[OpenBIOS] PATCH: Fix b(do) ... b(leaves) ... b(loop)/b(+loop)

[Blue Swirl]

On 5/21/09, Mark Cave-Ayland <mark.cave-ayland at siriusit.co.uk> wrote:
> Hi everyone,
>
>  This patch fixes the b(do)...b(leaves)...b(loop)/b(+loop)
> structures by marking them as immediate rather then compile-only. Without
> this in place, the loop addresses would be calculated incorrectly which
> would cause the Fcode evaluator to jump to the wrong location for each loop
> iteration. I've confirmed that this change does not break do...leaves...loop
> in immediate mode either.
>
>  For reference, here are the test cases I used:
>
>
>  \ Test Fcode do...loop
>  \ Forth: 3 0 do i . cr loop
>  here
>  cc c,                   \ offset16
>  a8 c,                   \ 3
>  a5 c,                   \ 0
>  17 c, 00 c, 08 c,       \ b(do)
>  19 c,                   \ i
>  9d c,                   \ .
>  92 c,                   \ cr
>  15 c, ff c, fc c,       \ b(loop)
>  00 c,                   \ end
>
>  \ Test Fcode do...+loop
>  \ Forth: 10 0 do i . cr 2 +loop
>  here
>  cc c,                                   \ offset16
>  10 c, 00 c, 00 c, 00 c, 10 c,           \ b(lit) 0x10
>  a5 c,                                   \ 0
>  17 c, 00 c, 09 c,                       \ b(do)
>  19 c,                                   \ i
>  9d c,                                   \ .
>  92 c,                                   \ cr
>  a7 c,                                   \ 2
>  16 c, ff c, fb c,                       \ b(+loop)
>  00 c,                                   \ end
>
>  \ Test Fcode do...leave...loop
>  \ Forth: a 0 do i dup . 3 = if leave then loop
>  here
>  cc c,                                   \ offset16
>  10 c, 00 c, 00 c, 00 c, 0a c,           \ b(lit) 0xA
>  a5 c,                                   \ 0
>  17 c, 00 c, 0f c,                       \ b(do)
>  19 c,                                   \ i
>  47 c,                                   \ dup
>  9d c,                                   \ .
>  a8 c,                                   \ 3
>  3c c,                                   \ =
>  14 c, 00 c, 04 c,                       \ b?branch
>  1b c,                                   \ b(leave)
>  b2 c,                                   \ b(>resolve)
>  15 c, ff c, f5 c,                       \ b(loop)
>  00 c,                                   \ end
>
>
>  With these last 2 patches and diag-switch? set to true, the Fcode evaluator
> will now finish executing my SPARC64 disk image without crashing giving the
> following output:
>
>
>  OpenBIOS for Sparc64
>  Configuration device id QEMU version 1 machine id 0
>  CPUs: 1 x SUNW,UltraSPARC-II
>  UUID: 00000000-0000-0000-0000-000000000000
>  Welcome to OpenBIOS v1.0 built on May 21 2009 19:09
>   Type 'help' for detailed information
>
>  [sparc64] Booting file 'disk' with parameters ''
>  Not a bootable ELF image
>  Not a Linux kernel image
>  Not a bootable a.out image
>  Loading FCode image...
>  Loaded 5936 bytes
>  entry point is 0x4000
>  Evaluating FCode...
>  reserved fcode word.
>  Loading package 1.4 04 Aug 1995 13:02:54.
>  reserved fcode word.
>  reserved fcode word.
>  reserved fcode word.
>  FCode UFS Reader 1.12 00/07/17 15:48:16.
>  Loading: /platform//ufsboot
>  Loading: /platform/sun4u/ufsboot
>  Boot load failed.
>
>  byte-load: stack overflow, diff -2
>
>  0 >

Nice progress. marTux 0.2 still crashes at the same point:
entry point is 0x4000
Evaluating FCode...
reserved fcode word.
Loading package 1.4 04 Aug 1995 13:02:54.
reserved fcode word.
reserved fcode word.
reserved fcode word.
FCode UFS Reader 1.13 05/06/08 08:30:31.
Unhandled Exception 0x0000000000000034
PC = 0x00000000ffd0e370 NPC = 0x00000000ffd0e374
Stopping execution

I still applied this (r492), thanks.