connectors, EXT1 and EXT2. They mate with the I/O1 connector as indicated in this table. I/O1 Connector -------------- I/O1 EXT1 EXT2 Other use of either pin ----------------- -------------------- -------------------- ------------------------------------ 1 ID 1 1 2 GND 2 GND 2 3 LIGHT_SENSOR 3 PA04 ADCIFE/AD0 3 PA07 ADCIFE/AD2 4 LP_OUT 4 PA05 ADCIFE/AD1 4 PB02 ADCIFE/AD3 5 GPIO1 5 PB12 GPIO 5 PC08 GPIO PB12 and PC8 on EXT5 6 GPIO2 6 PC02 GPIO 6 PB10 GPIO PB10 on EXT5 7 LED 7 PC00 TC/1/A0 7 PC04 TC/1/A2 8 LP_IN 8 PC01 TC/1/B0 8 PC05 TC/1/B2 PC05 on EXT5 9 TEMP_ALERT 9 PC25 EIC/EXTINT2 9 PC06 EIC/EXTINT8 PC25 on EXT5 10 microSD_DETECT 10 PB13 SPI/NPCS1 10 PC09 GPIO PB13 on EXT5 11 TWI SDA 11 PA23 TWIMS/0/TWD 11 PB14 TWIMS/3/TWD PB14 on EXT3&4, PA23 and PB14 on EXT5 12 TWI SCL 12 PA24 TWIMS/0/TWCK 12 PB15 TWIMS/3/TWCK PB15 on EXT3&4, PA24 and PB15 on EXT5 13 UART RX 13 PB00 USART/0/RXD 13 PC26 USART/1/RXD PB00 on EXT4, PC26 on EXT3&5 14 UART TX 14 PB01 USART/0/TXD 14 PC27 USART/1/TXD PB01 on EXT4, PC27 on EXT3&5 15 microSD_SS 15 PC03 SPI/NPCS0 15 PB11 SPI/NPCS2 PB11 on EXT5 16 SPI_MOSI 16 PA22 SPI/MOSI 16 PA22 SPI/MOSI PA22 on EXT5 17 SPI_MISO 17 PA21 SPI/MISO 17 PA21 SPI/MISO PA21 on EXT5 18 SPI_SCK 18 PC30 SPI/SCK 18 PC30 SPI/SCK PC30 on EXT5 19 GND 19 GND GND 20 VCC 20 VCC VCC The mapping between the I/O1 pins and the SD connector are shown in the following table. SD Card Connection ------------------ I/O1 SD PIN Description ---- ---- --- ------------------------------------------------- D2 1 Data line 2 (not used) 15 D3 2 Data line 3. Active low chip select, pulled high 16 CMD 3 Command line, connected to SPI_MOSI. 20 VDD 4 18 CLK 5 Clock line, connected to SPI_SCK. 2/19 GND 6 17 D0 7 Data line 0, connected to SPI_MISO. D1 8 Data line 1 (not used) 10 SW_A 9 Card detect 2/19 SW_B 10 GND Card Detect ----------- When a microSD card is put into the connector SW_A and SW_B are short- circuited. SW_A is connected to the microSD_DETECT signal. To use this as a card indicator remember to enable internal pullup in the target device. GPIOs ----- So all that is required to connect the SD is configure the SPI PIN EXT1 EXT2 Description --- -------------- --------------- ------------------------------------- 15 PC03 SPI/NPCS0 PB11 SPI/NPCS2 Active low chip select OUTPUT, pulled high on board. 10 PB13 SPI/NPCS1 10 PC09 GPIO Active low card detect INPUT, must use internal pull-up. Configuration Options: ---------------------- CONFIG_SAM4L_XPLAINED_IOMODULE=y : Informs the system that the I/O1 module is installed CONFIG_SAM4L_XPLAINED_IOMODULE_EXT1=y : The module is installed in EXT1 CONFIG_SAM4L_XPLAINED_IOMODULE_EXT2=y : The mdoule is installed in EXT2 See the set-up in the discussion of the nsh configuration below for other required configuration options. NOTE: As of this writing, only the SD card slot is supported in the I/O1 module. OLED1 ----- This module provides an OLED plus 3 additional switches and 3 additional LEDs. OLED1 Connector -------------- OLED1 EXT1 EXT2 Other use of either pin ----------------- -------------------- -------------------- ------------------------------------ 1 ID 1 1 2 GND 2 GND 2 3 BUTTON2 3 PA04 ADCIFE/AD0 3 PA07 ADCIFE/AD2 4 BUTTON3 4 PA05 ADCIFE/AD1 4 PB02 ADCIFE/AD3 5 DATA_CMD_SEL 5 PB12 GPIO 