README
======

README for NuttX port to the LPC4370-Link2 board featuring the NXP
LPC4370FET100 MCU - The port was derived from the LPC4370-Link2 board NuttX
port.

Contents
========

- LPC4370-Link2 development board
- Status
- Development Environment
- GNU Toolchain Options
- IDEs
- Code Red IDE/Tools
Booting the LPCLink
Using GDB
Troubleshooting
Command Line Flash Programming
Executing from SPIFI
USB DFU Booting
- NuttX EABI "buildroot" Toolchain
- NuttX OABI "buildroot" Toolchain
- NXFLAT Toolchain
- LED and Pushbuttons
- Serial Console
- FPU
- LPC4370-Link2 Configuration Options
- Configurations
- STATUS

LPC4370-Link2 board
=================

Memory Map
----------

Block Start Length
Name Address
--------------------- ---------- ------
RAM 0x10000000 128K
RAM2 0x10080000 72K
RAMAHB 0x20000000 32K
RAMAHB2 0x20008000 16K
RAMAHB3 0x2000c000 16K
RAMM0 0x18000000 16K
RAMM01 0x18004000 2K
SPIFI flash 0x14000000 1024K

Console
-------

The LPC4370-Link2 default console is the USART2.

Status
======

This is the current status of the LPC43xx port:

- The basic OS test configuration and the basic NSH configurations
are present and fully verified. This includes: SYSTICK system time,
pin and GPIO configuration, and serial console support. A SPIFI
MTD driver is also in place but requires further verification.

- The following drivers have been copied from the LPC17xx port, but
require integration into the LPC43xx. This integration should
consist of:

- Remove LPC17xx power, clocking, and pin configuration logic.
- Adding of clock source and frequency to the board.h file.
- Adding of LPC43 clock connection and pin configuration logic.

Within any luck, these drivers should come up very quickly:

- lpc43_adc.c,
- lpc43_dac.c,
- lpc43_gpdma.c,
- lpc43_i2c.c,
- lpc43_spi.c, and
- lpc43_ssp.c

These LPC17xx drivers were not brought into the LPC43xx port because
it appears that these peripherals have been completely redesigned:

- CAN,
- Ethernet,
- USB device, and
- USB host.

The following LPC43xx peripherals are unsupported. Some may be
compatible with the LPC17xx, but there is no LPC17xx driver to be
ported:

- SD/MMC,
- EMC,
- USB0,
- USB1,
- Ethernet,
- LCD,
- SCT,
- Timers 0-3
- MCPWM,
- QEI,
- Alarm timer,
- WWDT,
- RTC,
- Event monitor, and
- CAN,

For the missing drivers some of these can be leveraged from other
MCUs that appear to support the same peripheral IP.

- USB0 appears to be the same as the USB OTG peripheral for the
LPC31xx. It should be possible to drop in the LPC31xx driver
with a small porting effort.

- The Ethernet block looks to be based on the same IP as the
STM32 Ethernet and, as a result, it should be possible to leverage
the STM32 Ethernet driver with a little more effort.

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 Code Red GNU toolchain,
2. The CodeSourcery GNU toolchain,
3. The Atollic Toolchain,
4. The devkitARM GNU toolchain,
5. 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 toolchain, you simply need add one of the
following configuration options to your .config (or defconfig) file:

CONFIG_ARMV7M_TOOLCHAIN_CODEREDW=y : Code Red "RedSuite" under Windows
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery under Windows
CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYL=y : CodeSourcery under Linux
CONFIG_ARMV7M_TOOLCHAIN_ATOLLIC=y : The Atollic toolchain under Windows
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 Code Red, CodeSourcery (for Windows), Atollic and devkitARM toolchains
are Windows native toolchains. The CodeSourcery (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.

The CodeSourcery Toolchain (2009q1)
-----------------------------------
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.

The Atollic "Pro" and "Lite" Toolchain
--------------------------------------
One problem that I had with the Atollic toolchains is that the provide a gcc.exe
and g++.exe in the same bin/ file as their ARM binaries. If the Atollic bin/ path
appears in your PATH variable before /usr/bin, then you will get the wrong gcc
when you try to build host executables. This will cause to strange, uninterpretable
errors build some host binaries in tools/ when you first make.

Also, the Atollic toolchains are the only toolchains that have built-in support for
the FPU in these configurations. If you plan to use the Cortex-M4 FPU, you will
need to use the Atollic toolchain for now. See the FPU section below for more
information.

