Olimex LPC-H3131

This documentation discusses the port of NuttX to the Olimex LPC-H3131 board.

Note

This is a minimal port to the Olimex LPC-H3131. According to Olimex documentation, the LPC-H3131 is similar in design to the Embedded Artists EA3131. As a consequence, it should be possible to leverage additional functionality from boards/arm/lpc31xx/ea3131 without too much difficulty.

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.

GNU Toolchain Options

The NuttX make system has been modified to support the following different toolchain options.

1. The NuttX buildroot Toolchain (see below), or

2. Any generic arm-none-eabi GNU toolchain.

All testing has been conducted using the NuttX buildroot toolchain. To use a different toolchain, you simply need to modify the configuration. As an example:

CONFIG_ARM_TOOLCHAIN_GNU_EABI: Generic arm-none-eabi toolchain

Generic arm-none-eabi GNU Toolchain

There are a number of toolchain projects providing support for ARMv4/v5 class processors, including: GCC ARM Embedded

Others exist for various Linux distributions, MacPorts, etc. Any version based on GCC 4.6.3 or later should work.

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 paths: You will need include/, arch/arm/src/lpc31xx, arch/arm/src/common, arch/arm/src/arm, 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/lpc31xx/lpc31_vectors.S. You may have to build NuttX one time from the Cygwin command line in order to obtain the pre-built startup object needed by an IDE.

NuttX 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.

1. You must have already configured NuttX in <some-dir>/nuttx.

$ tools/configure.sh olimex-lpc-h3131:<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.

$ cd <some-dir>/buildroot
$ cp boards/arm926t-defconfig-4.2.4 .config
$ make oldconfig
$ make

5. Make sure that the PATH variable includes the path to the newly built binaries.

See the file boards/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.

Boot Sequence

LPC313x has on chip bootrom which loads properly formatted images from multiple sources into SRAM. These sources include including SPI Flash, NOR Flash, UART, USB, SD Card, and NAND Flash.

In all configurations, NuttX is loaded directly into ISRAM. NuttX is linked to execute from ISRAM, regardless of the boot source.

Buttons and LEDs

Buttons

There are no user buttons on the H3131.

LEDs

There are two LEDs on the LPC-H3131 that can be controlled by software:

LED	Colour	GPIO	Note
LED1	Yellow	GPIO17	High output illuminates
LED2	Green	GPIO18	High output illuminates

Both can be illuminated by driving the GPIO output to high.

These LEDs are not used by the board port unless CONFIG_ARCH_LEDS is defined. In that case, the usage by the board port is defined in include/board.h and src/lpc31_leds.c. The LEDs are used to encode OS-related events as follows:

SYMBOL	Meaning	LED2	LED1
LED_STARTED	NuttX has been started	OFF	OFF
LED_HEAPALLOCATE	Heap has been allocated	OFF	OFF
LED_IRQSENABLED	Interrupts enabled	OFF	OFF
LED_STACKCREATED	Idle stack created	ON	OFF
LED_INIRQ	In an interrupt	N/C	N/C
LED_SIGNAL	In a signal handler	N/C	N/C
LED_ASSERTION	An assertion failed	N/C	N/C
LED_PANIC	The system has crashed	N/C	Blinking
LED_IDLE	MCU is is sleep mode	Not used	Not used

Thus if LED2 is statically on, NuttX has successfully booted and is, apparently, running normmally. If LED1 is flashing at approximately 2Hz, then a fatal error has been detected and the system has halted.

Note

That LED2 is not used after completion of booting and may be used by other board-specific logic.

Image Format

In order to use the bootrom bootloader, a special header must be added to the beginning of the binary image that includes information about the binary (things like the entry point, the size, and CRC’s to verify the image.

NXP provides a Windows program to append such a header to the binary image. However, (1) that program won’t run under Linux, and (2) when I try it under WinXP, Symantec immediately claims that the program is misbehaving and deletes it!

