Forwarding http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=541535
First, I show that this can be reproduced with binutils-current checked
out from AnonCVS on 2009-10-06 on approximately 13:30 UTC, then I will
copy and paste the original problem report I submitted to Debian after
this issue (with an assembly file of mine) was reported to me by Mika
“grml.org” Prokop. My thoughts on this: congratulations on trying to
make the Intel syntax more Intel style (ljmp → JMP FAR), but you’re
a
decade (at the least) too late and are breaking a large existing codebase.
Maybe 「.intel_syntax noprefix,v=2」 style versioning should be
used?
tgl...@tglase:~ $ ~/stuff/binutils-current/bin/as -V
GNU assembler version 2.20.51 (i686-pc-linux-gnu) using BFD version (GNU
Binutils) 2.20.51.20091006
tgl...@tglase:~ $ ~/stuff/binutils-current/bin/as -o x.o testmin.s
testmin.s: Assembler messages:
testmin.s:5: Error: too many memory references for `ljmp'
1|tgl...@tglase:~ $ ~/stuff/binutils-current/bin/as -o x.o testmin2.s
testmin2.s: Assembler messages:
testmin2.s:5: Error: junk `0xF000:0xFFF0' after expression
Package: binutils
Version: 2.19.51.20090805-1
Severity: normal
First of, a totally reduced minimal testcase. Let's try it on MirBSD:
t...@herc:~ $ cat >testmin.s
.intel_syntax noprefix
.text
.code16
.globl _start
_start: ljmp 0xF000,0xFFF0
t...@herc:~ $ cc -nostdlib -Wl,--oformat,binary -Wl,-Ttext,0 testmin.s
t...@herc:~ $ hd a.out
00000000 EA F0 FF 00 F0 - |.....|
t...@herc:~ $ as -V
GNU assembler version 050707 () using BFD version 050707 20050707
This is an i386 native GNU as, targetting (here) i8086 (due to the .code16
pseudo-op) and using Intel syntax, as opposed to that cruel AT&T syntax,
which thankfully has been supported by about every i386 gas from 1999 and
later.
It fails on Debian sid though (both amd64 and i386, I only have an i386
sid schroot though):
t...@frozenfish:~ $ as testmin.s
testmin.s: Assembler messages:
testmin.s:5: Error: too many memory references for jmp'
1|t...@frozenfish:~ $ as -V
GNU assembler version 2.19.51 (i486-linux-gnu) using BFD version (GNU Binutils
for Debian) 2.19.51.20090805
Oh how great. Let's try the i386 lenny schroot.
t...@frozenfish:~ $ as testmin.s
t...@frozenfish:~ $ file a.out
a.out: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped
t...@frozenfish:~ $ objdump -d -Mintel,i8086 a.out
a.out: file format elf32-i386
Disassembly of section .text:
00000000 <_start>:
0: ea f0 ff 00 f0 jmp 0xf000:0xfff0
t...@frozenfish:~ $ as -V
GNU assembler version 2.18.0 (i486-linux-gnu) using BFD version (GNU Binutils
for Debian) 2.18.0.20080103
Cool, it works there... (objdump on BSD shows s/:/,/ otherwise the same)
Now I install binutils-doc and "info as", then I read that the syntax for
far jumps has changed. Ye gods, how am I supposed to distinguish between
these when I target gas' intel syntax? But other than that issue, which
is VERY annoying and should be reverted upstream (i.e. the "older" syntax
should still be accepted), it simply doesn't work!
* Immediate form long jumps and calls are call/ljmp $SECTION,
$OFFSET' in AT&T syntax; the Intel syntax is all/jmp far
SECTION:OFFSET'. Also, the far return instruction is ret
$STACK-ADJUST' in AT&T syntax; Intel syntax is et far
STACK-ADJUST'.
(Intersting side note, the older syntax matched AT&T more closely; this
seems to be a try to get it more close to other Intel syntax assemblers,
which per se isn't a bad thing - or would have been in 1999. Now it's too
late... especially since more recent binutils are GPLv3.)
t...@frozenfish:~ $ cat testmin2.s
.intel_syntax noprefix
.text
.code16
.globl _start
_start: jmp far 0xF000:0xFFF0
t...@frozenfish:~ $ as testmin2.s
testmin2.s: Assembler messages:
testmin2.s:5: Error: junk F000:0xFFF0' after expression
So there isn't even a way to do a JMP FAR here. (Apologies if my editor
stripped U+0060 while pasting, it's a command character and shouldn't
be used in any strings ever. Ask Markus Kuhn...)
I invoke the "I didn't do anything! (I didn't even do anything before!)"
because the aforementioned assembly source compiles fine using other ver-
sions of gas. I would like to get this fixed, as grml depends on it; it
may or may not be a bug you'd want to forward upstream.
--
Summary: amd64+i386 as: i8086 Intel syntax far jumps broken (both
variants of them)
Product: binutils
Version: 2.21 (HEAD)
Status: NEW
Severity: normal
Priority: P2
Component: gas
AssignedTo: unassigned at sources dot redhat dot com
ReportedBy: tg at mirbsd dot de
CC: bug-binutils at gnu dot org
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://sourceware.org/bugzilla/show_bug.cgi?id=10740
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
_______________________________________________
bug-binutils mailing list
bug-binutils@gnu.org
http://lists.gnu.org/mailman/listinfo/bug-binutils
