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vga: factor out vga register setup

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When enabling vbe mode qemu will setup a bunch of vga registers to make
sure the vga emulation operates in correct mode for a linear
framebuffer.  Move that code to a separate function so we can call it
from other places too.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Gerd Hoffmann 2016-04-26 15:24:18 +02:00
parent bfa0f151a5
commit 7fa5c2c5dc
1 changed files with 44 additions and 34 deletions
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78
hw/display/vga.c
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@ -644,6 +644,49 @@ static void vbe_fixup_regs(VGACommonState *s)
s->vbe_start_addr = offset / 4;
}
/* we initialize the VGA graphic mode */
static void vbe_update_vgaregs(VGACommonState *s)
{
int h, shift_control;
if (!vbe_enabled(s)) {
/* vbe is turned off -- nothing to do */
return;
}
/* graphic mode + memory map 1 */
s->gr[VGA_GFX_MISC] = (s->gr[VGA_GFX_MISC] & ~0x0c) | 0x04 |
VGA_GR06_GRAPHICS_MODE;
s->cr[VGA_CRTC_MODE] |= 3; /* no CGA modes */
s->cr[VGA_CRTC_OFFSET] = s->vbe_line_offset >> 3;
/* width */
s->cr[VGA_CRTC_H_DISP] =
(s->vbe_regs[VBE_DISPI_INDEX_XRES] >> 3) - 1;
/* height (only meaningful if < 1024) */
h = s->vbe_regs[VBE_DISPI_INDEX_YRES] - 1;
s->cr[VGA_CRTC_V_DISP_END] = h;
s->cr[VGA_CRTC_OVERFLOW] = (s->cr[VGA_CRTC_OVERFLOW] & ~0x42) |
((h >> 7) & 0x02) | ((h >> 3) & 0x40);
/* line compare to 1023 */
s->cr[VGA_CRTC_LINE_COMPARE] = 0xff;
s->cr[VGA_CRTC_OVERFLOW] |= 0x10;
s->cr[VGA_CRTC_MAX_SCAN] |= 0x40;
if (s->vbe_regs[VBE_DISPI_INDEX_BPP] == 4) {
shift_control = 0;
s->sr[VGA_SEQ_CLOCK_MODE] &= ~8; /* no double line */
} else {
shift_control = 2;
/* set chain 4 mode */
s->sr[VGA_SEQ_MEMORY_MODE] |= VGA_SR04_CHN_4M;
/* activate all planes */
s->sr[VGA_SEQ_PLANE_WRITE] |= VGA_SR02_ALL_PLANES;
}
s->gr[VGA_GFX_MODE] = (s->gr[VGA_GFX_MODE] & ~0x60) |
(shift_control << 5);
s->cr[VGA_CRTC_MAX_SCAN] &= ~0x9f; /* no double scan */
}
static uint32_t vbe_ioport_read_index(void *opaque, uint32_t addr)
{
VGACommonState *s = opaque;
@ -730,52 +773,19 @@ void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val)
case VBE_DISPI_INDEX_ENABLE:
if ((val & VBE_DISPI_ENABLED) &&
!(s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED)) {
int h, shift_control;
s->vbe_regs[VBE_DISPI_INDEX_VIRT_WIDTH] = 0;
s->vbe_regs[VBE_DISPI_INDEX_X_OFFSET] = 0;
s->vbe_regs[VBE_DISPI_INDEX_Y_OFFSET] = 0;
s->vbe_regs[VBE_DISPI_INDEX_ENABLE] |= VBE_DISPI_ENABLED;
vbe_fixup_regs(s);
vbe_update_vgaregs(s);
/* clear the screen */
if (!(val & VBE_DISPI_NOCLEARMEM)) {
memset(s->vram_ptr, 0,
s->vbe_regs[VBE_DISPI_INDEX_YRES] * s->vbe_line_offset);
}
/* we initialize the VGA graphic mode */
/* graphic mode + memory map 1 */
s->gr[VGA_GFX_MISC] = (s->gr[VGA_GFX_MISC] & ~0x0c) | 0x04 |
VGA_GR06_GRAPHICS_MODE;
s->cr[VGA_CRTC_MODE] |= 3; /* no CGA modes */
s->cr[VGA_CRTC_OFFSET] = s->vbe_line_offset >> 3;
/* width */
s->cr[VGA_CRTC_H_DISP] =
(s->vbe_regs[VBE_DISPI_INDEX_XRES] >> 3) - 1;
/* height (only meaningful if < 1024) */
h = s->vbe_regs[VBE_DISPI_INDEX_YRES] - 1;
s->cr[VGA_CRTC_V_DISP_END] = h;
s->cr[VGA_CRTC_OVERFLOW] = (s->cr[VGA_CRTC_OVERFLOW] & ~0x42) |
((h >> 7) & 0x02) | ((h >> 3) & 0x40);
/* line compare to 1023 */
s->cr[VGA_CRTC_LINE_COMPARE] = 0xff;
s->cr[VGA_CRTC_OVERFLOW] |= 0x10;
s->cr[VGA_CRTC_MAX_SCAN] |= 0x40;
if (s->vbe_regs[VBE_DISPI_INDEX_BPP] == 4) {
shift_control = 0;
s->sr[VGA_SEQ_CLOCK_MODE] &= ~8; /* no double line */
} else {
shift_control = 2;
/* set chain 4 mode */
s->sr[VGA_SEQ_MEMORY_MODE] |= VGA_SR04_CHN_4M;
/* activate all planes */
s->sr[VGA_SEQ_PLANE_WRITE] |= VGA_SR02_ALL_PLANES;
}
s->gr[VGA_GFX_MODE] = (s->gr[VGA_GFX_MODE] & ~0x60) |
(shift_control << 5);
s->cr[VGA_CRTC_MAX_SCAN] &= ~0x9f; /* no double scan */
} else {
s->bank_offset = 0;
}