5 PC08 GPIO PB12 and PC8 on EXT5 6 LED3 6 PC02 GPIO 6 PB10 GPIO PB10 on EXT5 7 LED1 7 PC00 TC/1/A0 7 PC04 TC/1/A2 8 LED2 8 PC01 TC/1/B0 8 PC05 TC/1/B2 PC05 on EXT5 9 BUTTON1 9 PC25 EIC/EXTINT2 9 PC06 EIC/EXTINT8 PC25 on EXT5 10 DISPLAY_RESET 10 PB13 SPI/NPCS1 10 PC09 GPIO PB13 on EXT5 11 N/C 11 PA23 TWIMS/0/TWD 11 PB14 TWIMS/3/TWD PB14 on EXT3&4, PA23 and PB14 on EXT5 12 N/C 12 PA24 TWIMS/0/TWCK 12 PB15 TWIMS/3/TWCK PB15 on EXT3&4, PA24 and PB15 on EXT5 13 N/C 13 PB00 USART/0/RXD 13 PC26 USART/1/RXD PB00 on EXT4, PC26 on EXT3&5 14 N/C 14 PB01 USART/0/TXD 14 PC27 USART/1/TXD PB01 on EXT4, PC27 on EXT3&5 15 DISPLAY_SS 15 PC03 SPI/NPCS0 15 PB11 SPI/NPCS2 PB11 on EXT5 16 SPI_MOSI 16 PA22 SPI/MOSI 16 PA22 SPI/MOSI PA22 on EXT5 17 N/C 17 PA21 SPI/MISO 17 PA21 SPI/MISO PA21 on EXT5 18 SPI_SCK 18 PC30 SPI/SCK 18 PC30 SPI/SCK PC30 on EXT5 19 GND 19 GND GND 20 VCC 20 VCC VCC Configuration Options: ---------------------- CONFIG_SAM4L_XPLAINED_OLED1MODULE=y : Informs the system that the I/O1 module is installed CONFIG_SAM4L_XPLAINED_OLED1MODULE_EXT1=y : The module is installed in EXT1 CONFIG_SAM4L_XPLAINED_OLED1MODULE_EXT2=y : The mdoule is installed in EXT2 See the set-up in the discussion of the nsh configuration below for other required configuration options. SLCD1 ----- This module provides a A segment LCD that connects directly to the "EXT5 SEGMENT LCD" connector Configuration Options: ---------------------- CONFIG_SAM4L_XPLAINED_SLCD1MODULE=y : Informs the system that the I/O1 module is installed See the set-up in the discussion of the nsh configuration below for other required configuration options. PROTO1 ------ A prototyping board with logic on board (other than power-related logic). There is no built-in support for the PROTO1 module. LEDs ^^^^ There are three LEDs on board the SAM4L Xplained Pro board: The EDBG controls two of the LEDs, a power LED and a status LED. There is only one user controllable LED, a yellow LED labeled LED0 near the SAM4L USB connector. This LED is controlled by PC07 and LED0 can be activated by driving the PC07 to GND. When CONFIG_ARCH_LEDS is defined in the NuttX configuration, NuttX will control LED0 as follows: SYMBOL Meaning LED0 ------------------- ----------------------- ------ LED_STARTED NuttX has been started OFF LED_HEAPALLOCATE Heap has been allocated OFF LED_IRQSENABLED Interrupts enabled OFF LED_STACKCREATED Idle stack created ON LED_INIRQ In an interrupt N/C LED_SIGNAL In a signal handler N/C LED_ASSERTION An assertion failed N/C LED_PANIC The system has crashed FLASH Thus is LED0 is statically on, NuttX has successfully booted and is, apparently, running normmally. If LED0 is flashing at approximately 2Hz, then a fatal error has been detected and the system has halted. Serial Consoles ^^^^^^^^^^^^^^^ USART0 ------ USART0 is available on connectors EXT1 and EXT4 EXT1 EXT4 GPIO Function ---- ---- ------ ----------- 13 13 PB00 USART0_RXD 14 14 PB01 USART0_TXD 19 19 GND 20 20 VCC If you have a TTL to RS-232 converter then this is the most convenient serial console to use. It is the default in all of these configurations. An option is to use the virtual COM port. Virtual COM Port ---------------- The SAM4L Xplained Pro contains an Embedded Debugger (EDBG) that can be used to program