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kernel
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use absolute not relative disk read/writes; 

fix for syslinux DOS installer
partial fix, still need to confirm if other uses should also be absolute
This commit is contained in:
KJD 2014-07-03 20:06:47 -04:00
parent ed05c9231c
commit ed84760c0e
1 changed files with 18 additions and 4 deletions
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22
kernel/dsk.c
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@ -496,6 +496,7 @@ STATIC WORD IoctlQueblk(rqptr rp, ddt * pddt)
return failure(E_CMD);
}
/* read/write block with CHS based off start of drive's partition */
STATIC COUNT Genblockio(ddt * pddt, UWORD mode, WORD head, WORD track,
WORD sector, WORD count, VOID FAR * buffer)
{
@ -508,6 +509,19 @@ STATIC COUNT Genblockio(ddt * pddt, UWORD mode, WORD head, WORD track,
pddt->ddt_offset + sector, count, &transferred);
}
/* read/write block with CHS based off start of disk drive is on */
STATIC COUNT GenblockioAbs(ddt * pddt, UWORD mode, WORD head, WORD track,
WORD sector, WORD count, VOID FAR * buffer)
{
UWORD transferred;
/* apparently sector is ZERO, not ONE based !!! */
return LBA_Transfer(pddt, mode, buffer,
((ULONG) track * pddt->ddt_bpb.bpb_nheads + head) *
(ULONG) pddt->ddt_bpb.bpb_nsecs +
sector, count, &transferred);
}
STATIC WORD Genblkdev(rqptr rp, ddt * pddt)
{
int ret;
@ -546,10 +560,10 @@ STATIC WORD Genblkdev(rqptr rp, ddt * pddt)
/*pbpb->bpb_nsector = gblp->gbio_nsecs; */
break;
}
case 0x41: /* write track */
case 0x41: /* write track - CHS is absolute not relative to partition start */
{
struct gblkrw FAR *rw = rp->r_rw;
ret = Genblockio(pddt, LBA_WRITE, rw->gbrw_head, rw->gbrw_cyl,
ret = GenblockioAbs(pddt, LBA_WRITE, rw->gbrw_head, rw->gbrw_cyl,
rw->gbrw_sector, rw->gbrw_nsecs, rw->gbrw_buffer);
if (ret != 0)
return dskerr(ret);
@ -719,10 +733,10 @@ STATIC WORD Genblkdev(rqptr rp, ddt * pddt)
/*gblp->gbio_nsecs = pbpb->bpb_nsector; */
break;
}
case 0x61: /* read track */
case 0x61: /* read track - CHS is absolute on disk not relative to start of partition */
{
struct gblkrw FAR *rw = rp->r_rw;
ret = Genblockio(pddt, LBA_READ, rw->gbrw_head, rw->gbrw_cyl,
ret = GenblockioAbs(pddt, LBA_READ, rw->gbrw_head, rw->gbrw_cyl,
rw->gbrw_sector, rw->gbrw_nsecs, rw->gbrw_buffer);
if (ret != 0)
return dskerr(ret);