diff options
Diffstat (limited to 'sys/dev/fb/vga.c')
| -rw-r--r-- | sys/dev/fb/vga.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/sys/dev/fb/vga.c b/sys/dev/fb/vga.c index 537552a8a844..f9ef2abf3935 100644 --- a/sys/dev/fb/vga.c +++ b/sys/dev/fb/vga.c @@ -939,7 +939,7 @@ probe_adapters(void) #if !defined(VGA_NO_BIOS) && !defined(VGA_NO_MODE_CHANGE) u_char *mp; #endif - int i; + int height, i, width; /* do this test only once */ if (vga_init_done) @@ -1134,15 +1134,34 @@ probe_adapters(void) case COMP_DIFFERENT: default: /* - * Don't use the parameter table in BIOS. It doesn't - * look familiar to us. Video mode switching is allowed - * only if the new mode is the same as or based on - * the initial mode. + * Don't use the parameter table in the BIOS, since + * even the BIOS doesn't use it for the initial mode. + * Restrict the tweaked modes to (in practice) 80x50 + * from 80x25 with 400 scan lines, since the only safe + * tweak is changing the characters from 8x16 to 8x8. */ video_mode_ptr = NULL; bzero(mode_map, sizeof(mode_map)); mode_map[adp->va_initial_mode] = adpstate.regs; rows_offset = 1; + + width = height = -1; + for (i = 0; i < nitems(bios_vmode); ++i) { + if (bios_vmode[i].vi_mode == adp->va_initial_mode) { + width = bios_vmode[i].vi_width; + height = bios_vmode[i].vi_height; + break; + } + } + for (i = 0; i < nitems(bios_vmode); ++i) { + if (bios_vmode[i].vi_mode != adp->va_initial_mode && + map_mode_num(bios_vmode[i].vi_mode) == + adp->va_initial_mode && + (bios_vmode[i].vi_width != width || + bios_vmode[i].vi_height != 2 * height)) { + bios_vmode[i].vi_mode = NA; + } + } break; } } |