To work around both of these issues, I have created a small program under boards/olimex-lpc-h3131/tools to add the header. This program can be built under either Linux or Cygwin (and probably other tool environments as well). That tool can be built as follows:

$ cd boards/olimex-lpc-h3131/tools
$ make

Then, to build the NuttX binary ready to load with the bootloader, just following these steps:

$ tools/configure.sh olimex-lpc-h3131:ostest  # (using the ostest configuration for this example)
$ cd ..                         # Set up environment
$ make                          # Make NuttX.  This will produce nuttx.bin
$ mklpc.sh                      # Make the bootloader binary (nuttx.lpc)

Note

1. Make sure to set your PATH variable appropriately or use the full path to mklpc.sh in the final step.

2. You can instruct Symantec to ignore the errors and it will stop quarantining the NXP program.

3. The CRC32 logic in boards/olimex-lpc-h3131/tools doesn’t seem to work. As a result, the CRC is currently disabled in the header:

   RCS file: /cvsroot/nuttx/nuttx/boards/olimex-lpc-h3131/tools/lpchdr.c,v
   retrieving revision 1.2
   diff -r1.2 lpchdr.c
   264c264
   <   g_hdr.imagetype       = 0x0000000b;
   ---
   >   g_hdr.imagetype       = 0x0000000a;
   

Image Download to ISRAM

Assuming that you already have the FTDI driver installed*, then here is the are the steps that I use for loading new code into the LPC-H3131:

1. Create the bootloader binary, nuttx.lpc, as described above.

2. With the power off, set the boot jumpers to enable booting from UART. The boot jumpers are the block of three jumper just in-board from the JTAG connector; Jumper pair 1-2 is the pair furthest from the JTAG connector:

   • 1-2: Closed

   • 3-4: Closed

   • 5-6: Open

3. Connected the LPC-H3131 using the FTDI USB port (not the lpc3131 USB port) This will power up the LPC-H3131 and start the bootloader.

4. Start a terminal emulator (such as TeraTerm) at 115200 8NI.

5. Reset the LPC-H3131 and you should see:

   LPC31xx READY FOR PLAIN IMAGE>
   

6. Send the nuttx.lpc file and you should see “Download finished”

That will load the NuttX binary into ISRAM and attempt to execute it.

See the LPC313x documentation if you do not have the FTDI driver installed.

TeraTerm Note: This is how to send a file from TeraTerm. It is essentially step 6 exploded in more detail for the case of TeraTerm:

1. Start the ROM bootloader as described above.

2. At the LPC31xx READY FOR PLAIN IMAGE> prompt, open the File menu and select the Send File... option.

3. Select the file to send.

4. Before “Open” -ing the file MAKE SURE TO CHECK THE “Binary” BOX! This has cost me a few hours a few times because I forget to do this. The program will NOT RUN is sent non-binary.

   NO, I am not SHOUTING. I am just making sure that I never forget to do this again.

5. “Open”-ing the file will send it to the ROM bootloader.

6. You should see “Download finished” from the bootloader followed immediately by any serial console output from your program.

Using OpenOCD and GDB

Note

As of this writing, my OpenOCD script does NOT work. It fails because it is unable to halt the LPC3131. So, unfortunately, OpenOCD is not a option right now.

I have been using the Olimex ARM-USB-OCD JTAG debugger with the LPC-H3131 (http://www.olimex.com). The OpenOCD configuration file is here: tools/armusbocb.cfg. There is also a script on the tools directory that I used to start the OpenOCD daemon on my system called oocd.sh. That script would probably require some modifications to work in another environment:

• Possibly the value of OPENOCD_PATH

• If you are working under Linux you will need to change any occurrences of cygpath -w blablabla to just blablabla

Then you should be able to start the OpenOCD daemon like:

$ boards/olimex-lpc-h3131/tools/oocd.sh $PWD

Where it is assumed that you are executing oocd.sh from the top level directory where NuttX is installed.

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

And you can load the NuttX ELF file:

(gdb) symbol-file nuttx
(gdb) load nuttx

ARM/LPC-H3131-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_ARM926EJS=y

• CONFIG_ARCH_CHIP: Identifies the arch/*/chip subdirectory

  • CONFIG_ARCH_CHIP=lpc313x

• CONFIG_ARCH_CHIP_name: For use in C code

  • CONFIG_ARCH_CHIP_LPC3131

• CONFIG_ARCH_BOARD: Identifies the boards/ subdirectory and hence, the board that supports the particular chip or SoC.

