static int bios_probe(void)
{
u8 mode;
#ifdef _WAKEUP
u8 saved_mode = 0x03;
#else
u8 saved_mode = boot_params.screen_info.orig_video_mode;
#endif
u16 crtc;
struct mode_info *mi;
int nmodes = 0;
if (adapter != ADAPTER_EGA && adapter != ADAPTER_VGA)
return 0;
set_fs(0);
crtc = vga_crtc();
video_bios.modes = GET_HEAP(struct mode_info, 0);
for (mode = 0x14; mode <= 0x7f; mode++) {
if (!heap_free(sizeof(struct mode_info)))
break;
if (mode_defined(VIDEO_FIRST_BIOS+mode))
continue;
if (set_bios_mode(mode))
continue;
/* Try to verify that it's a text mode. */
/* Attribute Controller: make graphics controller disabled */
if (in_idx(0x3c0, 0x10) & 0x01)
continue;
/* Graphics Controller: verify Alpha addressing enabled */
if (in_idx(0x3ce, 0x06) & 0x01)
continue;
/* CRTC cursor location low should be zero(?) */
if (in_idx(crtc, 0x0f))
continue;
mi = GET_HEAP(struct mode_info, 1);
mi->mode = VIDEO_FIRST_BIOS+mode;
mi->depth = 0; /* text */
mi->x = rdfs16(0x44a);
mi->y = rdfs8(0x484)+1;
nmodes++;
}
set_bios_mode(saved_mode);
return nmodes;
}
void main(void)
{
/* First, copy the boot header into the "zeropage" */
copy_boot_params();
/* End of heap check */
if (boot_params.hdr.loadflags & CAN_USE_HEAP) {
heap_end = (char *)(boot_params.hdr.heap_end_ptr
+0x200-STACK_SIZE);
} else {
/* Boot protocol 2.00 only, no heap available */
puts("WARNING: Ancient bootloader, some functionality "
"may be limited!\n");
}
/* Make sure we have all the proper CPU support */
if (validate_cpu()) {
puts("Unable to boot - please use a kernel appropriate "
"for your CPU.\n");
die();
}
/* Tell the BIOS what CPU mode we intend to run in. */
set_bios_mode();
/* Detect memory layout */
detect_memory();
/* Set keyboard repeat rate (why?) */
keyboard_set_repeat();
/* Set the video mode */
set_video();
/* Query MCA information */
query_mca();
/* Voyager */
#ifdef CONFIG_X86_VOYAGER
query_voyager();
#endif
/* Query Intel SpeedStep (IST) information */
query_ist();
/* Query APM information */
#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
query_apm_bios();
#endif
/* Query EDD information */
#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
query_edd();
#endif
/* Do the last things and invoke protected mode */
go_to_protected_mode();
}
static int bios_set_mode(struct mode_info *mi)
{
return set_bios_mode(mi->mode - VIDEO_FIRST_BIOS);
}