The Atollic "Lite" Toolchain
----------------------------
The free, "Lite" version of the Atollic toolchain does not support C++ nor
does it support ar, nm, objdump, or objdcopy. If you use the Atollic "Lite"
toolchain, you will have to set:

CONFIG_HAVE_CXX=n

In order to compile successfully. Otherwise, you will get errors like:

"C++ Compiler only available in TrueSTUDIO Professional"

The make may then fail in some of the post link processing because of some of
the other missing tools. The Make.defs file replaces the ar and nm with
the default system x86 tool versions and these seem to work okay. Disable all
of the following to avoid using objcopy:

CONFIG_RRLOAD_BINARY=n
CONFIG_INTELHEX_BINARY=n
CONFIG_MOTOROLA_SREC=n
CONFIG_RAW_BINARY=n

devkitARM
---------
The devkitARM toolchain includes a version of MSYS make. Make sure that the
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/lpc43xx,
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/common/up_vectors.S.

Code Red IDE/Tools
^^^^^^^^^^^^^^^^^^

Booting the LPCLink
-------------------

The first step is to activate the LPCLink's boot mode. Some general
instructions to do this are provided here:

http://support.code-red-tech.com/CodeRedWiki/BootingLPCLink

For my RedSuite installation path, that can be done using the following
steps in a Cygwin bash shell:

$ /cygdrive/c/code_red/RedSuite_4.2.3_379/redsuite/bin/Scripts/bootLPCXpresso.cmd winusb
Booting LPC-Link with LPCXpressoWIN.enc
Press any key to continue . . .

The same file logic can be found the less restrictive LPCXpresso package at:

/cygdrive/c/nxp/LPCXpresso_4.2.3_292/lpcxpresso/bin

(The "free" RedSuite version has a download limit of 8K; the "free" LPCXpresso
version has a download limit of 128K).

NOTE that the following alias may be defined to enter the boot mode with a
simpler command:

alias lpc43xx='${SCRIPT_BIN}/Scripts/bootLPCXpresso.cmd winusb'

You may also have to modify the PATH environment variable if your make cannot
find the tools.

$ lpc43xx
Booting LPC-Link with LPCXpressoWIN.enc
Press any key to continue . . .

Using GDB
---------

The underlying debugger within Red Suite/LPCXpresso is GDB. That GDB
used from the command line. The GDB configuration details for command
line use are on Code Red Wiki:

http://support.code-red-tech.com/CodeRedWiki/UsingGDB

and is also summarized here (see the full Wiki for additional details
and options).

The Code Red Debug Driver implements the GDB "remote" protocol to allow
connection to debug targets. To start a debug session using GDB, use
following steps:

arm-none-eabi-gdb executable.axf : Start GDB and name the debug image
target extended-remote | : Start debug driver, connect to target
load : Load image and download to target

The where is crt_emu_lpc18_43_nxp for LPC18xx and LPC43xx.
Your PATH variable should be set up so that the debug driver executable
can be found. For my installation, the driver for the LPC18xx and LPC43xx
is located at:

/cygdrive/c/code_red/RedSuite_4.2.3_379/redsuite/bin/crt_emu_lpc18_43_nxp.exe, OR
/cygdrive/c/nxp/LPCXpresso_4.2.3_292/lpcxpresso/bin/crt_emu_lpc18_43_nxp.exe

And are:

-n set information level for the debug driver. n should be 2, 3 or 4.
2 should be sufficient in most circumstances

-p is the target device to connect to and you should use
=LPC4370.

-wire= specifies the debug probe. For LPCLink on Windows 7 use
=winusb. The 128K free version only supports the LPC-Link
and RedProbe debug probes. Other JTAG interfaces are supported in
the full version.

Thus the correct invocation for the LPC4370 under Windows7 would be:

target extended-remote | crt_emu_lpc18_43_nxp -2 -pLPC4370 -wire=winusb

DDD. This command can be used to start GDB under the graphics front-end
DDD:

$ ddd --debugger arm-none-eabi-gdb nuttx &

NOTE 1: Don't forget to put the LPCLink in boot mode as described above
before starting GDB. So a typical session might look like this:

$ lpc43xx
Booting LPC-Link with LPCXpressoWIN.enc
Press any key to continue . . .

