README
^^^^^^
This README discusses issues unique to NuttX configurations for the
Atmel SAM3U-EK development board.
Contents
^^^^^^^^
- Development Environment
- GNU Toolchain Options
- IDEs
- NuttX EABI "buildroot" Toolchain
- NuttX OABI "buildroot" Toolchain
- NXFLAT Toolchain
- LEDs
- SAM3U-EK-specific Configuration Options
- 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. Testing was performed using the Cygwin
environment.
GNU Toolchain Options
^^^^^^^^^^^^^^^^^^^^^
The NuttX make system has been modified to support the following different
toolchain options.
1. The CodeSourcery GNU toolchain,
2. The devkitARM GNU toolchain, ok
4. The NuttX buildroot Toolchain (see below).
All testing has been conducted using the NuttX buildroot toolchain. However,
the make system is setup to default to use the devkitARM toolchain. To use
the CodeSourcery, devkitARM or Raisonance GNU toolchain, you simply need to
add one of the following configuration options to your .config (or defconfig)
file:
CONFIG_SAM34_CODESOURCERYW=y : CodeSourcery under Windows
CONFIG_SAM34_CODESOURCERYL=y : CodeSourcery under Linux
CONFIG_SAM34_DEVKITARM=y : devkitARM under Windows
CONFIG_SAM34_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default)
If you are not using CONFIG_SAM34_BUILDROOT, then you may also have to modify
the PATH in the setenv.h file if your make cannot find the tools.
NOTE: the CodeSourcery (for Windows), devkitARM, and Raisonance toolchains are
Windows native toolchains. The CodeSourcey (for Linux) and NuttX buildroot
toolchains are Cygwin and/or Linux native toolchains. There are several limitations
to using a Windows based toolchain in a Cygwin environment. The three biggest are:
1. The Windows toolchain cannot follow Cygwin paths. Path conversions are
performed automatically in the Cygwin makefiles using the 'cygpath' utility
but you might easily find some new path problems. If so, check out 'cygpath -w'
2. Windows toolchains cannot follow Cygwin symbolic links. Many symbolic links
are used in Nuttx (e.g., include/arch). The make system works around these
problems for the Windows tools by copying directories instead of linking them.
But this can also cause some confusion for you: For example, you may edit
a file in a "linked" directory and find that your changes had no effect.
That is because you are building the copy of the file in the "fake" symbolic
directory. If you use a Windows toolchain, you should get in the habit of
making like this:
make clean_context all
An alias in your .bashrc file might make that less painful.
3. Dependencies are not made when using Windows versions of the GCC. This is
because the dependencies are generated using Windows pathes which do not
work with the Cygwin make.
MKDEP = $(TOPDIR)/tools/mknulldeps.sh
NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
level of -Os (See Make.defs). It will work with -O0, -O1, or -O2, but not with
-Os.
NOTE 2: The devkitARM toolchain includes a version of MSYS make. Make sure that
the paths to Cygwin's /bin and /usr/bin directories appear BEFORE the devkitARM
path or will get the wrong version of make.
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 (There is a simple RIDE project
in the RIDE subdirectory).
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/arm/src/sam34,
arch/arm/src/common, arch/arm/src/armv7-m, 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/arm/src/sam34/sam_vectors.S. You may need to build NuttX
one time from the Cygwin command line in order to obtain the pre-built
startup object needed by RIDE.
NuttX EABI "buildroot" Toolchain
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
A GNU GCC-based toolchain is assumed. The files */setenv.sh 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
SourceForge download site (https://sourceforge.net/projects/nuttx/files/buildroot/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh sam3u-ek/<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 configs/cortexm3-eabi-defconfig-4.6.3 .config
6. make oldconfig
7. make
8. Edit setenv.h, if necessary, so that the PATH variable includes
the path to the newly built binaries.
See the file configs/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-M3 toolchain for Cygwin under Windows.
NOTE: Unfortunately, the 4.6.3 EABI toolchain is not compatible with the
the NXFLAT tools. See the top-level TODO file (under "Binary loaders") for
more information about this problem. If you plan to use NXFLAT, please do not
use the GCC 4.6.3 EABI toochain; instead use the GCC 4.3.3 OABI toolchain.
See instructions below.
