Re: arm kernel configurations

[Tom Talpey <tmtalpey@rcn.com>]

At 01:13 PM 10/30/2008, Phil Blundell wrote:
>On Thu, 2008-10-30 at 12:45 -0400, Tom Talpey wrote:
>> As above - the specs do include "--with-float=soft". I guess I'll have to
>> dig some more. Do I also need -mfloat-abi=softfp in the machine.conf like
>> some of the other arm's?
>
>I don't think so.  If I remember right, -mfloat-abi=softfp is for the
>case where you want to use hard floating point instructions (for speed)
>but still want to retain compatibility with a soft-float ABI.
>
>I wonder if something has gone wrong with your glibc configuration.  Try
>disassembling one of your binaries and see if you can find any reference
>to "wfs" or "rfs" instructions.  Also have a look in libc.so.6 itself to
>see what the syscall instructions look like: for OABI you will see
>something like "swi 0x900004", whereas for EABI it will look more like
>"mov ip, r7; mov r7, #4; swi 0; mov r7, ip".

Looks like EABI to me then, objdump -d libc.so.6 sample syscall:

0002a0c0 <kill>:
   2a0c0:       e1a0c007        mov     ip, r7
   2a0c4:       e3a07025        mov     r7, #37 ; 0x25
   2a0c8:       ef000000        svc     0x00000000
   2a0cc:       e1a0700c        mov     r7, ip
   2a0d0:       e3700a01        cmn     r0, #4096       ; 0x1000
   2a0d4:       312fff1e        bxcc    lr
   2a0d8:       eaffaa98        b       14b40 <__libc_start_main+0x248>
   2a0dc:       e1a00000        nop                     (mov r0,r0)

And no wfs/rfs at all in any binaries. Hmm, let me try the no-OABI
kernel again. Maybe I can get more status from it. Basically it would
say "Freeing init memory" then nothing more, while with-OABI it would
cruise.

Tom.