$ arm-none-eabi-gdb nuttx
(gdb) target extended-remote | crt_emu_lpc18_43_nxp -2 -pLPC4370 -wire=winusb
(gdb) load
(gdb) r
(gdb) c

NOTE 2: Don't forget to enable CONFIG_DEBUG_SYMBOLS=y in your NuttX
configuration file when you build NuttX. That option is necessary to build
in debugging symbols.

NOTE 3: There are few things that NuttX has to do differently if you
are using a debugger. Make sure that you also set CONFIG_DEBUG_FEATURES=y. Nothing
also is needed and no debug output will be generated; but NuttX will
use CONFIG_DEBUG_FEATURES=y to mean that a debugger is attached and will deal
with certain resets and debug controls appropriately.

So you should have:

CONFIG_DEBUG_FEATURES=y
CONFIG_DEBUG_SYMBOLS=y

NOTE 4: Every time that you control-C out of the command line GDB, you
leave a copy of the Code Red debugger (crt_emu_lpc18_43_nxp) running. I
have found that if you have these old copies of the debugger running,
hen strange things can happen when start yet another copy of the
debugger (I suspect that GDB may be talking with the wrong debugger).

If you exit GDB with quit (not control-C), it seems to clean-up okay.
But I have taken to keeping a Process Explorer window open all of the
time to keep track of how many of these bad processes have been created.

NOTE 5: There is also a certain function that is causing some problems.
The very first thing that the start-up logic does is call a function
called lpc43_softreset() which resets most of the peripherals. But it
also causes some crashes... I think because the resets are causing some
interrupts.

I put a big delay in the soft reset logic between resetting and clearing
pending interrupts and that seems to help some but I am not confident
that that is a fix. I think that the real fix might be to just eliminated
this lpc43_softreset() function if we determine that it is not needed.

If you step over lpc43_softreset() after loading the coding (using the 'n'
command), then everything seems work okay.

Troubleshooting
---------------

This page provides some troubleshooting information that you can use to
verify that the LPCLink is working correctly:

http://support.code-red-tech.com/CodeRedWiki/LPCLinkDiagnostics

Command Line Flash Programming
------------------------------

The LPC18xx/LPC43xx debug driver can also be used to program the LPC43xx
flash directly from the command line. The script flash.sh that may be
found in the configs/LPC4370-Link2/scripts directory can do that with
a single command line command.

Executing from SPIFI
--------------------

By default, the configurations here assume that you are executing directly
from SRAM.

CONFIG_LPC43_BOOT_SRAM=y : Executing in SRAM
CONFIG_ARMV7M_TOOLCHAIN_CODEREDW=y : Code Red under Windows

To execute from SPIFI, you would need to set:

CONFIG_LPC43_BOOT_SPIFI=y : Executing from SPIFI
CONFIG_RAM_SIZE=(128*1024) : SRAM Bank0 size
CONFIG_RAM_START=0x10000000 : SRAM Bank0 base address
CONFIG_SPIFI_OFFSET=(512*1024) : SPIFI file system offset

To boot the LPC4370-Link2 from SPIFI the DIP switches should be 1-OFF,
2-ON, 3-ON, 4-ON (LOW LOW LOW HIGH in Table 19, MSB to LSB).

If the code in flash hard faults after reset and crt_emu_lpc18_43_nxp
can't reset the MCU, an alternative is to temporarily change switch 1
to ON and press the reset button so it enters UART boot mode. Then
change it back to OFF and reset to boot again from flash.

# Use -wire to specify the debug probe in use:
# (empty) Red Probe+
# -wire=winusb LPC-Link on Windows XP
# -wire=hid LPC-Link on Windows Vista/ Windows 7
# Add -g -4 for verbose output

crt_emu_lpc18_43_nxp -wire=hid -pLPC4370 -load-base=0x14000000
-flash-load-exec=nuttx.bin -flash-driver=LPC1850A_4350A_SPIFI.cfx

USB DFU Booting
---------------

To be provided.

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.

1. You must have already configured Nuttx in /nuttx.

cd tools
./configure.sh LPC4370-xplorer/

2. Download the latest buildroot package into

3. unpack the buildroot tarball. The resulting directory may
have versioning information on it like buildroot-x.y.z. If so,
rename /buildroot-x.y.z to /buildroot.

