Re: [ECOS] Problems with ecosSWtools and thumb-elf

[Geir Harris Hedemark <geir@dod.no>]

jlarmour@cygnus.co.uk (Jonathan Larmour) writes:
> If you do go down that route, let the list know how you get on, and just
> ask if you have any problems. I'm sure someone should be able to help.

I did. I picked up binutils-2.9.1 and egcs-1.1.2. I compiled and
installed binutils first, then egcs. The options to configure were
--target=thumb-coff --prefix=/local/hacks/arm. For some reason there
is no elf support for thumb in binutils-2.9.1. Or was it egcs? I
forget.

1:

Since I will use this in an embedded system which will not run *nix or
even have a filesystem or a terminal, I did not have or need the
standard *.h files (stdio.h and so on). Had to define "inhibit_libc"
when compiling libgcc2.c so xgcc would not barf on some
includes. According to the code, that can lead to problems.

2:

The makefile did not find the assembler by itself, even if I was
compiling egcs with the same prefix as binutils. I had to have
thumb-coff-as in my path.

3:

The tests failed. It said:
checking whether the C compiler (/data/nova/imp/software/gnu/build-egcs/gcc/xgcc -B/data/nova/imp/software/gnu/build-egcs/gcc/ -g -O2 ) works... no
configure: error: installation or configuration problem: C compiler cannot create executables.
make: *** [configure-target-libiberty] Error 1

However, I was able to generate a .s and a .o file without
problems. If I tried to generate a a.out file directly, ld told me:

/local/hacks/arm/thumb-coff/bin/ld: cannot open crt0.o: No such file or directory
collect2: ld returned 1 exit status

I cannot find this file. However when I link things manually:

DEFAULT:
	$(cc) $(ccflags) -c boot.c
	$(ld) $(ldflags) -Map=image.map -o image.coff boot.o
	$(objcopy) --output-target=tekhex -S --verbose image.coff image.hex

it works ok, assuming I take responsibility for start points and the like.

ldflags = -O2 --cref -M -L/local/hacks/arm/thumb-coff/lib

4:

When I try to use objdump to disassemble what I have just compiled
from tekhex or binary format, I get four-byte instructions, not thumb
code. Disassembling from coff works ok, I get sensible thumb code.

Seems I have solved my most immediate problem(s), but egcs seems to
have poorer cross-target support than the ecos tools. Is this correct?

Geir