diff options
Diffstat (limited to 'com32/lib/sys/vesa/initvesa.c')
| -rw-r--r-- | com32/lib/sys/vesa/initvesa.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/com32/lib/sys/vesa/initvesa.c b/com32/lib/sys/vesa/initvesa.c index 35084449..febb5804 100644 --- a/com32/lib/sys/vesa/initvesa.c +++ b/com32/lib/sys/vesa/initvesa.c @@ -105,6 +105,7 @@ static int vesacon_set_mode(void) debug("Hello, World!\r\n"); memset(&rm, 0, sizeof rm); + memset(gi, 0, sizeof *gi); gi->signature = VBE2_MAGIC; /* Get VBE2 extended data */ rm.eax.w[0] = 0x4F00; /* Get SVGA general information */ @@ -116,9 +117,13 @@ static int vesacon_set_mode(void) return 1; /* Function call failed */ if ( gi->signature != VESA_MAGIC ) return 2; /* No magic */ +#if 1 + /* Linear frame buffer is a VBE 2.0 feature. In theory this + test is redundant given that we check the bitmasks. */ if ( gi->version < 0x0200 ) { return 3; /* VESA 2.0 not supported */ } +#endif /* Copy general info */ memcpy(&__vesa_info.gi, gi, sizeof *gi); @@ -131,6 +136,7 @@ static int vesacon_set_mode(void) while ((mode = *mode_ptr++) != 0xFFFF) { debug("Found mode: 0x%04x\r\n", mode); + memset(mi, 0, sizeof *mi); rm.eax.w[0] = 0x4F01; /* Get SVGA mode information */ rm.ecx.w[0] = mode; rm.edi.w[0] = OFFS(mi); @@ -145,8 +151,16 @@ static int vesacon_set_mode(void) mi->mode_attr, mi->h_res, mi->v_res, mi->bpp, mi->memory_layout, mi->rpos, mi->gpos, mi->bpos); - /* Must be an LFB color graphics mode supported by the hardware */ - if ( (mi->mode_attr & 0x0099) != 0x0099 ) + /* Must be an LFB color graphics mode supported by the hardware. + + The bits tested are: + 7 - linear frame buffer available + 4 - graphics mode + 3 - color mode + 1 - mode information available (mandatory in VBE 1.2+) + 0 - mode supported by hardware + */ + if ( (mi->mode_attr & 0x009b) != 0x009b ) continue; /* Must be 640x480, 32 bpp */ |