4. cd /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 /nuttx.

cd tools
./configure.sh lpcxpresso-lpc1768/

2. Download the latest buildroot package into

3. unpack the buildroot tarball. The resulting directory may
have versioning information on it like buildroot-x.y.z. If so,
rename /buildroot-x.y.z to /buildroot.

4. cd /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.

LED and Pushbuttons
===================

LED
---
The LPC4370-Link2 has one user-controllable LED labelled D6 controlled
by the signal LED_3V3:

LED SIGNAL MCU
D6 LED_3V3 PE_& GPIO7[7]

A low output illuminates the LED.

If CONFIG_ARCH_LEDS is defined, the LED will be controlled as follows
for NuttX debug functionality (where NC means "No Change").

-------------------------- ---------
LED
-------------------------- ---------
LED_STARTED OFF
LED_HEAPALLOCATE OFF
LED_IRQSENABLED OFF
LED_STACKCREATED ON
LED_INIRQ NC
LED_SIGNAL NC
LED_ASSERTION NC
LED_PANIC Flashing
-------------------------- ---------

If CONFIG_ARCH_LEDS is not defined, then the LEDs are completely under
control of the application. The following interfaces are then available
for application control of the LEDs:

void board_userled_initialize(void);
void board_userled(int led, bool ledon);
void board_userled_all(uint8_t ledset);

Pushbuttons
-----------
To be provided

Serial Console
==============

The LPC4370-Link2 does not have RS-232 drivers or serial connectors on board.
USART, USART2 and USART3 are available on J12 as follows:

------ ------ -----------------------
SIGNAL J12 PIN LPC4370FET256 PIN
(TFBGA256 package)
------ ------ -----------------------
U0_TXD pin 3 F6 P9_5 U0_TXD=Alt 4
U0_RXD pin 4 F9 P9_6 U0_RXD=Alt 4
U2_TXD pin 5 H8 P1_13 U1_TXD=Alt 1
U2_RXD pin 6 J8 P1_14 U1_RXD=Alt 1
U3_TXD pin 7 H8 P1_13 U1_TXD=Alt 1
U3_RXD pin 8 J8 P1_14 U1_RXD=Alt 1
------ ------ -----------------------

GND is available on J12 pins 29 and 30
5V is available on J12 pin 2
3.3v id available on J12 pin 1

FPU
===

FPU Configuration Options
-------------------------

There are two version of the FPU support built into the most NuttX Cortex-M4
ports. The current LPC43xx port support only one of these options, the "Non-
Lazy Floating Point Register Save". As a consequence, CONFIG_ARMV7M_CMNVECTOR
must be defined in *all* LPC43xx configuration files.

1. Lazy Floating Point Register Save.

This is an untested implementation that saves and restores FPU registers
only on context switches. This means: (1) floating point registers are
not stored on each context switch and, hence, possibly better interrupt
performance. But, (2) since floating point registers are not saved,
you cannot use floating point operations within interrupt handlers.

This logic can be enabled by simply adding the following to your .config
file:

CONFIG_ARCH_FPU=y

2. Non-Lazy Floating Point Register Save

Mike Smith has contributed an extensive re-write of the ARMv7-M exception
handling logic. This includes verified support for the FPU. These changes
have not yet been incorporated into the mainline and are still considered
experimental. These FPU logic can be enabled with:

CONFIG_ARCH_FPU=y
CONFIG_ARMV7M_CMNVECTOR=y

You will probably also changes to the ld.script in if this option is selected.
This should work:

-ENTRY(_stext)
+ENTRY(__start) /* Treat __start as the anchor for dead code stripping */
+EXTERN(_vectors) /* Force the vectors to be included in the output */

CFLAGS
------

Only the recent toolchains have built-in support for the Cortex-M4 FPU. You will see
the following lines in each Make.defs file:

ifeq ($(CONFIG_ARCH_FPU),y)
ARCHCPUFLAGS = -mcpu=cortex-m4 -mthumb -march=armv7e-m -mfpu=fpv4-sp-d16 -mfloat-abi=hard
else
ARCHCPUFLAGS = -mcpu=cortex-m3 -mthumb -mfloat-abi=soft
endif

Configuration Changes
---------------------

Below are all of the configuration changes that I had to make to configs/stm3240g-eval/nsh2
in order to successfully build NuttX using the Atollic toolchain WITH FPU support:

-CONFIG_ARCH_FPU=n : Enable FPU support
+CONFIG_ARCH_FPU=y

-CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : Disable the CodeSourcery toolchain
+CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=n

-CONFIG_ARMV7M_TOOLCHAIN_ATOLLIC=n : Enable the Atollic toolchains
+CONFIG_ARMV7M_TOOLCHAIN_ATOLLIC=y :

-CONFIG_INTELHEX_BINARY=y : Suppress generation FLASH download formats
+CONFIG_INTELHEX_BINARY=n : (Only necessary with the "Lite" version)

-CONFIG_HAVE_CXX=y : Suppress generation of C++ code
+CONFIG_HAVE_CXX=n : (Only necessary with the "Lite" version)

See the section above on Toolchains, NOTE 2, for explanations for some of
the configuration settings. Some of the usual settings are just not supported
by the "Lite" version of the Atollic toolchain.

LPC4370-Link2 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=lpc43xx

CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
chip:

CONFIG_ARCH_CHIP_LPC4370=y

CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.

CONFIG_ARCH_BOARD=LPC4370-Link2 (for the LPC4370-Link2 board)

CONFIG_ARCH_BOARD_name - For use in C code

CONFIG_ARCH_BOARD_LPC4370Link2=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_RAM_SIZE - Describes the installed DRAM (CPU SRAM in this case):

CONFIG_RAM_SIZE=(32*1024) (32Kb)

There is an additional 32Kb of SRAM in AHB SRAM banks 0 and 1.

CONFIG_RAM_START - The start address of installed DRAM

CONFIG_RAM_START=0x10000000

CONFIG_ARCH_FPU - The LPC43xxx supports a floating point unit (FPU)

CONFIG_ARCH_FPU=y

CONFIG_LPC43_BOOT_xxx - The startup code needs to know if the code is running
from internal FLASH, external FLASH, SPIFI, or SRAM in order to
initialize properly. Note that a boot device is not specified for
cases where the code is copied into SRAM; those cases are all covered
by CONFIG_LPC43_BOOT_SRAM.

CONFIG_LPC43_BOOT_SRAM=y : Running from SRAM (0x1000:0000)
CONFIG_LPC43_BOOT_SPIFI=y : Running from QuadFLASH (0x1400:0000)
CONFIG_LPC43_BOOT_FLASHA=y : Running in internal FLASHA (0x1a00:0000)
CONFIG_LPC43_BOOT_FLASHB=y : Running in internal FLASHA (0x1b00:0000)
CONFIG_LPC43_BOOT_CS0FLASH=y : Running in external FLASH CS0 (0x1c00:0000)
CONFIG_LPC43_BOOT_CS1FLASH=y : Running in external FLASH CS1 (0x1d00:0000)
CONFIG_LPC43_BOOT_CS2FLASH=y : Running in external FLASH CS2 (0x1e00:0000)
CONFIG_LPC43_BOOT_CS3FLASH=y : Running in external FLASH CS3 (0x1f00:0000)

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_LPC43_ADC0=y
CONFIG_LPC43_ADC1=y
CONFIG_LPC43_ATIMER=y
CONFIG_LPC43_CAN1=y
CONFIG_LPC43_CAN2=y
CONFIG_LPC43_DAC=y
CONFIG_LPC43_EMC=y
CONFIG_LPC43_ETHERNET=y
CONFIG_LPC43_EVNTMNTR=y
CONFIG_LPC43_GPDMA=y
CONFIG_LPC43_I2C0=y
CONFIG_LPC43_I2C1=y
CONFIG_LPC43_I2S0=y
CONFIG_LPC43_I2S1=y
CONFIG_LPC43_LCD=y
CONFIG_LPC43_MCPWM=y
CONFIG_LPC43_QEI=y
CONFIG_LPC43_RIT=y
CONFIG_LPC43_RTC=y
CONFIG_LPC43_SCT=y
CONFIG_LPC43_SDMMC=y
CONFIG_LPC43_SPI=y
CONFIG_LPC43_SPIFI=y
CONFIG_LPC43_SSP0=y
CONFIG_LPC43_SSP1=y
CONFIG_LPC43_TMR0=y
CONFIG_LPC43_TMR1=y
CONFIG_LPC43_TMR2=y
CONFIG_LPC43_TMR3=y
CONFIG_LPC43_USART0=y
CONFIG_LPC43_UART1=y
CONFIG_LPC43_USART2=y
CONFIG_LPC43_USART3=y
CONFIG_LPC43_USB0=y
CONFIG_LPC43_USB1=y
CONFIG_LPC43_USB1_ULPI=y
CONFIG_LPC43_WWDT=y

LPC43xx specific U[S]ART device driver settings

CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the UARTn for the
console and ttys0 (default is the USART0).
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

CONFIG_USARTn_RS485MODE - Support LPC43xx USART0,2,3 RS485 mode
ioctls (TIOCSRS485 and TIOCGRS485) to enable and disable
RS-485 mode.