  • CONFIG_ARCH_BOARD="olimex-lpc-h3131"

• CONFIG_ARCH_BOARD_name: For use in C code

  • CONFIG_ARCH_BOARD_OLIMEX_LPC_H3131

• CONFIG_ARCH_LOOPSPERMSEC: Must be calibrated for correct operation of delay loops

• CONFIG_ENDIAN_BIG: Define if big endian (default is little endian)

• CONFIG_RAM_SIZE: For most ARM9 architectures, this describes the size of installed DRAM. For the LPC313X, it is used only to determine how to map the executable regions. It is SDRAM size only if you are executing out of the external SDRAM; or it could be NOR FLASH size, external SRAM size, or internal SRAM size.

• CONFIG_RAM_START: The start address of installed DRAM (physical)

• CONFIG_RAM_VSTART: The startaddress of DRAM (virtual)

• 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_BUTTONS: Enable support for buttons. Unique to board architecture.

• CONFIG_ARCH_DMA: Support DMA initialization

• CONFIG_ARCH_LOWVECTORS: define if vectors reside at address 0x0000:00000 Undefine if vectors reside at address 0xffff:0000

• CONFIG_ARCH_ROMPGTABLE: A pre-initialized, read-only page table is available. If defined, then board-specific logic must also define PGTABLE_BASE_PADDR, PGTABLE_BASE_VADDR, and all memory section mapping in a file named board_memorymap.h.

Individual subsystems can be enabled:

• CONFIG_LPC31_MCI

• CONFIG_LPC31_SPI

• CONFIG_LPC31_UART

External memory available on the board (see also CONFIG_MM_REGIONS)

• CONFIG_LPC31_EXTSRAM0: Select if external SRAM0 is present

• CONFIG_LPC31_EXTSRAM0HEAP: Select if external SRAM0 should be configured as part of the NuttX heap.

• CONFIG_LPC31_EXTSRAM0SIZE: Size (in bytes) of the installed external SRAM0 memory

• CONFIG_LPC31_EXTSRAM1: Select if external SRAM1 is present

• CONFIG_LPC31_EXTSRAM1HEAP: Select if external SRAM1 should be configured as part of the NuttX heap.

• CONFIG_LPC31_EXTSRAM1SIZE: Size (in bytes) of the installed external SRAM1 memory

• CONFIG_LPC31_EXTDRAM: Select if external SDRAM is present

• CONFIG_LPC31_EXTDRAMHEAP: Select if external SDRAM should be configured as part of the NuttX heap.

• CONFIG_LPC31_EXTDRAMSIZE: Size (in bytes) of the installed external SDRAM memory

• CONFIG_LPC31_EXTNAND: Select if external NAND is present

• CONFIG_LPC31_EXTNANDSIZE: Size (in bytes) of the installed external NAND memory

LPC313X specific device driver settings

• CONFIG_UART_SERIAL_CONSOLE: selects the UART for the console and ttys0

• CONFIG_UART_RXBUFSIZE: Characters are buffered as received. This specific the size of the receive buffer

• CONFIG_UART_TXBUFSIZE: Characters are buffered before being sent. This specific the size of the transmit buffer

• CONFIG_UART_BAUD: The configure BAUD of the UART. Must be

• CONFIG_UART_BITS: The number of bits. Must be either 7 or 8.

• CONFIG_UART_PARTIY: 0=no parity, 1=odd parity, 2=even parity

• CONFIG_UART_2STOP: Two stop bits

Configurations

Information Common to All Configurations

Each LPC-H3131 configuration is maintained in a sub-directory and can be selected as follows:

$ tools/configure.sh olimex-lpc-h3131:<subdir>

Before building, make sure the PATH environment variable includes 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.

Note

1. These configurations use the mconf-based configuration tool. To change any of these configurations using that tool, you should:

   1. Build and install the kconfig-mconf tool. See nuttx/README.txt see additional README.txt files in the NuttX tools repository.

   2. Execute make menuconfig in nuttx/ in order to start the reconfiguration process.

2. Unless stated otherwise, all configurations generate console output on the UART0 associated with the FT232RL USB-to UART converter.

3. Unless otherwise stated, the configurations are setup for Windows undery Cygwin. This can, however, be easily reconfigured.

4. All of these configurations use the Code Sourcery for Windows toolchain (unless stated otherwise in the description of the configuration). That toolchain selection can easily be reconfigured using ‘make menuconfig’. Here are the relevant current settings:

   Build Setup:

   • CONFIG_HOST_WINDOWS=y: Microsoft Windows

   • CONFIG_WINDOWS_CYGWIN=y: Using Cygwin or other POSIX environment

   System Type -> Toolchain:

   • CONFIG_ARM_TOOLCHAIN_GNU_EABI=y: GNU EABI toolchain for windows

nsh

Configures the NuttShell (nsh) located at examples/nsh. The Configuration enables only the serial NSH interface.