and debug the ATSAM4LC4C using Serial Wire Debug (SWD). The Embedded debugger also include a Virtual Com port interface over USART1. Virtual COM port connections: PC26 USART1 RXD PC27 USART1 TXD SAM4L Xplained Pro-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_SAM4L CONFIG_ARCH_CHIP_ATSAM4LC4C CONFIG_ARCH_BOARD - Identifies the boards/ subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD=sam4l-xplained (for the SAM4L Xplained Pro development board) CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_SAM4L_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. Individual subsystems can be enabled: CPU --- CONFIG_SAM34_OCD HSB --- CONFIG_SAM34_APBA CONFIG_SAM34_AESA PBA --- CONFIG_SAM34_IISC CONFIG_SAM34_SPI0 CONFIG_SAM34_TC0 CONFIG_SAM34_TC1 CONFIG_SAM34_TWIM0 CONFIG_SAM34_TWIS0 CONFIG_SAM34_TWIM1 CONFIG_SAM34_TWIS1 CONFIG_SAM34_USART0 CONFIG_SAM34_USART1 CONFIG_SAM34_USART2 CONFIG_SAM34_USART3 CONFIG_SAM34_ADC12B CONFIG_SAM34_DACC CONFIG_SAM34_ACC CONFIG_SAM34_GLOC CONFIG_SAM34_ABDACB CONFIG_SAM34_TRNG CONFIG_SAM34_PARC CONFIG_SAM34_CATB CONFIG_SAM34_TWIM2 CONFIG_SAM34_TWIM3 CONFIG_SAM34_LCDCA PBB --- CONFIG_SAM34_HRAMC1 CONFIG_SAM34_HMATRIX CONFIG_SAM34_PDCA CONFIG_SAM34_CRCCU CONFIG_SAM34_USBC CONFIG_SAM34_PEVC PBC --- CONFIG_SAM34_CHIPID CONFIG_SAM34_FREQM PBD --- CONFIG_SAM34_AST CONFIG_SAM34_WDT CONFIG_SAM34_EIC CONFIG_SAM34_PICOUART 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_SERIALDRIVER CONFIG_USART1_SERIALDRIVER CONFIG_USART2_SERIALDRIVER CONFIG_USART3_SERIALDRIVER ST91SAM4L 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 SAM4L Xplained Pro configuration is maintained in a sub-directory and can be selected as follow: tools/configure.sh sam4l-xplained:<subdir> 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 <subdir> that is provided above as an argument to the tools/configure.sh must be is one of the following. NOTE: 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. 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 of on USART0 which is available on EXT1 or EXT4 (see the section "Serial Consoles" above). The virtual COM port could be used, instead, by reconfiguring to use USART1 instead of USART0: System Type -> AT91SAM3/4 Peripheral Support CONFIG_SAM_USART0=y CONFIG_SAM_USART1=n Device Drivers -> Serial Driver Support -> Serial Console CONFIG_USART0_SERIAL_CONSOLE=y Device Drivers -> Serial Driver Support -> USART0 Configuration CONFIG_USART0_2STOP=0 CONFIG_USART0_BAUD=115200 CONFIG_USART0_BITS=8 CONFIG_USART0_PARITY=0 CONFIG_USART0_RXBUFSIZE=256 CONFIG_USART0_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_ARM_TOOLCHAIN_BUILDROOT=y : Buildroot toolchain CONFIG_ARM_TOOLCHAIN_BUILDROOT_OABI=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_ARM_TOOLCHAIN_GNU_EABI=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) '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. 