LPC43xx specific CAN device driver settings. These settings all
require CONFIG_CAN:

CONFIG_CAN_EXTID - Enables support for the 29-bit extended ID. Default
Standard 11-bit IDs.
CONFIG_CAN1_BAUD - CAN1 BAUD rate. Required if CONFIG_LPC43_CAN1 is defined.
CONFIG_CAN2_BAUD - CAN1 BAUD rate. Required if CONFIG_LPC43_CAN2 is defined.
CONFIG_CAN1_DIVISOR - CAN1 is clocked at CCLK divided by this number.
(the CCLK frequency is divided by this number to get the CAN clock).
Options = {1,2,4,6}. Default: 4.
CONFIG_CAN2_DIVISOR - CAN2 is clocked at CCLK divided by this number.
(the CCLK frequency is divided by this number to get the CAN clock).
Options = {1,2,4,6}. Default: 4.
CONFIG_CAN_TSEG1 - The number of CAN time quanta in segment 1. Default: 6
CONFIG_CAN_TSEG2 = the number of CAN time quanta in segment 2. Default: 7

LPC43xx specific PHY/Ethernet device driver settings. These setting
also require CONFIG_NET and CONFIG_LPC43_ETHERNET.

CONFIG_ETH0_PHY_KS8721 - Selects Micrel KS8721 PHY
CONFIG_PHY_AUTONEG - Enable auto-negotion
CONFIG_PHY_SPEED100 - Select 100Mbit vs. 10Mbit speed.
CONFIG_PHY_FDUPLEX - Select full (vs. half) duplex

CONFIG_NET_EMACRAM_SIZE - Size of EMAC RAM. Default: 16Kb
CONFIG_NET_NTXDESC - Configured number of Tx descriptors. Default: 18
CONFIG_NET_NRXDESC - Configured number of Rx descriptors. Default: 18
CONFIG_NET_WOL - Enable Wake-up on Lan (not fully implemented).
CONFIG_NET_REGDEBUG - Enabled low level register debug. Also needs
CONFIG_DEBUG_FEATURES.
CONFIG_NET_DUMPPACKET - Dump all received and transmitted packets.
Also needs CONFIG_DEBUG_FEATURES.
CONFIG_NET_HASH - Enable receipt of near-perfect match frames.

LPC43xx USB Device Configuration

CONFIG_LPC43_USBDEV_FRAME_INTERRUPT
Handle USB Start-Of-Frame events.
Enable reading SOF from interrupt handler vs. simply reading on demand.
Probably a bad idea... Unless there is some issue with sampling the SOF
from hardware asynchronously.
CONFIG_LPC43_USBDEV_EPFAST_INTERRUPT
Enable high priority interrupts. I have no idea why you might want to
do that
CONFIG_LPC43_USBDEV_NDMADESCRIPTORS
Number of DMA descriptors to allocate in SRAM.
CONFIG_LPC43_USBDEV_DMA
Enable lpc17xx-specific DMA support
CONFIG_LPC43_USBDEV_NOVBUS
Define if the hardware implementation does not support the VBUS signal
CONFIG_LPC43_USBDEV_NOLED
Define if the hardware implementation does not support the LED output

LPC43xx USB Host Configuration

CONFIG_USBHOST_OHCIRAM_SIZE
Total size of OHCI RAM (in AHB SRAM Bank 1)
CONFIG_USBHOST_NEDS
Number of endpoint descriptors
CONFIG_USBHOST_NTDS
Number of transfer descriptors
CONFIG_USBHOST_TDBUFFERS
Number of transfer descriptor buffers
CONFIG_USBHOST_TDBUFSIZE
Size of one transfer descriptor buffer
CONFIG_USBHOST_IOBUFSIZE
Size of one end-user I/O buffer. This can be zero if the
application can guarantee that all end-user I/O buffers
reside in AHB SRAM.

