README.txt ========== This is the README file for the port of NuttX to the Freescale Freedom KL26Z board. This board has the MKL26Z128 chip with a built-in SDA debugger. Contents ======== - Development Environment - GNU Toolchain Options - NuttX Buildroot Toolchain - LEDs - Serial Console - mbed - Freedom KL26Z-specific Configuration Options - Configurations Development Environment ======================= Either Linux or Cygwin under 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 ===================== As of this writing, all testing has been performed using the NuttX buildroot toolchain described below. I have also verified the build using the CodeSourcery GCC toolchain for windows. Most any contemporary EABI GCC toolchain should work will a little tinkering. 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-M0 GCC toolchain (if different from the default in your PATH variable). If you have no Cortex-M0 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 /nuttx. tools/configure.sh freedom-kl26z: 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 boards/cortexm0-eabi-defconfig-4.6.3 .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 details PLUS some special instructions that you will need to follow if you are building a Cortex-M0 toolchain for Cygwin under Windows. LEDs ==== The Freedom KL26Z has a single RGB LED driven by the KL26Z as follows: ------------- -------- RGB LED KL26Z128 ------------- -------- Red Cathode PTE29 Green Cathode PTE31 Blue Cathode PTD5 NOTE: PTD5 is also connected to the I/O header on J2 pin 12 (also known as D13). If CONFIG_ARCH_LEDs is defined, then NuttX will control the LED on board the Freedom KL26Z. The following definitions describe how NuttX controls the LEDs: SYMBOL Meaning LED state Initially all LED is OFF ------------------- ----------------------- -------------------------- LED_STARTED NuttX has been started R=OFF G=OFF B=OFF LED_HEAPALLOCATE Heap has been allocated (no change) LED_IRQSENABLED Interrupts enabled (no change) LED_STACKCREATED Idle stack created R=OFF G=OFF B=ON LED_INIRQ In an interrupt (no change) LED_SIGNAL In a signal handler (no change) LED_ASSERTION An assertion failed (no change) LED_PANIC The system has crashed R=FLASHING G=OFF B=OFF LED_IDLE K26Z1XX is in sleep mode (Optional, not used) Serial Console ============== As with most NuttX configurations, the Freedom KL26Z configurations depend on having a serial console to interact with the software. The Freedom KL26Z, however, has no on-board RS-232 drivers so will be necessary to connect the Freedom KL26Z UART pins to an external RS-232 driver board or TTL-to-Serial USB adaptor. By default UART0 is used as the serial console on this boards. The UART0 is configured to work with the OpenSDA USB CDC/ACM port: ------ ------------------------------- ----------------------------- PIN PIN FUNCTIONS BOARD SIGNALS ------ ------------------------------- ----------------------------- Pin 27 PTA1/TSI0_CH2/UART0_RX/FTM2_CH0 UART1_RX_TGTMCU and D0 (PTA1) Pin 28 PTA2/TSI0_CH3/UART0_TX/FTM2_CH1 UART1_TX_TGTMCU and D1 (PTA2) But the UART0 Tx/Rx signals are also available on J1: ---------------- --------- UART0 SIGNAL J1 pin ---------------- --------- UART0_RX (PTA1) J1, pin 2 UART0_TX (PTA2) J1, pin 4 Ground is available on J2 pin 14. 3.3V is available on J3 and J4. Freedom KL26Z-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_CORTEXM0=y CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory CONFIG_ARCH_CHIP=kl CONFIG_ARCH_CHIP_name - For use in C code to identify the exact chip: CONFIG_ARCH_CHIP_MKL26Z128=y CONFIG_ARCH_BOARD - Identifies the boards/ subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD=freedom-kl26z (for the Freescale FRDM-KL26Z development board) CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_FREEDOM_K26Z128=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=16384 (16Kb) 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 as follows. These settings are for all of the K25Z100/120 line and may not be available