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CRTC register write protection fix - line_compare, multi_scan and double_scan fixes

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git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1127 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard 2004-11-07 22:57:20 +00:00
parent 9bb34eac8b
commit f6c958c865
1 changed files with 15 additions and 17 deletions
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32
hw/vga.c
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@ -344,7 +344,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)
printf("vga: write CR%x = 0x%02x\n", s->cr_index, val);
#endif
/* handle CR0-7 protection */
if ((s->cr[11] & 0x80) && s->cr_index <= 7) {
if ((s->cr[0x11] & 0x80) && s->cr_index <= 7) {
/* can always write bit 4 of CR7 */
if (s->cr_index == 7)
s->cr[7] = (s->cr[7] & ~0x10) | (val & 0x10);
@ -1346,11 +1346,13 @@ static void vga_draw_graphic(VGAState *s, int full_update)
disp_width = width;
shift_control = (s->gr[0x05] >> 5) & 3;
double_scan = (s->cr[0x09] & 0x80);
if (shift_control > 1) {
multi_scan = (s->cr[0x09] & 0x1f);
double_scan = (s->cr[0x09] >> 7);
if (shift_control != 1) {
multi_scan = (((s->cr[0x09] & 0x1f) + 1) << double_scan) - 1;
} else {
multi_scan = 0;
/* in CGA modes, multi_scan is ignored */
/* XXX: is it correct ? */
multi_scan = double_scan;
}
multi_run = multi_scan;
if (shift_control != s->shift_control ||
@ -1417,7 +1419,7 @@ static void vga_draw_graphic(VGAState *s, int full_update)
line_offset = s->line_offset;
#if 0
printf("w=%d h=%d v=%d line_offset=%d double_scan=0x%02x cr[0x17]=0x%02x linecmp=%d sr[0x01]=%02x\n",
printf("w=%d h=%d v=%d line_offset=%d cr[0x09]=0x%02x cr[0x17]=0x%02x linecmp=%d sr[0x01]=0x%02x\n",
width, height, v, line_offset, s->cr[9], s->cr[0x17], s->line_compare, s->sr[0x01]);
#endif
addr1 = (s->start_addr * 4);
@ -1468,21 +1470,17 @@ static void vga_draw_graphic(VGAState *s, int full_update)
}
}
if (!multi_run) {
if (!double_scan || (y & 1) != 0) {
if (y1 == s->line_compare) {
addr1 = 0;
} else {
mask = (s->cr[0x17] & 3) ^ 3;
if ((y1 & mask) == mask)
addr1 += line_offset;
}
y1++;
}
mask = (s->cr[0x17] & 3) ^ 3;
if ((y1 & mask) == mask)
addr1 += line_offset;
y1++;
multi_run = multi_scan;
} else {
multi_run--;
y1++;
}
/* line compare acts on the displayed lines */
if (y == s->line_compare)
addr1 = 0;
d += linesize;
}
if (y_start >= 0) {