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README
^^^^^^
README for NuttX port to the Stellaris RDK-S2E Reference Design Kit and
the MDL-S2E Ethernet to Serial module.
Contents
^^^^^^^^
Stellaris RDK-S2E Reference Design Kit
Development Environment
GNU Toolchain Options
IDEs
NuttX EABI "buildroot" Toolchain
NuttX OABI "buildroot" Toolchain
NXFLFAT Toolchain
Stellaris MDL-S2E Reference Design Configuration Options
Configurations
Stellaris RDK-S2E Reference Design Kit
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The Stellaris RDK-S2E Reference Design Kit includes the following features:
o MDL-S2E Ethernet to serial module
o LM3S6432 in a 10 x 10 mm BGA package for reduced board size
o 10/100 Mbit Ethernet port
o Auto MDI/MDIX cross-over correction
o Traffic and link indicators Serial ports
o UART ports include RTS/CTS for flow control
o UART0 has RS232 levels, transceiver runs at up to 230.4 Kbaud
o UART1 has CMOS/TTL levels, can run at 1.0 Mbaud
Features of the LM3S6432 Microcontroller
o 32-bit RISC performance using ARM® Cortex™-M3 v7M architecture
- 50-MHz operation
- Hardware-division and single-cycle-multiplication
- Integrated Nested Vectored Interrupt Controller (NVIC)
- 42 interrupt channels with eight priority levels
o 96 KB single-cycle flash
o 32 KB single-cycle SRAM
o Three general-purpose 32-bit timers
o Integrated Ethernet MAC and PHY
o Two fully programmable 16C550-type UARTs
o Three 10-bit channels (inputs) when used as single-ended inputs
o Two independent integrated analog comparators
o One I2C module
o One PWM generator block
– One 16-bit counter
– Two comparators
– Produces two independent PWM signals
– One dead-band generator
o 0 to 43 GPIOs, depending on user configuration
o On-chip low drop-out (LDO) voltage regulator
GPIO Usage
PIN SIGNAL Function
--- ----------------- ---------------------------------------
L3 PA0/U0RX UART0 receive
M3 PA1/U0TX UART0 transmit
E12 PB0/U0CTS UART0 CTS
D12 PB1/U0RTS UART0 RTS
L5 PA4/SPIRX SPI receive (pin hardwired to U1RX)
M5 PA5/SPITX SPI transmit (pin hardwired to U1TX)
H2 PD2/U1RX UART1 receive
H1 PD3/U1TX UART1 transmit
L4 PA3/U1CTS/SPICLK UART1 CTS or SPI clock
M4 PA2/U1RTS/SPISEL UART1 RTS or SPI slave select
J11 PF0/LED1 Ethernet LED1 (green)
J12 PF1/LED0 Ethernet LED0 (yellow)
C11 PB2 Transciever #INVALID
C12 PB3 Transciever #ENABLE
A6 PB4 Transciever ON
B7 PB5 Transciever #OFF
Development Environment
^^^^^^^^^^^^^^^^^^^^^^^
Either Linux, Mac OS X 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 GCC on
Mac OS X.
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,
3. The NuttX buildroot Toolchain (see below).
To use a specific toolchain, you simply need to add one of the following
configuration options to your .config (or defconfig) file:
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery under Windows
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYL=y : CodeSourcery under Linux or on Mac OS X.
CONFIG_ARMV7M_TOOLCHAIN_DEVKITARM=y : devkitARM under Windows
CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default)
You may also have to modify the PATH environment variable if your make cannot
find the tools.
NOTE: the CodeSourcery (for Windows) and devkitARM 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.
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.
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/lm,
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/tiva/tiva_vectors.S.
NuttX EABI "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-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
Bitbucket download site (https://bitbucket.org/nuttx/buildroot/downloads/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
This port was tested with tools built using summon-arm-toolchain; available
from https://github.com/esden/summon-arm-toolchain, however the buildroot
instructions should apply for other platforms.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh lm3s6432-s2e/<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. Make sure 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 Bitbucket download site
(https://bitbucket.org/nuttx/nuttx/downloads/).