for the MKL26Z128 in particular: AHB --- CONFIG_KL_PDMA Peripheral DMA CONFIG_KL_FMC Flash memory CONFIG_KL_EBI External bus interface APB1 ---- CONFIG_KL_WDT Watchdog timer CONFIG_KL_RTC Real time clock (RTC) CONFIG_KL_TMR0 Timer0 CONFIG_KL_TMR1 Timer1 CONFIG_KL_I2C0 I2C interface CONFIG_KL_SPI0 SPI0 master/slave CONFIG_KL_SPI1 SPI1 master/slave CONFIG_KL_PWM0 PWM0 CONFIG_KL_PWM1 PWM1 CONFIG_KL_PWM2 PWM2 CONFIG_KL_PWM3 PWM3 CONFIG_KL_UART0 UART0 CONFIG_KL_USBD USB 2.0 FS device controller CONFIG_KL_ACMP Analog comparator CONFIG_KL_ADC Analog-digital-converter (ADC) APB2 --- CONFIG_KL_PS2 PS/2 interface CONFIG_KL_TIMR2 Timer2 CONFIG_KL_TIMR3 Timer3 CONFIG_KL_I2C1 I2C1 interface CONFIG_KL_SPI2 SPI2 master/slave CONFIG_KL_SPI3 SPI3 master/slave CONFIG_KL_PWM4 PWM4 CONFIG_KL_PWM5 PWM5 CONFIG_KL_PWM6 PWM6 CONFIG_KL_PWM7 PWM7 CONFIG_KL_UART1 UART1 CONFIG_KL_UART2 UART2 CONFIG_KL_I2S I2S interface K26Z1XX specific device driver settings CONFIG_UARTn_SERIAL_CONSOLE - Selects the UARTn (n=0,1,2) for the console and ttys0. CONFIG_UARTn_RXBUFSIZE - Characters are buffered as received. This specific the size of the receive buffer for UARTn. CONFIG_UARTn_TXBUFSIZE - Characters are buffered before being sent. This specific the size of the transmit buffer for UARTn. CONFIG_UARTn_BAUD - The configure BAUD of UARTn, CONFIG_UARTn_BITS - The number of bits. Must be 5, 6, 7, or 8. CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity CONFIG_UARTn_2STOP - Two stop bits Configurations ============== Each FREEDOM-KL26Z configuration is maintained in a sub-directory and can be selected as follow: tools/configure.sh freedom-kl26z: If this is a Windows native build, then configure.bat should be used instead of configure.sh: configure.bat freedom-kl26z\ Where is one of the following: nsh: --- Configures the NuttShell (nsh) located at apps/examples/nsh. The Configuration enables the serial interface on UART0. Support for builtin applications is disabled. NOTES: 1. This configuration uses the mconf-based configuration tool. To change this configuration 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. By default, this configuration uses the ARM EABI toolchain for Windows and builds under Cygwin (or probably MSYS). That can easily be reconfigured, of course. CONFIG_HOST_WINDOWS=y : Builds under Windows CONFIG_WINDOWS_CYGWIN=y : Using Cygwin CONFIG_ARMV7M_TOOLCHAIN_GNU_EABI=y : GNU EABI toolchain for Windows 3. Serial Console. A serial console is necessary to interrupt with NSH. The serial console is configured on UART0 which is available on J1: ---------------- --------- UART0 SIGNAL J1 pin ---------------- --------- UART0_RX (PTA1) J1, pin 2 UART0_TX (PTA2) J1, pin 4 Ground is available on J2 pin 14. 3.3V is available on J3 and J4. It is possible to configure NSH to use a USB serial console instead of an RS-232 serial console. However, that configuration has not been impelmented as of this writing. 4. Memory Usage. The size command gives us the static memory usage. This is what I get: $ size nuttx text data bss dec hex filename 35037 106 1092 36235 8d8b nuttx And we can get the runtime memory usage from the NSH free command: NuttShell (NSH) NuttX-6.25 nsh> free total used free largest Mem: 14160 3944 10216 10216 nsh> Summary: - This slightly tuned NSH example uses 34.2KB of FLASH leaving 93.8KB of FLASH (72%) free from additional application development. I did not do all of the arithmetic, but it appears to me that of this 34+KB of FLASH usage, probably 20-30% of the FLASH is used by libgcc! libgcc has gotten very fat! - Static SRAM usage is about 1.2KB (<4%). - At run time, 10.0KB of SRAM (62%) is still available for additional applications. Most of the memory used at runtime is allocated I/O buffers and the stack for the NSH main thread (1.5KB). There is probably enough free memory to support 3 or 4 application threads in addition to NSH. 5. This configurations has support for NSH built-in applications. However, in the default configuration no built-in applications are enabled.