General Configuration. These are easily change by modifying the NuttX configuration:

• Console on UART -> UART-to-USB converter

• Platform: Windows with Cygwin

• Toolchain: ARM EABI GCC for Windows

Note

1. Built-in applications are not supported by default. To enable NSH built-in applications:

   Binary

   • CONFIG_BUILTIN=y: Support built-in applications

   Application Configuration -> NSH Library

   • CONFIG_NSH_BUILTIN_APPS=y: Enable built-in applications

2. SDRAM support is not enabled by default. SDRAM support can be enabled by adding the following to your NuttX configuration file:

   Note

   There is still something wrong with the SDRAM setup. At present it hangs on the first access from SDRAM during configuration.

   System Type->LPC31xx Peripheral Support

   • CONFIG_LPC31_EXTDRAM=y: Enable external DRAM support

   • CONFIG_LPC31_EXTDRAMSIZE=33554432: 256Mbit -> 32Mbyte

   • CONFIG_LPC31_SDRAM_16BIT=y: Organized 16Mbit x 16 bits wide

   Now that you have SDRAM enabled, what are you going to do with it? One thing you can is add it to the heap

   System Type->Heap Configuration

   • CONFIG_LPC31_EXTDRAMHEAP=y: Add the SDRAM to the heap

   Memory Management

   • CONFIG_MM_REGIONS=2: Two memory regions: ISRAM and SDRAM

   Another thing you could do is to enable the RAM test built-in application:

3. You can enable the NuttX RAM test that may be used to verify the external SDRAM. To do this, keep the SDRAM out of the heap so that it can be tested without crashing programs using the memory.

   First enable built-in applications as described above, then make the following additional modifications to the NuttX configuration:

   System Type->Heap Configuration

   • CONFIG_LPC31_EXTDRAMHEAP=n: Don’t add the SDRAM to the heap

   Memory Management

   • CONFIG_MM_REGIONS=1: One memory regions: ISRAM

   Then enable the RAM test built-in application:

   Application Configuration->System NSH Add-Ons->Ram Test

   • CONFIG_TESTING_RAMTEST=y

   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 0x2000:0000 (DDR CS):

   nsh> ramtest -h
   Usage: ramtest [-w|h|b] <hex-address> <decimal-size>
   
   Where:
     <hex-address> starting address of the test.
     <decimal-size> number of memory locations (in bytes).
     -w Sets the width of a memory location to 32-bits.
     -h Sets the width of a memory location to 16-bits (default).
     -b Sets the width of a memory location to 8-bits.
   

   To test the entire external 256MB SRAM:

   nsh> ramtest -w 30000000 33554432
   RAMTest: Marching ones: 30000000 33554432
   RAMTest: Marching zeroes: 30000000 33554432
   RAMTest: Pattern test: 30000000 33554432 55555555 aaaaaaaa
   RAMTest: Pattern test: 30000000 33554432 66666666 99999999
   RAMTest: Pattern test: 30000000 33554432 33333333 cccccccc
   RAMTest: Address-in-address test: 30000000 33554432
   

4. This configuration has been used to test USB host functionality. USB host is not enabled by default. If you will to enable USB host support in the NSH configuration, please modify the NuttX configuration as follows:

   1. Basic USB Host support

      Drivers -> USB Host Driver Support

      • CONFIG_USBHOST=y: General USB host support

      • CONFIG_USBHOST_INT_DISABLE=n: Interrupt EPs need with hub, HID keyboard, and HID mouse

      • CONFIG_USBHOST_ISOC_DISABLE=y: Not needed (or supported)

      System Type -> Peripherals

      • CONFIG_LPC31_USBOTG=y: Enable the USB OTG peripheral

      System Type -> USB host configuration

      • CONFIG_LPC31_EHCI_BUFSIZE=128

      • CONFIG_LPC31_EHCI_PREALLOCATE=y

      RTOS Features -> Work Queue Support

      • CONFIG_SCHED_WORKQUEUE=y: High priority queue support is needed

      • CONFIG_SCHED_HPWORK=y

      • CONFIG_SCHED_HPWORKSTACKSIZE=1536 (1024 seems to work okay too)

