Using newlib-nano libraries with LPCXpresso

[dinau]

Hi, all

I've been successful to use the newlib-nano libraries with LPCXpresso compiler (GCC_CR).
This is highly experimental,
but some simple example programs ("ticker" and "basic") work well at this moment.

1. First, needed for the newlib-nano libraries included in
   Launchpad GCC
   https://launchpad.net/gcc-arm-embedded
   I'm using Ver.4.7-2013q2.
2. Copy the newlib-nano libraries to the library folder of LPCXpresso.
   Assume that Launchpad GCC root folder name is "launchpad-gcc-root" and
   LPCXpresso root folder name is "lpxpresso-root".

(1) nano.specs file
[copy] launchpad-gcc-root/arm-none-eabi/armv7-m/nano.specs
[to] lpcxpresso-root/lpcxpresso/tools/arm-none-eabi/lib/

(2) Each libraries
i.e. for Cortex-M3 micros
[copy] launchpad-gcc-root/arm-none-eabi/lib/armv7-m/*_s.a
[to] lpcxpresso-root/lpcxpresso/tools/arm-none-eabi/lib/armv7-m/

i.e. for Cortex-M0 micros
[copy] launchpad-gcc-root/arm-none-eabi/lib/armv6-m/*_s.a
[to] lpcxpresso-root/lpcxpresso/tools/arm-none-eabi/lib/armv6-m/

Adding "--specs=nano.specs" option to the linker script option.

[workspace_tools/toolchains/gcc.py]:

    class GCC_CR(GCC):
        def __init__(self, target, options=None, notify=None):
            GCC.__init__(self, target, options, notify, GCC_CR_PATH)

            additional_compiler_flags = [
                "-D__NEWLIB__", "-D__CODE_RED", "-D__USE_CMSIS", "-DCPP_USE_HEAP",
            ]
            self.cc += additional_compiler_flags
            self.cppc += additional_compiler_flags
            if "nanolib" in self.options:
                # Use latest gcc nanolib
                self.ld.append("--specs=nano.specs")
                if target.name in ["LPC1768"]:
                    self.ld.extend(["-u", "_printf_float", "-u", "_scanf_float"])
            self.ld += ["-nostdlib"]

Building "basic" test program with newlib-nano libraries

    $ workspace_tools/build.py -m LPC1768 -t GCC_CR
    $ workspace_tools/make.py  -m LPC1768 -t GCC_CR -d. -p 0 -o nanolib

dinau