Configurations
==============

Each LPC4370-Link2 configuration is maintained in a sub-directory and can be selected
as follow:

cd tools
./configure.sh LPC4370-Link2/
cd -

Where is one of the following:

nsh:
----
This configuration is the NuttShell (NSH) example at examples/nsh/.

NOTES:

1. This configuration uses the mconf-based configuration tool. To
change this configurations 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.

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

2. The project can exucute directly from SRAM with NuttX loaded by a debugger
by setting the following configuration options.

CONFIG_LPC43_BOOT_SRAM=y : Executing in SRAM
CONFIG_ARMV7M_TOOLCHAIN_CODEREDW=y : Code Red under Windows

3. To execute from SPIFI, you would need to set:

CONFIG_LPC43_BOOT_SPIFI=y : Executing from SPIFI
CONFIG_RAM_SIZE=(128*1024) : SRAM Bank0 size
CONFIG_RAM_START=0x10000000 : SRAM Bank0 base address
CONFIG_SPIFI_OFFSET=(512*1024) : SPIFI file system offset

CONFIG_MM_REGIONS should also be increased if you want to other SRAM banks
to the memory pool.

4. This configuration an also be used create a block device on the SPIFI
FLASH. CONFIG_LPC43_SPIFI=y must also be defined to enable SPIFI setup
support:

SPIFI device geometry:

CONFIG_SPIFI_OFFSET - Offset the beginning of the block driver this many
bytes into the device address space. This offset must be an exact
multiple of the erase block size (CONFIG_SPIFI_BLKSIZE). Default 0.
CONFIG_SPIFI_BLKSIZE - The size of one device erase block. If not defined
then the driver will try to determine the correct erase block size by
examining that data returned from spifi_initialize (which sometimes
seems bad).

Other SPIFI options

CONFIG_SPIFI_SECTOR512 - If defined, then the driver will report a more
FAT friendly 512 byte sector size and will manage the read-modify-write
operations on the larger erase block.
CONFIG_SPIFI_READONLY - Define to support only read-only operations.
CONFIG_SPIFI_LIBRARY - Don't use the LPC43xx ROM routines but, instead,
use an external library implementation of the SPIFI interface.
CONFIG_SPIFI_VERIFY - Verify all spifi_program() operations by reading
from the SPI address space after each write.
CONFIG_DEBUG_SPIFI_DUMP - Debug option to dump read/write buffers. You
probably do not want to enable this unless you want to dig through a
*lot* of debug output! Also required CONFIG_DEBUG_FEATURES, CONFIG_DEBUG_INFO,
and CONFIG_DEBUG_FS,

5. In my experience, there were some missing function pointers in the LPC43xx
SPIFI ROM routines and the SPIFI configuration could only be built with
CONFIG_SPIFI_LIBRARY=y. The SPIFI library is proprietary and cannot be
provided within NuttX open source repository; SPIFI library binaries can
be found on the lpcware.com website. In this build sceneario, you must
also provide the patch to the external SPIFI library be defining the make
variable EXTRA_LIBS in the top-level Make.defs file. Good luck!

6. By default the LPC4370-Link2 port is configured to run from the onboard flash
bank A at 0x1a000000. In order to achieve this, the resulting NuttX binary
will need to have a checksum computed over the vector table and then be
converted to a hex file which can then be flashed using a debugger such as
the ULINK2 through Keil.

The checksum can be computed using the checksum binary provided with the
LPCXpresso IDE software suite as follows:

./checksum nuttx.bin -p LPC4370 -v

This will modify the binary file, appending the checksum to the correct place
at the end of the vector table.

The binary must now be converted to a hex file, which can be achieved using
the srec_cat utility, which is part of the SRecord package (srecord.sourceforge.net)
as follows:

srec_cat nuttx.bin -binary -offset 0x1a000000 -o nuttx.hex -intel --line-length=44

Now the hex file can be loaded using a debugger, and the code will execute from
flash.

STATUS
======

1. This configuration derives from the LPC4330 Xplorer configuration. In
many cases there have been global substitutions for naming to the
LPC4370 Link2 without corresponding updates to the technical description.
Thus all technical details should be taken with a grain of salt. GPIO
definitions may actually are remnants of the LPC4330-Xplorer that still
need clean-up.