   2. Hub Support.

      Drivers -> USB Host Driver Support

      • CONFIG_USBHOST_INT_DISABLE=n: Interrupt endpoint support needed

      • CONFIG_USBHOST_HUB=y: Enable the hub class

      • CONFIG_USBHOST_ASYNCH=y: Asynchronous I/O supported needed for hubs

      RTOS Features -> Work Queue Support

      • CONFIG_SCHED_LPWORK=y: Low priority queue support is needed

      • CONFIG_SCHED_LPNTHREADS=1

      • CONFIG_SCHED_LPWORKSTACKSIZE=1024

      Note

      1. It is necessary to perform work on the low-priority work queue (vs. the high priority work queue) because:

         1. Deferred work requires some delays and waiting, and

         2. There are dependencies between the waiting and driver interrupt related work. Since that interrupt related work will performed on the high priority work queue, there would be the likelihood of deadlocks if you wait for events on the high priority work thread that can only occur if the high priority work thread is available to post those events.

      2. Logic nesting becomes deeper with a hub and it may also be necessary to increase some stack sizes.

   3. USB Mass Storage Class. With this class enabled, you can support connection of USB FLASH storage drives. Support for the USB mass storage class is enabled like this:

      Drivers -> USB Host Driver Support

      • CONFIG_USBHOST_MSC=y: Mass storage class support

      The MSC class will work like this. When you first start NSH, you can look at the available devices like this:

      NuttShell (NSH) NuttX-6.31
      nsh> ls -l /dev
      /dev:
       crw-rw-rw-       0 console
       crw-rw-rw-       0 null
       crw-rw-rw-       0 ttyS0
      

      The crw-rw-rw- indicates a readable, write-able character device.

      nsh> ls -l /dev
      /dev:
       crw-rw-rw-       0 console
       crw-rw-rw-       0 null
       brw-rw-rw-       0 sda
       crw-rw-rw-       0 ttyS0
      

      The brw-rw-rw- indicates a readable, write-able block device. This block device can then be mounted like this:

      nsh> mount -t vfat /dev/sda /mnt/flash
      

      The USB FLASH drive contents are then visible under /mnt/flash and can be operated on with normal file system commands like:

      nsh> mount -t vfat /dev/sda /mnt/flash
      nsh> cat /mnt/flash/filec.c
      etc.
      

      It is recommended that the drive by unmounted BEFORE it is removed. That is not always possible so if the USB FLASH is removed BEFORE the drive is unmounted, the device at /dev/sda will persist in an unusable stack until it is unmounted with the following command (NOTE: If the FLASH drive is re-inserted in this state, it will appear as /dev/sdb):

      nsh> umount /mnt/flash
      

   4. HID Keyboard support. The following support will enable support for certain keyboard devices (only the so-called “boot” keyboard class is supported):

      Drivers -> USB Host Driver Support

      • CONFIG_USBHOST_HIDKBD=y: HID keyboard class support

      Drivers -> USB Host Driver Support

      • CONFIG_USBHOST_INT_DISABLE=n: Interrupt endpoint support needed

      In this case, when the HID keyboard is installed, you see a new character device called /dev/kbda.

      There is a HID keyboard test example that can be enabled with the following settings. NOTE: In this case, NSH is disabled because the HID keyboard test is a standalone test.

      This selects the HIDKBD example:

      Application Configuration -> Examples

      • CONFIG_EXAMPLES_HIDKBD=y

      • CONFIG_EXAMPLES_HIDKBD_DEVNAME="/dev/kbda"

      RTOS Features

      • CONFIG_INIT_ENTRYPOINT="hidkbd_main"

      These settings disable NSH:

      Application Configuration -> Examples

      • CONFIG_SYSTEM_NSH=n

      Application Configuration -> NSH Library

      • CONFIG_NSH_LIBRARY=y

      Using the HID Keyboard example: Anything typed on the keyboard should be echoed on the serial console. Here is some sample of a session:

      Initialization

      hidkbd_main: Register class drivers
      hidkbd_main: Initialize USB host keyboard driver
      hidkbd_main: Start hidkbd_waiter
      hidkbd_waiter: Running
      

      The test example will periodically attempt to open /dev/kbda

      Opening device /dev/kbda
      Failed: 2
      Opening device /dev/kbda
      Failed: 2
      etc.
      

