README
^^^^^^
References:
^^^^^^^^^^
Micromint: http://www.micromint.com/
Luminary: http://www.luminarymicro.com/
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 because the Luminary FLASH programming application was used for
writing to FLASH and this application works only under Windows.
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, or
3. 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 or devkitARM GNU toolchain, you simply need to build the
system as follows:
make # Will build for the devkitARM toolchain
make CROSSDEV=arm-eabi- # Will build for the devkitARM toolchain
make CROSSDEV=arm-none-eabi- # Will build for the CodeSourcery toolchain
make CROSSDEV=arm-elf- # Will build for the NuttX buildroot toolchain
Of course, hard coding this CROSS_COMPILE value in Make.defs file will save
some repetitive typing.
NOTE: the CodeSourcery and devkitARM toolchains are Windows native toolchains.
The NuttX buildroot toolchain is a Cygwin toolchain. 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 not 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; make CROSSDEV=arm-none-eabi-
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.
Support has been added for making dependencies with the CodeSourcery toolchain.
That support can be enabled by modifying your Make.defs file as follows:
- MKDEP = $(TOPDIR)/tools/mknulldeps.sh
+ MKDEP = $(TOPDIR)/tools/mkdeps.sh --winpaths "$(TOPDIR)"
If you have problems with the dependency build (for example, if you are not
building on C:), then you may need to modify tools/mkdeps.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.
NuttX 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/project/showfiles.php?group_id=189573).
This GNU toolchain builds and executes in the Cygwin environment.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh eagle100/<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-4.3.3 .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
detailed PLUS some special instructions that you will need to follow if you are
building a Cortex-M3 toolchain for Cygwin under Windows.
Ethernet-Bootloader
^^^^^^^^^^^^^^^^^^^
Here are some notes about using the Luminary Ethernet boot-loader built
into the Eagle-100 board.
Built-In Application:
- The board has no fixed IP address but uses DHCP to get an address.
I used a D-link router; I can use a web browser to surf to the D-link
web page to get the address assigned by
- Then you can use this IP address in your browser to surf to the Eagle-100
board. It presents several interesting pages -- the most important is
the page called "Firmware Update". That page includes instructions on
how to download code to the Eagle-100.
- After you burn the first program, you lose this application. Then you
will probably be better off connected directly to the Eagle-100 board
or through a switch (The router caused problems for me during downloads).
Using the Ethernet Bootloader:
- You will need the "LM Flash Programmer application". You can get that
program from the Luminary web site. There is a link on the LM3S6918 page.
- Is there any documentation for using the bootloader? Yes and No: There
is an application note covering the bootloader on the Luminary site, but
it is not very informative. The Eagle100 User's Manual has the best
information.
- Are there any special things I have to do in my code, other than setting
the origin to 0x0000:2000 (APP_START_ADDRESS)? No. The bootloader assumes
that you have a vector table at that address . The bootloader does the
following each time it boots (after you have downloaded the first valid
application):
o The bootloader sets the vector table register to the APP_START_ADDRESS,
o It sets the stack pointer to the address at APP_START_ADDRESS, and then
o Jumps to the address at APP_START_ADDRESS+4.
- You can force the bootloader to skip starting the application and stay
in the update mode. You will need to do this in order to download a new
application. You force the update mode by holding the user button on the
Eagle-100 board while resetting the board. The user button is GPIOA, pin 6
(call FORCED_UPDATE_PIN in the bootloader code).
- Note 1: I had to remove my D-Link router from the configuration in order
to use the LM Flash Programmer (the Bootloader issues BOOTP requests to
communicate with the LM Flash Programmer, my router was responding to
these BOOTP requests and hosing the download). It is safer to connect
via a switch or via an Ethernet switch.
- Note 2: You don't need the router's DHCPD server in the download
configuration; the Luminary Flash Programmer has the capability of
temporarily assigning the IP address to the Eagle-100 via BOOTP.
Eagle100-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=lm3s
CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:
CONFIG_ARCH_CHIP_LM3S6918
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=eagle100 (for the MicroMint Eagle-100 development board)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_EAGLE100
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 LM3S6918 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_BOOTLOADER - Configure to use the MicroMint Eagle-100
Ethernet bootloader.
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.
LM3S6818 specific device driver settings
CONFIG_UARTn_SERIAL_CONSOLE - selects the UARTn for the
console and ttys0 (default is the UART0).
CONFIG_UARTn_RXBUFSIZE - Characters are buffered as received.
This specific the size of the receive buffer
CONFIG_UARTn_TXBUFSIZE - Characters are buffered before
being sent. This specific the size of the transmit buffer
CONFIG_UARTn_BAUD - The configure BAUD of the UART. Must be
CONFIG_UARTn_BITS - The number of bits. Must be either 7 or 8.
CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
CONFIG_UARTn_2STOP - Two stop bits
CONFIG_SSI0_DISABLE - Select to disable support for SSI0
CONFIG_SSI1_DISABLE - Select to disable support for SSI1
CONFIG_SSI_POLLWAIT - Select to disable interrupt driven SSI support.
Poll-waiting is recommended if the interrupt rate would be to
high in the interrupt driven case.
CONFIG_SSI_TXLIMIT - Write this many words to the Tx FIFO before
emptying the Rx FIFO. If the SPI frequency is high and this
value is large, then larger values of this setting may cause
Rx FIFO overrun errors. Default: half of the Tx FIFO size (4).
CONFIG_LM3S_ETHERNET - This must be set (along with CONFIG_NET)
to build the LM3S Ethernet driver
CONFIG_LM3S_ETHLEDS - Enable to use Ethernet LEDs on the board.
CONFIG_LM3S_BOARDMAC - If the board-specific logic can provide
a MAC address (via lm3s_ethernetmac()), then this should be selected.
CONFIG_LM3S_ETHHDUPLEX - Set to force half duplex operation
CONFIG_LM3S_ETHNOAUTOCRC - Set to suppress auto-CRC generation
CONFIG_LM3S_ETHNOPAD - Set to suppress Tx padding
CONFIG_LM3S_MULTICAST - Set to enable multicast frames
CONFIG_LM3S_PROMISCUOUS - Set to enable promiscuous mode
CONFIG_LM3S_BADCRC - Set to enable bad CRC rejection.
Configurations
^^^^^^^^^^^^^^
Each Eagle-100 configuration is maintained in a sudirectory and
can be selected as follow:
cd tools
./configure.sh eagle100/<subdir>
cd -
. ./setenv.sh
Where <subdir> is one of the following:
nettest:
This configuration directory may be used to enable networking using the
LM3S6918's Ethernet controller. It uses examples/nettest to excercise the
TCP/IP network.
httpd:
This builds the uIP web server example using the examples/uip application
(for execution from FLASH). See examples/README.txt for information
about ostest.
nsh:
Configures the NuttShell (nsh) located at examples/nsh. The
Configuration enables both the serial and telnetd NSH interfaces.
ostest:
This configuration directory, performs a simple OS test using
examples/ostest.
By default, all of these examples are built to be used with the Luminary
Ethernet Bootloader (you can change the ld.script file in any of these
sub-directories to change that configuration).
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