Aren
/
rulimine
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

gop: Properly determine bpp and pixel masks and shifts

This commit is contained in:
mintsuki 2021-03-14 02:11:41 +01:00
parent 7950ac5997
commit d6cda61fb9
1 changed files with 68 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
stage23/drivers/gop.c
View File

@ -6,6 +6,31 @@
#include <drivers/edid.h>
#include <lib/print.h>
static uint16_t linear_masks_to_bpp(uint32_t red_mask, uint32_t green_mask,
uint32_t blue_mask, uint32_t alpha_mask) {
uint32_t compound_mask = red_mask | green_mask | blue_mask | alpha_mask;
uint16_t ret = 32;
while ((compound_mask & (1 << 31)) == 0) {
ret--;
compound_mask <<= 1;
}
return ret;
}
static void linear_mask_to_mask_shift(
uint8_t *mask, uint8_t *shift, uint32_t linear_mask) {
*shift = 0;
while ((linear_mask & 1) == 0) {
(*shift)++;
linear_mask >>= 1;
}
*mask = 0;
while ((linear_mask & 1) == 1) {
(*mask)++;
linear_mask >>= 1;
}
}
// Most of this code taken from https://wiki.osdev.org/GOP
bool init_gop(struct fb_info *ret,
@ -64,8 +89,49 @@ bool init_gop(struct fb_info *ret,
if (status)
continue;
switch (mode_info->PixelFormat) {
case PixelBlueGreenRedReserved8BitPerColor:
ret->framebuffer_bpp = 32;
ret->red_mask_size = 8;
ret->red_mask_shift = 16;
ret->green_mask_size = 8;
ret->green_mask_shift = 8;
ret->blue_mask_size = 8;
ret->blue_mask_shift = 0;
break;
case PixelRedGreenBlueReserved8BitPerColor:
ret->framebuffer_bpp = 32;
ret->red_mask_size = 8;
ret->red_mask_shift = 0;
ret->green_mask_size = 8;
ret->green_mask_shift = 8;
ret->blue_mask_size = 8;
ret->blue_mask_shift = 16;
break;
case PixelBitMask:
ret->framebuffer_bpp = linear_masks_to_bpp(
mode_info->PixelInformation.RedMask,
mode_info->PixelInformation.GreenMask,
mode_info->PixelInformation.BlueMask,
mode_info->PixelInformation.ReservedMask);
linear_mask_to_mask_shift(&ret->red_mask_size,
&ret->red_mask_shift,
mode_info->PixelInformation.RedMask);
linear_mask_to_mask_shift(&ret->green_mask_size,
&ret->green_mask_shift,
mode_info->PixelInformation.GreenMask);
linear_mask_to_mask_shift(&ret->blue_mask_size,
&ret->blue_mask_shift,
mode_info->PixelInformation.BlueMask);
break;
default:
panic("gop: Invalid PixelFormat");
}
if (mode_info->HorizontalResolution != target_width
|| mode_info->VerticalResolution != target_height)
|| mode_info->VerticalResolution != target_height
|| ret->framebuffer_bpp != target_bpp)
continue;
print("gop: Found matching mode %x, attempting to set...\n", i);
@ -80,16 +146,9 @@ bool init_gop(struct fb_info *ret,
ret->memory_model = 0x06;
ret->framebuffer_addr = gop->Mode->FrameBufferBase;
ret->framebuffer_pitch = (gop->Mode->Info->PixelsPerScanLine * 4);
ret->framebuffer_pitch = gop->Mode->Info->PixelsPerScanLine * 4;
ret->framebuffer_width = gop->Mode->Info->HorizontalResolution;
ret->framebuffer_height = gop->Mode->Info->VerticalResolution;
ret->framebuffer_bpp = 32;
ret->red_mask_size = 8;
ret->red_mask_shift = 16;
ret->green_mask_size = 8;
ret->green_mask_shift = 8;
ret->blue_mask_size = 8;
ret->blue_mask_shift = 0;
return true;
}