NuttX OABI "buildroot" Toolchain
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The older, OABI buildroot toolchain is also available. To use the OABI
toolchain:
1. When building the buildroot toolchain, either (1) modify the cortexm3-eabi-defconfig-4.6.3
configuration to use EABI (using 'make menuconfig'), or (2) use an exising OABI
configuration such as cortexm3-defconfig-4.3.3
2. Modify the Make.defs file to use the OABI conventions:
+CROSSDEV = arm-nuttx-elf-
+ARCHCPUFLAGS = -mtune=cortex-m3 -march=armv7-m -mfloat-abi=soft
+NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-gotoff.ld -no-check-sections
-CROSSDEV = arm-nuttx-eabi-
-ARCHCPUFLAGS = -mcpu=cortex-m3 -mthumb -mfloat-abi=soft
-NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-pcrel.ld -no-check-sections
NXFLAT Toolchain
^^^^^^^^^^^^^^^^
If you are *not* using the NuttX buildroot toolchain and you want to use
the NXFLAT tools, then you will still have to build a portion of the buildroot
tools -- just the NXFLAT tools. The buildroot with the NXFLAT tools can
be downloaded from the NuttX SourceForge download site
(https://sourceforge.net/projects/nuttx/files/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh lpcxpresso-lpc1768/<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 configs/cortexm3-defconfig-nxflat .config
6. make oldconfig
7. make
8. Edit setenv.h, if necessary, so that the PATH variable includes
the path to the newly builtNXFLAT binaries.
LEDs
^^^^
The SAM3U-EK board has four LEDs labeled LD1, LD2, LD3 and LD4 on the
the board. Usage of these LEDs is defined in include/board.h and src/up_leds.c.
They are encoded as follows:
SYMBOL Meaning LED0* LED1 LED2
------------------- ----------------------- ------- ------- -------
LED_STARTED NuttX has been started OFF OFF OFF
LED_HEAPALLOCATE Heap has been allocated OFF OFF ON
LED_IRQSENABLED Interrupts enabled OFF ON OFF
LED_STACKCREATED Idle stack created OFF ON ON
LED_INIRQ In an interrupt** N/C FLASH N/C
LED_SIGNAL In a signal handler*** N/C N/C FLASH
LED_ASSERTION An assertion failed FLASH N/C N/C
LED_PANIC The system has crashed FLASH N/C N/C
* If LED1 and LED2 are statically on, then NuttX probably failed to boot
and these LEDs will give you some indication of where the failure was
** The normal state is LED0=OFF, LED2=ON and LED1 faintly glowing. This faint
glow is because of timer interupts that result in the LED being illuminated
on a small proportion of the time.
*** LED2 may also flicker normally if signals are processed.
SAM3U-EK-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_CORTEXM3=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_SAM3U
CONFIG_ARCH_CHIP_AT91SAM3U4
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=sam3u-ek (for the SAM3U-EK development board)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_SAM3UEK=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_DRAM_SIZE - Describes the installed DRAM (SRAM in this case):
CONFIG_DRAM_SIZE=0x0000c000 (48Kb)
CONFIG_DRAM_START - The start address of installed DRAM
CONFIG_DRAM_START=0x20000000
CONFIG_ARCH_IRQPRIO - The SAM3UF103Z 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_SAM34_RTC - Real Time Clock
CONFIG_SAM34_RTT - Real Time Timer
CONFIG_SAM34_WDT - Watchdog Timer
CONFIG_SAM34_UART0 - UART 0
CONFIG_SAM34_SMC - Static Memory Controller
CONFIG_SAM34_USART0 - USART 0
CONFIG_SAM34_USART1 - USART 1
CONFIG_SAM34_USART2 - USART 2
CONFIG_SAM34_USART3 - USART 3
CONFIG_SAM34_HSMCI - High Speed Multimedia Card Interface
CONFIG_SAM34_TWI0 - Two-Wire Interface 0
CONFIG_SAM34_TWI1 - Two-Wire Interface 1
CONFIG_SAM34_SPI - Serial Peripheral Interface
CONFIG_SAM34_SSC - Synchronous Serial Controller
CONFIG_SAM34_TC0 - Timer Counter 0
CONFIG_SAM34_TC1 - Timer Counter 1
CONFIG_SAM34_TC2 - Timer Counter 2
CONFIG_SAM34_PWM - Pulse Width Modulation Controller
CONFIG_SAM34_ADC12B - 12-bit ADC Controller
CONFIG_SAM34_ADC - 10-bit ADC Controller
CONFIG_SAM34_DMA - DMA Controller
CONFIG_SAM34_UDPHS - USB Device High Speed
Some subsystems can be configured to operate in different ways. The drivers
need to know how to configure the subsystem.
