Hi all,
I recently did some work to compile a kernel for MMU less Atari STs.
However, I 'm having a problem with the memcpy code as it is compiled by
gcc. When copying from odd addresses, gcc produces memcpy code that tries
to access odd addresses with move.w, which is not possible on the 68000
and therefore produces address error exceptions. Below you can find the
debug output from the hatari emulator and the memcpy version I'm using (I
hope it's the most recent one). Any help would be appreciated.
Best regards,
Matthias
P.S.: I'm using the -m68000 gcc switch
========
memcpy:
1. CPU breakpoint condition(s) matched 2 times.
pc = $ae57c
CPU=$ae57c, VBL=1057, FrameCycles=10708, HBL=47, LineCycles=180, DSP=N/A
c
Returning to emulation...
cpu video_cyc= 10708 180@ 47 : $0ae57c : 4e56 0000
link a6,#0
cpu video_cyc= 10728 200@ 47 : $0ae580 : 48e7 3030
movem.l d2-d3/a2-a3,-(sp)
cpu video_cyc= 10768 16@ 48 : $0ae584 : 262e 0008
move.l 8(a6),d3
cpu video_cyc= 10784 32@ 48 : $0ae588 : 266e 000c
movea.l $c(a6),a3
cpu video_cyc= 10800 48@ 48 : $0ae58c : 242e 0010
move.l $10(a6),d2
cpu video_cyc= 10816 64@ 48 : $0ae590 : 6752
beq.s $ae5e4
cpu video_cyc= 10824 72@ 48 : $0ae592 : 0803 0000
btst #0,d3
cpu video_cyc= 10836 84@ 48 : $0ae596 : 6742
beq.s $ae5da
cpu video_cyc= 10844 92@ 48 : $0ae5da : 2443
movea.l d3,a2
cpu video_cyc= 10848 96@ 48 : $0ae5dc : 60c0
bra.s $ae59e
cpu video_cyc= 10860 108@ 48 : $0ae59e : 7002
moveq #2,d0
cpu video_cyc= 10864 112@ 48 : $0ae5a0 : b082
cmp.l d2,d0
cpu video_cyc= 10872 120@ 48 : $0ae5a2 : 6408
bcc.s $ae5ac
cpu video_cyc= 10880 128@ 48 : $0ae5a4 : 200a
move.l a2,d0
cpu video_cyc= 10884 132@ 48 : $0ae5a6 : 0800 0001
btst #1,d0
cpu video_cyc= 10896 144@ 48 : $0ae5aa : 6632
bne.s $ae5de
cpu video_cyc= 10904 152@ 48 : $0ae5de : 34db
move.w (a3)+,(a2)+
Address Error at address $12513b, PC=$ae5de
CPU=$ae5de, VBL=1057, FrameCycles=10904, HBL=48, LineCycles=152, DSP=N/A
cpureg
D0: 0016021a D1: 00000400 D2: 00000016 D3: 0016021a
D4: 001d97c8 D5: 0016021a D6: 00000400 D7: 00132ed8
A0: 00132fac A1: 00000400 A2: 0016021a A3: 0012513b
A4: 0012513b A5: 00125151 A6: 00132e8c A7: 00132e6e
USP=000456f6 ISP=00132e6e MSP=00000000 VBR=00000000
T=00 S=1 M=0 X=0 N=0 Z=0 V=0 C=0 IMASK=7
FP0: 0 FP1: 0 FP2: 0 FP3: 0
FP4: 0 FP5: 0 FP6: 0 FP7: 0
N=0 Z=0 I=0 NAN=0
prefetch 34db5582
000ae5de: 34db 5582 60c8 2003 4cdf MOVE.W (A3)+,(A2)+
next PC: 000ae5e0
m $12513b
12513B: 41 74 61 72 69 20 68 61 72 64 77 61 72 65 20 66 Atari hardware f
12514B: 6f 75 6e 64 3a 20 00 56 49 44 45 4c 20 00 53 54 ound: .VIDEL .ST
12515B: 44 4d 41 2d 53 43 53 49 20 00 54 54 5f 53 48 49 DMA-SCSI .TT_SHI
12516B: 46 54 45 52 20 00 45 58 54 44 5f 53 48 49 46 54 FTER .EXTD_SHIFT
12517B: 45 52 20 00 53 54 4e 44 5f 53 48 49 46 54 45 52 ER .STND_SHIFTER
12518B: 20 00 53 54 5f 4d 46 50 20 00 54 54 5f 4d 46 50 .ST_MFP .TT_MFP
12519B: 20 00 54 54 5f 53 43 53 49 5f 44 4d 41 20 00 45 .TT_SCSI_DMA .E
1251AB: 58 54 44 5f 44 4d 41 20 00 54 54 5f 53 43 53 49 XTD_DMA .TT_SCSI
=========
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/string.h>
void *memcpy(void *to, const void *from, size_t n)
{
void *xto = to;
size_t temp, temp1;
if (!n)
return xto;
if ((long)to & 1) {
char *cto = to;
const char *cfrom = from;
*cto++ = *cfrom++;
to = cto;
from = cfrom;
n--;
}
if (n > 2 && (long)to & 2) {
short *sto = to;
const short *sfrom = from;
*sto++ = *sfrom++;
to = sto;
from = sfrom;
n -= 2;
}
temp = n >> 2;
if (temp) {
long *lto = to;
const long *lfrom = from;
#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)
for (; temp; temp--)
*lto++ = *lfrom++;
#else
asm volatile (
" movel %2,%3\n"
" andw #7,%3\n"
" lsrl #3,%2\n"
" negw %3\n"
" jmp %%pc@(1f,%3:w:2)\n"
"4: movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
"1: dbra %2,4b\n"
" clrw %2\n"
" subql #1,%2\n"
" jpl 4b"
: "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d"
(temp1)
: "0" (lfrom), "1" (lto), "2" (temp));
#endif
to = lto;
from = lfrom;
}
if (n & 2) {
short *sto = to;
const short *sfrom = from;
*sto++ = *sfrom++;
to = sto;
from = sfrom;
}
if (n & 1) {
char *cto = to;
const char *cfrom = from;
*cto = *cfrom;
}
return xto;
}
EXPORT_SYMBOL(memcpy);
--
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