README.txt
This README file discusses the port of NuttX to the Embedded Artists LPC4088 QuickStart board: See https://www.embeddedartists.com/products/lpc4088-quickstart-board/. This board features the NXP LPC4088FET208 MCU.
CONTENTS
o LEDs o Buttons o Serial Console o Using OpenOCD with the Olimex ARM-USB-OCD o Loading Code with the ISP Board o Configuration
LEDs
The LCP4088 Quickstart board has four user LEDs
LED1 : Connected to P1[18]
LED2 : Connected to P0[13]
LED3 : Connected to P1[13]
LED4 : Connected to P2[19]
If CONFIG_ARCH_LEDS is not defined, then the user can control the LEDs in any way using the definitions provided in the board.h header file.
If CONFIG_ARCH_LEDs is defined, then NuttX will control the 4 LEDs on the LPC4088 QuickStart board. The following definitions describe how NuttX controls the LEDs: LED1 LED2 LED3 LED4 LED_STARTED OFF OFF OFF OFF LED_HEAPALLOCATE ON OFF OFF OFF LED_IRQSENABLED OFF ON OFF OFF LED_STACKCREATED ON ON OFF OFF LED_INIRQ LED3 glows, on while in interrupt LED_SIGNAL LED3 glows, on while in signal handler LED_ASSERTION LED3 glows, on while in assertion LED_PANIC LED3 Flashes at 2Hz LED_IDLE LED glows: ON while active; OFF while sleeping
Buttons
The LPC4088 QuickStart board supports a single button:
USER1 : Connected to P2[10]
This can be accessed using the definitions and interfaces defined in the board.h header file.
Serial Console
By Default, UART0 is used as the serial console in all configurations. This may be connected to your computer via an external RS-232 driver or via the onboard MBED interface.
As an option, UART1 can also be used for the serial console. You might want, to do this, for example, if you use UART0 for the ISP function and you want to use a different UART for console output. UART1 can be configured as the serial console by changing the configuration as follows:
System Type:
CONFIG_LPC17_40_UART0=n : Disable UART0 if it is no longer used
CONFIG_LPC17_40_UART1=y : Enable UART1
Drivers:
CONFIG_UART1_SERIAL_CONSOLE=y : Setup up the UART1 configuration
CONFIG_UART1_RXBUFSIZE=256
CONFIG_UART1_TXBUFSIZE=256
CONFIG_UART1_BAUD=115200
CONFIG_UART1_BITS=8
CONFIG_UART1_PARITY=0
CONFIG_UART1_2STOP=0
Using OpenOCD with the Olimex ARM-USB-OCD
Building OpenOCD under Cygwin:
Refer to boards/olimex-lpc1766stk/README.txt
Installing OpenOCD in Ubuntu Linux:
sudo apt-get install openocd
Helper Scripts.
I have been using the Olimex ARM-USB-OCD debugger. OpenOCD
requires a configuration file. I keep the one I used last here:
boards/arm/lpc17xx_40xx/lpc4088-quickstart/tools/lpc4088-quickstart.cfg
However, the "correct" configuration script to use with OpenOCD may
change as the features of OpenOCD evolve. So you should at least
compare that lpc4088-quickstart.cfg file with configuration files in
/usr/share/openocd/scripts. As of this writing, the configuration
files of interest were:
/usr/local/share/openocd/scripts/interface/openocd-usb.cfg
This is the configuration file for the Olimex ARM-USB-OCD
debugger. Select a different file if you are using some
other debugger supported by OpenOCD.
/usr/local/share/openocd/scripts/board/?
I don't see a board configuration file for the LPC4088 Quickstart.
/usr/local/share/openocd/scripts/target/lpc40xx.cfg
This is the configuration file for the LPC4088 target.
It just sets up a few parameters then sources lpc1xxx.cfg
/usr/local/share/openocd/scripts/target/lpc1xxx.cfg
This is the generic LPC configuration for the LPC1xxx
family. It is included by lpc40xx.cfg.
NOTE: These files could also be located under /usr/share in some
installations. They could be most anywhwere if you are using a
windows version of OpenOCD.
boards/arm/lpc17xx_40xx/lpc4088-quickstart/tools/lpc4088-quickstart.cfg
This is simply openocd-usb.cfg, lpc40xx.cfg, and lpc1xxx.cfg
concatenated into one file for convenience. Don't use it
unless you have to.