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 and below: NOTES: 1. NOTE: If you get a compilation error like: libxx_new.cxx:74:40: error: 'operator new' takes type 'size_t' ('unsigned int') as first parameter [-fper Sometimes NuttX and your toolchain will disagree on the underlying type of size_t; sometimes it is an 'unsigned int' and sometimes it is an 'unsigned long int'. If this error occurs, then you may need to toggle the value of CONFIG_ARCH_SIZET_LONG. 2. If the I/O1 module is connected to the SAM4L Xplained Pro, then support for the SD card slot can be enabled by making the following changes to the configuration: File Systems: CONFIG_FS_FAT=y : Enable the FAT file system CONFIG_FAT_LCNAMES=y : Enable upper/lower case 8.3 file names (Optional, see below) CONFIG_FAT_LFN=y : Enable long file named (Optional, see below) CONFIG_FAT_MAXFNAME=32 : Maximum supported file name length There are issues related to patents that Microsoft holds on FAT long file name technologies. See the top level NOTICE file for further details. System Type -> Peripherals: CONFIG_SAM34_SPI0=y : Enable the SAM4L SPI peripheral Device Drivers CONFIG_SPI=y : Enable SPI support CONFIG_SPI_EXCHANGE=y : The exchange() method is supported CONFIG_MMCSD=y : Enable MMC/SD support CONFIG_MMCSD_NSLOTS=1 : Only one MMC/SD card slot CONFIG_MMCSD_MULTIBLOCK_LIMIT=0 : Should not need to disable multi-block transfers CONFIG_MMCSD_HAVE_CARDDETECT=y : I/O1 module as a card detect GPIO CONFIG_MMCSD_SPI=y : Use the SPI interface to the MMC/SD card CONFIG_MMCSD_SPICLOCK=20000000 : This is a guess for the optimal MMC/SD frequency CONFIG_MMCSD_SPIMODE=0 : Mode 0 is required Board Selection -> Common Board Options CONFIG_NSH_MMCSDSLOTNO=0 : Only one MMC/SD slot, slot 0 CONFIG_NSH_MMCSDSPIPORTNO=0 : Use CS=0 if the I/O1 is in EXT1, OR CONFIG_NSH_MMCSDSPIPORTNO=2 : Use CS=2 if the I/O1 is in EXT2 Board Selection -> SAM4L Xplained Pro Modules CONFIG_SAM4L_XPLAINED_IOMODULE=y : I/O1 module is connected CONFIG_SAM4L_XPLAINED_IOMODULE_EXT1=y : In EXT1, or EXT2 CONFIG_SAM4L_XPLAINED_IOMODULE_EXT2=y Application Configuration -> NSH Library CONFIG_NSH_ARCHINIT=y : Board has architecture-specific initialization NOTE: If you enable the I/O1 this configuration with USART0 as the console and with the I/O1 module in EXT1, you *must* remove UART jumper. Otherwise, you have lookpack on USART0 and NSH will *not* behave very well (since its outgoing prompts also appear as incoming commands). STATUS: As of 2013-6-18, this configuration appears completely functional. Testing, however, has been very light. Example: NuttShell (NSH) NuttX-6.28 nsh> mount -t vfat /dev/mmcsd0 /mnt/stuff nsh> ls /mnt/stuff /mnt/stuff: nsh> echo "This is a test" >/mnt/stuff/atest.txt nsh> ls /mnt/stuff /mnt/stuff: atest.txt nsh> cat /mnt/stuff/atest.txt This is a test nsh> 3. If the OLED1 module is connected to the SAM4L Xplained Pro, then support for the OLED display can be enabled by making the following changes to the configuration: System Type -> Peripherals: CONFIG_SAM34_SPI0=y : Enable the SAM4L SPI peripheral Device Drivers -> SPI CONFIG_SPI=y : Enable SPI support CONFIG_SPI_EXCHANGE=y : The exchange() method is supported CONFIG_SPI_CMDDATA=y : CMD/DATA support is required Device Drivers -> LCDs CONFIG_LCD=y : Enable LCD support CONFIG_LCD_MAXCONTRAST=255 : Maximum contrast value CONFIG_LCD_LANDSCAPE=y : Landscape orientation (see below*) CONFIG_LCD_UG2832HSWEG04=y : Enable support for the OLED CONFIG_LCD_SSD1306_SPIMODE=0 : SPI Mode 0 CONFIG_LCD_SSD1306_SPIMODE=3500000 : Pick an SPI frequency Board Selection -> SAM4L Xplained Pro Modules CONFIG_SAM4L_XPLAINED_OLED1MODULE=y : OLED1 module is connected CONFIG_SAM4L_XPLAINED_OLED1MODULE_EXT1=y : In EXT1, or EXT2 CONFIG_SAM4L_XPLAINED_OLED1MODULE_EXT2=y The NX graphics subsystem also needs to be configured: CONFIG_NX=y : Enable graphics support CONFIG_NX_LCDDRIVER=y : Using an LCD driver CONFIG_NX_NPLANES=1 : With a single color plane CONFIG_NX_WRITEONLY=n : You can read from the LCD (see below**) CONFIG_NX_DISABLE_2BPP=y : Disable all resolutions except 1BPP CONFIG_NX_DISABLE_4BPP=y CONFIG_NX_DISABLE_8BPP=y CONFIG_NX_DISABLE_16BPP=y CONFIG_NX_DISABLE_24BPP=y CONFIG_NX_DISABLE_32BPP=y CONFIG_NX_PACKEDMSFIRST=y : LSB packed first (shouldn't matter) CONFIG_NXSTART_EXTERNINIT=y : We have board_graphics_setup() CONFIG_NXTK_BORDERWIDTH=2 : Use a small border CONFIG_NXTK_DEFAULT_BORDERCOLORS=y : Default border colors CONFIG_NXFONTS_CHARBITS=7 : 7-bit fonts CONFIG_NXFONT_SANS17X23B=y : Pick a font (any that will fit) * This orientation will put the buttons "above" the LCD. The reverse landscape configuration (CONFIG_LCD_RLANDSCAPE) will "flip" the display so that the buttons are "below" the LCD. ** The hardware is write only, but the driver maintains a frame buffer to support read and read-write-modiry operations on the LCD. Reading from the frame buffer is, however, untested. Then, in order to use the OLED, you will need to build some kind of graphics application or use one of the NuttX graphics examples. Here, for example, is the setup for the graphic "Hello, World!" example: CONFIG_EXAMPLES_NXHELLO=y : Enables the example CONFIG_EXAMPLES_NXHELLO_DEFAULT_COLORS=y : Use default colors (see below *) CONFIG_EXAMPLES_NXHELLO_DEFAULT_FONT=y : Use the default font CONFIG_EXAMPLES_NXHELLO_BPP=1 : One bit per pixel CONFIG_EXAMPLES_NXHELLO_EXTERNINIT=y : Special initialization is required. * The OLED is monochrome so the only "colors" are black and white. The default "colors" will give you while text on a black background. You can override the faults it you want black text on a while background. NOTE: One issue that I have seen with the NXHello example when running as an NSH command is that it only works the first time. So, after you run the 'nxhello' command one time, you will have to reset the board before you run it again. This is clearly some issue with initializing, un-initializing, and then re-initializing. If you want to fix this, patches are quite welcome. 4. If the LCD1 module is connected to the SAM4L Xplained Pro, then support for the SLCDt can be enabled by making the following changes to the configuration: System Type -> AT91SAM3/4 Peripheral Support CONFIG_SAM34_LCDCA=y System Type -> AT91SAM3/4 Clock Configuration CONFIG_SAM34_OSC32K=y Board Selection -> Board-Specific Options -> SAM4L Xplained Pro Modules CONFIG_SAM4L_XPLAINED_SLCD1MODULE=y Device Drivers CONFIG_LCD=y CONFIG_LCD_MAXCONTRAST=63 Library Routines -> Non-standard Library Support CONFIG_LIBC_SLCDCODEC=y The SLCD example can be enabled to verify the SLCD: Application Configuration -> Examples CONFIG_EXAMPLES_SLCD=y CONFIG_EXAMPLES_SLCD_DEVNAME="/dev/slcd0" CONFIG_EXAMPLES_SLCD_BUFSIZE=64 Application Configuration -> NSH Library CONFIG_NSH_ARCHINIT=y NOTE: In order to use the segment LCD you *must* open the VLCD_A and VLCD_BC jumpers or the SLD will not be powered!