What's the difference between m68k-coff and m68k-elf ABI?

[Alex Holland]

I recently built 68k cross-compilers for coff, a.out, and elf 
output formats hosted under Cygwin. I started with ELF 
because  it seemed to be the most capable (e.g. there seemed to 
be more compiler extensions that only worked with ELF,  it was completely 
flexible in allowing one to create, name, and locate sections, 
etc.).  It also seems to be evolving into the preferred 
format of most tool chains for 32 bit processors. However, I realized too 
late that no ICE or other debug tool that I could find (except for GDB) 
supported this format for the 68K. However, all debug 
tools that I looked at supported it for more modern processors. Next, I went to 
COFF and did not notice much difference for what I was doing. Almost the same 
linker script worked and I had to change my startup code a little. However, I am 
using my own startup code and (simplified) C runtime libraries. I am using 
libgcc. I also tried a.out because one particular ICE only supported 
this format. However, this format caused me lots of grief. It gives you no 
capability to name and locate special sections. I had to change my linker script 
and my startup code significantly, and source level debugging was 
crippled.
 
Also, I have not had much luck using objcopy  to go 
from ELF to COFF, a.out, or IEEE695. The copy might complete, but the 
result would not be accepted by the particular ICE I was testing, while a direct 
output of the compiler generally would.  
 
Alex

  ----- Original Message ----- 
  From: 
  clifftsai 
  To: crossgcc 
  Sent: Monday, January 15, 2001 7:54 
  PM
  Subject: What's the difference between 
  m68k-coff and m68k-elf ABI?
  
  Hi:
      When I build the m68k cross development 
  according
        Instructions from 
  Cygnus's Website.The instrucions tell
      us to build m68k tool as 
  m68k-coff.
      But when I look into the 
  glibc/sysdeps/m68k/elf.
      The Start.s is for m68k-elf ABI.Why?How 
  about Start.s
      for coff.
      And if I use 
  m68k-coff or m68k-arm,what should I modified?
      
      Thanks 
      
Cliff