There is also a script on the tools/ directory that I use to start
the OpenOCD daemon on my system called oocd.sh. That script will
probably require some modifications to work in another environment:
- Possibly the value of OPENOCD_PATH and TARGET_PATH
- It assumes that the correct script to use is the one at
boards/arm/lpc17xx_40xx/lpc4088-quickstart/tools/lpc4088-quickstart.cfg
Starting OpenOCD
Then you should be able to start the OpenOCD daemon as follows. This
assumes that you have already CD'ed to the NuttX build directory and
that you have set the full path to the
boards/arm/lpc17xx_40xx/lpc4088-quickstart/tools
in your PATH environment variable:
oocd.sh $PWD
or, if the PATH variable is not so configured:
boards/arm/lpc17xx_40xx/lpc4088-quickstart/tools/oocd.sh $PWD
Connecting GDB
Once the OpenOCD daemon has been started, you can connect to it via
GDB using the following GDB command:
arm-nuttx-elf-gdb
(gdb) target remote localhost:3333
NOTE: The name of your GDB program may differ. For example, with the
CodeSourcery toolchain, the ARM GDB would be called arm-none-eabi-gdb.
OpenOCD will support several special 'monitor' sub-commands. You can
use the 'monitor' (or simply 'mon') command to invoke these sub-
commands. These GDB commands will send comments to the OpenOCD monitor.
Here are a couple that you will need to use:
(gdb) monitor reset
(gdb) monitor halt
NOTES:
1. The MCU must be halted using 'monitor halt' prior to loading code.
2. 'monitor reset' will restart the processor after loading code.
3. The 'monitor' command can be abbreviated as just 'mon'.
After starting GDB, you can load the NuttX ELF file like this:
(gdb) mon halt
(gdb) load nuttx
NOTES:
1. NuttX should have been built so that it has debugging symbols
(by setting CONFIG_DEBUG_SYMBOLS=y in the .config file).
2. The MCU must be halted prior to loading code.
3. I find that there are often undetected write failures when using
the Olimex ARM-USB-OCD debugber and that if you start the program
with a bad FLASH failure, it will lock up OpenOCD. I usually
oad nuttx twice, restarting OpenOCD in between in order to assure
good FLASH contents:
(gdb) mon halt
(gdb) load nuttx
(gdb) mon reset
Exit GDB, kill the OpenOCD server, recycle power on the board,
restart the OpenOCD server and GDB, then:
(gdb) mon halt
(gdb) load nuttx
(gdb) mon reset
Other debuggers may not have these issues and such drastic steps may
not be necessary.
Loading Code with the ISP Board
Users can also load code onto the board using a built-in or external UART to USB adapter on UART0. I use the FlashMagic program for Windows available here: http://www.flashmagictool.com/ . It is so easy to use that no further explanation should be necessary: Just select the LPC4088, the ISP COM port, and the NuttX .hex file and program it.
CONFIGURATION
Information Common to All Configurations
These configurations use 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 README.txt.
b. Execute 'make menuconfig' in nuttx/ in order to start the reconfiguration process.
Most (but not all) configurations use the "GNU Tools for ARM Embedded Processors" that is maintained by ARM:
https://developer.arm.com/open-source/gnu-toolchain/gnu-rm
unless otherwise stated.
That toolchain selection can easily be reconfigured using 'make menuconfig'. Here are the relevant current settings:
Build Setup: CONFIG_HOST_WINDOWS=y : Window environment CONFIG_WINDOWS_CYGWIN=y : Cywin under Windows
System Type -> Toolchain: CONFIG_ARM_TOOLCHAIN_GNU_EABI=y : GNU ARM EABI toolchain
By Default, UART0 is used as the serial console in all configurations. This may be connected to your computer via an external RS-232 driver or via the onboard MBED interface. See the section above entitled "Serial Console" for other options.
An LCD is available for this board, but I don't have one to test with. If you wish to use any of the configurations below which utilize the LCD, you will need to tweak the LCD pin definitions in board.h.
Configuration Directories
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. Is is recommended 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 kernel-space
binaries (pass2)
1. Uses the older, OABI, buildroot toolchain. But that is easily
reconfigured:
CONFIG_ARM_TOOLCHAIN_BUILDROOT=y : Buildroot toolchain
CONFIG_ARM_TOOLCHAIN_BUILDROOT_OABI=y : Older, OABI toolchain
2. 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
Loading these .elf files with OpenOCD is tricky. It appears to me
that when nuttx_user.elf is loaded, it destroys the nuttx image
in FLASH. But loading the nuttx ELF does not harm the nuttx_user.elf
in FLASH. Conclusion: Always load nuttx_user.elf before nuttx.