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. Make sure that the PATH variable includes the path to the newly built
NXFLAT binaries.
Stellaris MDL-S2E Reference Design 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=lm
CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:
CONFIG_ARCH_CHIP_LM3S6432
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=lm3s6432-s2e (for the Stellaris MDL-S2E Reference Design)
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_LM3S6432S2E
CONFIG_ARCH_LOOPSPERMSEC - As supplied, calibrated for correct operation
of delay loops assuming 50MHz CPU frequency.
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=0x00010000 (64Kb)
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.
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.
There are configurations for disabling support for interrupts GPIO ports.
GPIOH and GPIOJ must be disabled because they do not exist on the LM3S6432.
Additional interrupt support can be disabled if desired to reduce memory
footprint - GPIOs C-G are not pinned out on the MDL-S2E board.
CONFIG_TIVA_GPIOA_IRQS=y
CONFIG_TIVA_GPIOB_IRQS=y
CONFIG_TIVA_GPIOC_IRQS=n << Always
CONFIG_TIVA_GPIOD_IRQS=n << Always
CONFIG_TIVA_GPIOE_IRQS=n << Always
CONFIG_TIVA_GPIOF_IRQS=n << Always
CONFIG_TIVA_GPIOG_IRQS=n << Always
CONFIG_TIVA_GPIOH_IRQS=n << Always
CONFIG_TIVA_GPIOJ_IRQS=n << Always
LM3S6432 specific device driver settings
CONFIG_UARTn_DISABLE
The TX and RX pins for UART1 share I/O pins with the TX and RX pins
for SSI0. To avoid conflicts, only one of SSI0 and UART1 should
be enabled in a configuration.
CONFIG_UARTn_SERIAL_CONSOLE - selects the UARTn for the
console and ttys0 (default is UART1).
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_TIVA_SSI0 - Select to enable support for SSI0
The TX and RX pins for SSI0 share I/O pins with the TX and RX pins
for UART1. To avoid conflicts, only one of SSI0 and UART1 should
be enabled in a configuration.
CONFIG_TIVA_SSI1 - Select to enable support for SSI1
Note that the LM3S6432 only has one SSI, so SSI1 should always be
disabled.
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_TIVA_ETHERNET - This must be set (along with CONFIG_NET)
to build the Stellaris Ethernet driver
CONFIG_TIVA_ETHLEDS - Enable to use Ethernet LEDs on the board.
CONFIG_TIVA_BOARDMAC - This should be set in order to use the
MAC address configured in the flash USER registers.
CONFIG_TIVA_ETHHDUPLEX - Set to force half duplex operation
CONFIG_TIVA_ETHNOAUTOCRC - Set to suppress auto-CRC generation
CONFIG_TIVA_ETHNOPAD - Set to suppress Tx padding
CONFIG_TIVA_MULTICAST - Set to enable multicast frames
CONFIG_TIVA_PROMISCUOUS - Set to enable promiscuous mode
CONFIG_TIVA_BADCRC - Set to enable bad CRC rejection.
CONFIG_TIVA_DUMPPACKET - Dump each packet received/sent to the console.
Configurations
^^^^^^^^^^^^^^
Each Stellaris MDL-S2E Reference Design configuration is maintained in a
sub-directory and can be selected as follow:
cd tools
./configure.sh lm3s6432-s2e/<subdir>
cd -
Where <subdir> is one of the following:
nsh:
Configures the NuttShell (nsh) located at examples/nsh. The
Configuration enables both the serial and telnetd NSH interfaces.
NOTE: As it is configured now, you MUST have a network connected.
Otherwise, the NSH prompt will not come up because the Ethernet
driver is waiting for the network to come up. That is probably
a bug in the Ethernet driver behavior!