CONFIG_GPIOA_IRQ
CONFIG_GPIOB_IRQ
CONFIG_GPIOC_IRQ
CONFIG_USART0_ISUART
CONFIG_USART1_ISUART
CONFIG_USART2_ISUART
CONFIG_USART3_ISUART
CONFIG_SAM34_NAND - NAND memory
AT91SAM3U 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
LCD Options. Other than the standard LCD configuration options
(see configs/README.txt), the SAM3U-EK driver also supports:
CONFIG_LCD_PORTRAIT - Present the display in the standard 240x320
"Portrait" orientation. Default: The display is rotated to
support a 320x240 "Landscape" orientation.
Configurations
^^^^^^^^^^^^^^
Each SAM3U-EK configuration is maintained in a sub-directory and
can be selected as follow:
cd tools
./configure.sh sam3u-ek/<subdir>
cd -
. ./setenv.sh
Before sourcing the setenv.sh file above, you should examine it and perform
edits as necessary so that BUILDROOT_BIN is 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:
knsh:
This is identical to the nsh configuration below except that NuttX
is built as a kernel-mode, monolithic module and the user applications
are built separately. It is recommends to use a special make command;
not just 'make' but make with the following two arguments:
make pass1 pass2
In the normal case (just 'make'), make will attempt to build both user-
and kernel-mode blobs more or less interleaved. This actual works!
However, for me it is very confusing so I prefer the above make command:
Make the user-space binaries first (pass1), then make the the kernel-space
binaries (pass2)
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
and misc/tools/README.txt.
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. Uses the older, OABI, buildroot toolchain. But that is easily
reconfigured:
CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : Buildroot toolchain
CONFIG_ARMV7M_OABI_TOOLCHAIN=y : Older, OABI toolchain
3. At the end of the build, there will be several files in the top-level
NuttX build directory:
PASS1:
nuttx_user.elf - The pass1 user-space ELF file
nuttx_user.hex - The pass1 Intel HEX format file (selected in defconfig)
User.map - Symbols in the user-space ELF file
PASS2:
nuttx - The pass2 kernel-space ELF file
nuttx.hex - The pass2 Intel HEX file (selected in defconfig)
System.map - Symbols in the kernel-space ELF file
The J-Link programmer will except files in .hex, .mot, .srec, and .bin
formats.
4. Combining .hex files. If you plan to use the .hex files with your
debugger or FLASH utility, then you may need to combine the two hex
files into a single .hex file. Here is how you can do that.
a. The 'tail' of the nuttx.hex file should look something like this
(with my comments added):
$ tail nuttx.hex
# 00, data records
...
:10 9DC0 00 01000000000800006400020100001F0004
:10 9DD0 00 3B005A0078009700B500D400F300110151
:08 9DE0 00 30014E016D0100008D
# 05, Start Linear Address Record
:04 0000 05 0800 0419 D2
# 01, End Of File record
:00 0000 01 FF
Use an editor such as vi to remove the 05 and 01 records.
b. The 'head' of the nuttx_user.hex file should look something like
this (again with my comments added):
$ head nuttx_user.hex
# 04, Extended Linear Address Record
:02 0000 04 0801 F1
# 00, data records
:10 8000 00 BD89 01084C800108C8110208D01102087E
:10 8010 00 0010 00201C1000201C1000203C16002026
:10 8020 00 4D80 01085D80010869800108ED83010829
...
Nothing needs to be done here. The nuttx_user.hex file should
be fine.
c. Combine the edited nuttx.hex and un-edited nuttx_user.hex
file to produce a single combined hex file:
$ cat nuttx.hex nuttx_user.hex >combined.hex
Then use the combined.hex file with the to write the FLASH image.
If you do this a lot, you will probably want to invest a little time
to develop a tool to automate these steps.
nsh:
Configures the NuttShell (nsh) located at examples/nsh. The
Configuration enables both the serial and telnetd NSH interfaces.
nx:
Configures to use examples/nx using the HX834x LCD hardwar on
the SAM3U-EK development board.
ostest:
This configuration directory, performs a simple OS test using
examples/ostest. By default, this project assumes that you are
using the DFU bootloader.
touchscreen:
This configuration implements an NSH configuratin with several
built-in applications. The configuration is called touchscreen
because we intend to use this configuration to develop the
SAM3U-EK touchscreen. However, there is no touchscreen driver
in place as of this writing.
