diff options
Diffstat (limited to 'com32/lib/syslinux/shuffle_rm.c')
| -rw-r--r-- | com32/lib/syslinux/shuffle_rm.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/com32/lib/syslinux/shuffle_rm.c b/com32/lib/syslinux/shuffle_rm.c index 3ef8de7a..fd103d0f 100644 --- a/com32/lib/syslinux/shuffle_rm.c +++ b/com32/lib/syslinux/shuffle_rm.c @@ -51,7 +51,7 @@ int syslinux_shuffle_boot_rm(struct syslinux_movelist *fraglist, bool sti; } *rp; int i, rv; - uint8_t handoff_code[5*5+8*6+1+5], *p; + uint8_t handoff_code[8+5*5+8*6+1+5], *p; struct syslinux_memmap *tmap; addr_t regstub, stublen; @@ -59,11 +59,15 @@ int syslinux_shuffle_boot_rm(struct syslinux_movelist *fraglist, if (!tmap) return -1; - /* Search for a good place to put the real-mode register stub. - We prefer it as low as possible above 0x800. */ + /* + * Search for a good place to put the real-mode register stub. + * We prefer it as low as possible above 0x800. KVM barfs horribly + * if we're not aligned to a paragraph boundary, so set the alignment + * appropriately. + */ regstub = 0x800; stublen = sizeof handoff_code; - rv = syslinux_memmap_find(tmap, SMT_FREE, ®stub, &stublen); + rv = syslinux_memmap_find(tmap, SMT_FREE, ®stub, &stublen, 16); if (rv || (regstub > 0x100000 - sizeof handoff_code)) { /* @@ -74,7 +78,7 @@ int syslinux_shuffle_boot_rm(struct syslinux_movelist *fraglist, */ regstub = 0x510; /* Try the 0x5xx segment... */ stublen = sizeof handoff_code; - rv = syslinux_memmap_find(tmap, SMT_FREE, ®stub, &stublen); + rv = syslinux_memmap_find(tmap, SMT_FREE, ®stub, &stublen, 16); if (!rv && (regstub > 0x100000 - sizeof handoff_code)) rv = -1; /* No acceptable memory found */ @@ -87,6 +91,12 @@ int syslinux_shuffle_boot_rm(struct syslinux_movelist *fraglist, /* Build register-setting stub */ p = handoff_code; rp = (const struct syslinux_rm_regs_alt *)regs; + + *((uint32_t *)p) = 0xeac0220f; /* MOV CR0,EAX; JMP FAR */ + *((uint16_t *)(p+4)) = 8; /* Offset */ + *((uint16_t *)(p+6)) = regstub >> 4; /* Segment */ + p += 8; + for (i = 0; i < 6; i++) { if (i != 1) { /* Skip CS */ p[0] = 0xb8; /* MOV AX,imm16 */ @@ -111,8 +121,5 @@ int syslinux_shuffle_boot_rm(struct syslinux_movelist *fraglist, sizeof handoff_code)) return -1; - /* Convert regstub to a CS:IP entrypoint pair */ - regstub = (SEG((void *)regstub) << 16) + OFFS((void *)regstub); - return syslinux_do_shuffle(fraglist, memmap, regstub, 0, bootflags); } |