      The open will fail each time because there is no keyboard attached. When a USB keyboard is attached, the open of /dev/kbda will succeed and the test will begin echoing data to the serial console:

      hidkbd_waiter: connected
      Opening device /dev/kbda
      Device /dev/kbda opened
      

      For example, this text was entered from the keyboard:

      Now is the time for all good men to come to the aid of their party.
      

      Then when the device is removed, the test will resume attempting to open the driver until the next time it is connected

      Closing device /dev/kbda: -1
      Opening device /dev/kbda
      Failed: 19
      hidkbd_waiter: disconnected
      
      Opening device /dev/kbda
      Failed: 2
      etc.
      

   4. The USB monitor can also be enabled:

   Drivers -> USB Host Driver Support

   • CONFIG_USBHOST_TRACE=y

   • CONFIG_USBHOST_TRACE_NRECORDS=128

   • CONFIG_USBHOST_TRACE_VERBOSE=y

   Application Configuration -> System Add-Ons

   • CONFIG_USBMONITOR=y

   • CONFIG_USBMONITOR_INTERVAL=1

   Note

   I have found that if you enable USB DEBUG and/or USB tracing, the resulting image requires to much memory to execute out of internal SRAM. I was able to get the configurations to run out of SRAM with debug/tracing enabled by carefully going through the configuration and reducing stack sizes, disabling unused OS features, disabling un-necessary NSH commands, etc.

5. Making the Configuration Smaller. This configuration runs out of internal SRAM. If you enable many features, then your code image may outgrow the available SRAM; even if the code can be loaded into SRAM, it may still fail at runtime due to insufficient memory.

   Since SDRAM is not currently working (see above) and NAND support has not be integrated, the only really option is to put NSH “on a diet” to reduce the size so that it will fit into memory.

   Here are a few things you can do:

   1. Try using smaller stack sizes.

   2. Disable operating system features. Here some that can go:

      • CONFIG_DISABLE_ENVIRON=y

      • CONFIG_DISABLE_MQUEUE=y

      • CONFIG_DISABLE_POSIX_TIMERS=y

      • CONFIG_DISABLE_PTHREAD=y

      • CONFIG_MQ_MAXMSGSIZE=0

      • CONFIG_NUNGET_CHARS=0

      • CONFIG_PREALLOC_MQ_MSGS=0

   3. Disable NSH commands. I can live fine without these:

      • CONFIG_NSH_DISABLE_ADDROUTE=y

      • CONFIG_NSH_DISABLE_CD=y

      • CONFIG_NSH_DISABLE_CMP=y

      • CONFIG_NSH_DISABLE_CP=y

      • CONFIG_NSH_DISABLE_DELROUTE=y

      • CONFIG_NSH_DISABLE_EXEC=y

      • CONFIG_NSH_DISABLE_EXIT=y

      • CONFIG_NSH_DISABLE_GET=y

      • CONFIG_NSH_DISABLE_HEXDUMP=y

      • CONFIG_NSH_DISABLE_IFCONFIG=y

      • CONFIG_NSH_DISABLE_LOSETUP=y

      • CONFIG_NSH_DISABLE_MB=y

      • CONFIG_NSH_DISABLE_MH=y

      • CONFIG_NSH_DISABLE_MKFIFO=y

      • CONFIG_NSH_DISABLE_MKRD=y

      • CONFIG_NSH_DISABLE_NFSMOUNT=y

      • CONFIG_NSH_DISABLE_PING=y

      • CONFIG_NSH_DISABLE_PUT=y

      • CONFIG_NSH_DISABLE_PWD=y

      • CONFIG_NSH_DISABLE_RM=y

      • CONFIG_NSH_DISABLE_RMDIR=y

      • CONFIG_NSH_DISABLE_SET=y

      • CONFIG_NSH_DISABLE_SOURCE=y

      • CONFIG_NSH_DISABLE_SLEEP=y

      • CONFIG_NSH_DISABLE_TEST=y

      • CONFIG_NSH_DISABLE_UNSET=y

      • CONFIG_NSH_DISABLE_USLEEP=y

      • CONFIG_NSH_DISABLE_WGET=y

      • CONFIG_NSH_DISABLE_XD=y