Just to complicate matters, it is sometimes the case that you need
load objects twice to account for write failures. I have not yet
found a simple foolproof way to reliably get the code into FLASH.
3. 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.
STATUS:
2019-04-23: Untested with LPC4088.
nsh
Configures the NuttShell (nsh) located at examples/nsh. The Configuration enables only the serial NSH interface.
NOTES:
1. Uses the older, OABI, buildroot toolchain. But that is easily
reconfigured:
CONFIG_ARM_TOOLCHAIN_BUILDROOT=y : Buildroot toolchain
CONFIG_ARM_TOOLCHAIN_BUILDROOT_OABI=y : Older, OABI toolchain
2. This NSH has support for built-in applications enabled, however,
no built-in configurations are built in the defulat configuration.
3. This configuration has DMA-based SD card support enabled by
default. That support can be disabled as follow:
CONFIG_LPC17_40_GPDMA=n : No DMA
CONFIG_ARCH_DMA=n
CONFIG_LPC17_40_SDCARD=n : No SD card driver
CONFIG_SDIO_DMA=n : No SD card DMA
CONFIG_MMCSD=n : No MMC/SD driver support
CONFIG_FS_FAT=n : No FAT file system support
4. This configuration has been used for verifying SDRAM by modifying
the configuration in the following ways:
CONFIG_LPC17_40_EMC=y : Enable the EMC
CONFIG_LPC17_40_EXTDRAM=y : Configure external DRAM
CONFIG_LPC17_40_EXTDRAMSIZE=67108864 : DRAM size 2x256/8 = 64MB
CONFIG_TESTING_RAMTEST=y : Enable the RAM test built-in
In this configuration, the SDRAM is not added to heap and so is
not excessible to the applications. So the RAM test can be
freely executed against the SRAM memory beginning at address
0xa000:0000 (CS0).
6. This configuration has been used for verifying the touchscreen on
on the 4.3" LCD module.
a) As of this writing, this touchscreen is still not functional.
Rommel Marcelo has tracked this problem down to noise on the
PENIRQ interrupt. There are so many false interrupts that
the NuttX interrupt-driven touchscreen driver cannot be used.
Other compatible LCDs, however, may not have this issue.
b) You can enable the touchscreen by modifying the configuration
in the following ways:
Drivers:
CONFIG_INPUT=y : Enable support for input devices
CONFIG_INPUT_ADS7843E=y : Enable support for the XPT2048
CONFIG_ADS7843E_SPIDEV=1 : Use SSP1 for communication
CONFIG_SPI=y : Enable SPI support
CONFIG_SPI_EXCHANGE=n : exchange() method is not supported
System Type:
CONFIG_LPC17_40_GPIOIRQ=y : GPIO interrupt support
CONFIG_LPC17_40_SSP1=y : Enable support for SSP1
Library Support:
CONFIG_SCHED_WORKQUEUE=y : Work queue support required
Application Configuration:
CONFIG_EXAMPLES_TOUCHSCREEN=y : Enable the touchscreen built-int test
Defaults should be okay for related touchscreen settings. Touchscreen
debug output can be enabled with:
Build Setup:
CONFIG_DEBUG_FEATURES=y : Enable debug features
CONFIG_DEBUG_INFO=y : Enable verbose debug output
CONFIG_DEBUG_INPUT=y : Enable debug output from input devices
c) You will also have to disable SD card support to use this test. The
SD card detect (CD) signal is on P0[13]. This signal is shared. It
is also used for MOSI1 and USB_UP_LED. The CD pin may be disconnected.
There is a jumper on board that enables the CD pin. OR, you can simply
remove the SD module so that it does not drive the CD pin.
Drivers:
CONFIG_MMCSD=n : No MMC/SD driver support
System Type:
CONFIG_LPC17_40_GPDMA=n : No DMA
CONFIG_LPC17_40_SDCARD=n : No SD card driver
CONFIG_SDIO_DMA=n : No SD card DMA
CONFIG_ARCH_DMA=n
File Systems:
CONFIG_FS_FAT=n : No FAT file system support
For touchscreen debug output:
Build Setup:
CONFIG_DEBUG_FEATURES=y
CONFIG_DEBUG_INFO=y
CONFIG_DEBUG_INPUT=y