README
^^^^^^
This is the README file for the NuttX port to the Atmel AVR32DEV1 board.
Contents
^^^^^^^^
* Pin Configuration
* Serial Connection
* Toolchains
* Development Environment
* GNU Toolchains
* IDEs
* AVR32 Bootloader
* AVR32DEV1 Configuration Options
* Configurations
Pin Configuration
^^^^^^^^^^^^^^^^^
The only GPIO pin usage is for LEDs (2) and Buttons (2):
PIN 13 PA7 LED1
PIN 14 PA8 LED2
PIN 24 PB2 KEY1
PIN 25 PB3 KEY2
See configs/avr32dev/src/avr32dev_internal.h
Serial Connection
^^^^^^^^^^^^^^^^^
USART1 is the default USART1 used in the configuration files to
provide a serial console (of course, that can be easily changed
by editting the configuration file). The AVR32DEV1 board has no
RS-232 drivers or connectors on board. I use an off-board MAX232
module that I got on eBay (search for MAX232 if you want to find
one). I connect the MAX232 board as follows:
In configs/avr32dev/include/board.h:
#define PINMUX_USART1_RXD PINMUX_USART1_RXD_1
#define PINMUX_USART1_TXD PINMUX_USART1_TXD_1
In arch/avr/src/at91uc3/at91uc3b_pinmux.h:
#define PINMUX_USART1_RXD_1 (GPIO_PERIPH | GPIO_FUNCD | GPIO_PORTA | 17)
#define PINMUX_USART1_TXD_1 (GPIO_PERIPH | GPIO_FUNCA | GPIO_PORTA | 23)
PA17 and PA23 are avaiable from the AVR32DEV1:
GPIO PIN Header 16X2 (J2)
----- ----- ----------------
PA17 PIN37 Pin 5
PA23 PIN47 Pin 15
and, of course, +5V and ground.
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 Toolchains
^^^^^^^^^^^^^^
The build logic in these directories assume that you are using the GNU
toolchain with the Atmel patches. The patch file, pre-patched tool sources,
and pre-built binaries are available from the Atmel website.
CONFIG_AVR32_AVRTOOLSW=y # Use the windows version
CONFIG_AVR32_AVRTOOLSL=y # Ue the Linux version
NOTE: The NuttX builtroot cannot be used to build the AVR32 toolchain.
This is because the Atmel patches that add support for the AVR32 are not
included in the NuttX buildroot.
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.
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/avr/src/at91uc3,
arch/avr/src/common, arch/arm/src/avr, 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/avr/src/avr3/up_nommuhead.S.
AVR32 Bootloader
^^^^^^^^^^^^^^^^
Boot Sequence
-------------
"An AVR UC3 part having the bootloader programmed resets as any other
part at 80000000h. Bootloader execution begins here. The bootloader
first performs the boot process to know whether it should start the
USB DFU ISP or the application. If the tested conditions indicate
that the USB DFU ISP should be started, then execution continues in
the bootloader area, i.e. between 80000000h and 80002000h, else
the bootloader launches the application at 80002000h."
Link Address
------------
The linker scripts (ld.script) assume that you are using the DFU
bootloader. The bootloader resides at 0x8000:0000 and so the ld.script
files link the application to execute after the bootloader at
0x8000:2000. To link so that NuttX boots directly without using the
bootloader, change the flash definition from:
flash (rxai!w) : ORIGIN = 0x80002000, LENGTH = 256K - 8K
to:
flash (rxai!w) : ORIGIN = 0x80000000, LENGTH = 256K
Or to use the MSC bootloader:
flash (rxai!w) : ORIGIN = 0x80008000, LENGTH = 256K - 32K
Entering the ISP
----------------
In order to use the USB port to download the FLASH(ISP), you need to
use the S3(PA13) to make CPU return to boot status. In this mode, the
on chip bootloader will run, making the ISP possible.
AVR32DEV1 Configuration Options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
CONFIG_ARCH - Identifies the arch/ subdirectory. This should
be set to:
CONFIG_ARCH=avr
CONFIG_ARCH_family - For use in C code:
CONFIG_ARCH_AVR=y
CONFIG_ARCH_architecture - For use in C code:
CONFIG_ARCH_AVR32=y
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP=at91uc3
CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:
CONFIG_ARCH_CHIP_AT91UC3B0256
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=avr32dev1 (for the AV32DEV1 board)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_AVR32DEV1
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 (SRAM in this case):
CONFIG_DRAM_SIZE=0x00010000 (64Kb)
CONFIG_DRAM_START - The start address of installed DRAM
CONFIG_DRAM_START=0x20000000
CONFIG_DRAM_END - Last address+1 of installed RAM
CONFIG_DRAM_END=(CONFIG_DRAM_START+CONFIG_DRAM_SIZE)
CONFIG_ARCH_IRQPRIO - The AT91UC3B0256 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_AVR32_GPIOIRQ - GPIO interrupt support
CONFIG_AVR32_GPIOIRQSETA - Set of GPIOs on PORTA that support interrupts
CONFIG_AVR32_GPIOIRQSETB - Set of GPIOs on PORTB that support interrupts
CONFIG_AVR32_USARTn - Enable support for USARTn
CONFIG_AVR32_USARTn_RS232 - Configure USARTn as an RS232 interface.
CONFIG_AVR32_USARTn_SPI - Configure USARTn as an SPI interface.
CONFIG_AVR32_USARTn_RS485 - Configure USARTn as an RS485 interface.
CONFIG_AVR32_USARTn_MAN - Configure USARTn as an Manchester interface.
CONFIG_AVR32_USARTn_MODEM - Configure USARTn as an Modem interface.
CONFIG_AVR32_USARTn_IRDA - Configure USARTn as an IRDA interface.
CONFIG_AVR32_USARTn_ISO786 - Configure USARTn as an ISO786 interface.
AT91UC3B0256 specific device driver settings
CONFIG_USARTn_SERIAL_CONSOLE - selects the USARTn for the
console and ttys0 (default is the USART0).
CONFIG_USARTn_RXBUFSIZE - Characters are buffered as received.
This specific the size of the receive buffer
CONFIG_USARTn_TXBUFSIZE - Characters are buffered before
being sent. This specific the size of the transmit buffer
CONFIG_USARTn_BAUD - The configure BAUD of the USART. Must be
CONFIG_USARTn_BITS - The number of bits. Must be either 7 or 8.
CONFIG_USARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
CONFIG_USARTn_2STOP - Two stop bits
Configurations
^^^^^^^^^^^^^^
Each Stellaris LM3S6965 Evaluation Kit configuration is maintained in a
sudirectory and can be selected as follow:
cd tools
./configure.sh avr32dev1/<subdir>
cd -
. ./setenv.sh
Where <subdir> is one of the following:
ostest:
This configuration directory, performs a simple OS test using
examples/ostest.
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