boot: Partial attempt at video mode setting in BIOS loader

boot/boot.S

@@ -59,7 +59,6 @@ unrealmode:
 	jmp _oh_no
 
 can_long:
-
 	/* Spot check memory */
 	movl $0x12345678, %eax
 	movl $0x5000000, %ebx
@@ -105,6 +104,71 @@ boot_from_cd:
 	call do_e820
 	jc hang
 
+	/* Skip video mode set */
+	jmp vbe_done
+
+	/* Get video mode info */
+	mov $0, %ax
+	mov %ax, %es
+	mov $vbe_cont_info, %di
+	mov $0x4F00, %ax
+	int $0x10
+
+	/* Now let's look at the video modes */
+	mov (vbe_cont_info_mode_seg), %ax
+	mov %ax, %fs
+	mov (vbe_cont_info_mode_off), %ax
+	mov %ax, %si
+
+	mov $vbe_info, %di
+
+vbe_loop:
+	mov %fs:(%si), %cx
+
+	mov $0xFFFF, %dx
+	cmp %cx, %dx
+	je vbe_out_of_modes
+
+	/* Check the mode */
+	mov $0x4F01, %ax
+	int $0x10
+
+	/* Is it 1024? */
+	mov $1024, %dx
+	movw (vbe_info_width), %ax
+	cmp %ax, %dx
+	jne vbe_next
+
+	/* Is it 768? */
+	mov $768, %dx
+	movw (vbe_info_height), %ax
+	cmp %ax, %dx
+	jne vbe_next
+
+	/* Is it 32 bpp? */
+	mov $32, %dl
+	movb (vbe_info_bpp), %al
+	cmp %al, %dl
+	jne vbe_next
+
+	mov %cx, %bx
+	mov $0x4F02, %ax
+	int $0x10
+
+	jmp vbe_done
+
+vbe_next:
+	add $2, %si
+	mov $0, %ax
+	mov %ax, %es
+	mov $vbe_info, %di
+	jmp vbe_loop
+
+vbe_out_of_modes:
+	movw $0x0, (vbe_info_width)
+
+vbe_done:
+
 	/* Actually switch to protected mode. */
 	mov %cr0, %eax
 	or $1, %eax
@@ -359,14 +423,66 @@ drive_params:
 drive_params_bps:
 	.word 0 /* bytes per sector */
 
+.global vbe_info
+vbe_info:
+	.word 0 /* attributes */
+	.word 0 /* old shit (window a/b) */
+	.word 0 /* Granulatory of banks, don't care. */
+	.word 0 /* Window size, don't care. */
+	.long 0 /* Segments... */
+	.long 0 /* old bank switching thing */
+.global vbe_info_pitch
+vbe_info_pitch:
+	.word 0 /* PITCH */
+.global vbe_info_width
+vbe_info_width:
+	.word 0 /* WIDTH */
+.global vbe_info_height
+vbe_info_height:
+	.word 0 /* HEIGHT */
+	.word 0 /* w, y */
+	.byte 0 /* planes */
+.global vbe_info_bpp
+vbe_info_bpp:
+	.byte 0 /* bits per pixel */
+	.byte 0 /* banks */
+	.byte 0 /* Memory model */
+	.byte 0 /* bank size */
+	.byte 0 /* pages */
+	.byte 0 /* reserved */
+	.byte 0 /* RED mask */
+	.byte 0 /* RED offset */
+	.byte 0 /* GREEN mask */
+	.byte 0 /* GREEN offset */
+	.byte 0 /* BLUE maask */
+	.byte 0 /* BLUE offset */
+	.byte 0 /* ALPHA mask */
+	.byte 0 /* ALPHA offset */
+	.byte 0 /* Color attributes */
+.global vbe_info_fbaddr
+vbe_info_fbaddr:
+	.long 0 /* Framebuffer address */
+	.long 0 /* Extra memory offset */
+	.word 0 /* Extra memory size */
+	.zero 206 /* Other crap */
+
+vbe_cont_info:
+	.ascii "VBE"
+	.word 0
+	.long 0
+	.long 0 /* caps */
+vbe_cont_info_mode_off:
+	.word 0 /* MODES */
+vbe_cont_info_mode_seg:
+	.word 0
+	.zero 494
+
 str_Bad:
 	.asciz "The boot disk does not seem to be a CD."
 str_Need_long:
 	.asciz "ToaruOS 2.0 requires a 64-bit processor."
 str_More_mem:
 	.asciz "ToaruOS 2.0 needs at least 128MiB of RAM, and 1GiB is recommended."
-str_Out_of_modes:
-	.asciz "Out of display modes"
 
 .global disk_space
 disk_space:

boot/multiboot.c

@@ -657,6 +657,19 @@ done:
 
 	multiboot_header.cmdline = (uintptr_t)cmdline;
 
+extern uint32_t *vbe_info_fbaddr;
+extern uint16_t vbe_info_pitch;
+extern uint16_t vbe_info_width;
+extern uint16_t vbe_info_height;
+extern uint8_t vbe_info_bpp;
+	if (vbe_info_width) {
+		multiboot_header.framebuffer_addr   = (uint32_t)vbe_info_fbaddr;
+		multiboot_header.framebuffer_pitch  = vbe_info_pitch;
+		multiboot_header.framebuffer_width  = vbe_info_width;
+		multiboot_header.framebuffer_height = vbe_info_height;
+		multiboot_header.framebuffer_bpp    = vbe_info_bpp;
+	}
+
 	print("Loading kernel from 0x"); print_hex((uint32_t)kernel_load_start); print("... ");
 	if (!load_kernel()) {
 		print_("Failed to load kernel.\n");

boot/platform.c

@@ -121,5 +121,4 @@ try_again:
 }
 
 
-
 #endif

boot/text.c

@@ -5,17 +5,23 @@ int txt_debug = 0;
 #ifdef EFI_PLATFORM
 #include <efi.h>
 extern EFI_SYSTEM_TABLE *ST;
+#else
+#include <stdint.h>
+#endif
 
 #include "../apps/terminal-font.h"
-
 #define char_height LARGE_FONT_CELL_HEIGHT
 #define char_width  LARGE_FONT_CELL_WIDTH
 
-EFI_GRAPHICS_OUTPUT_PROTOCOL * GOP;
-
 static int offset_x = 0;
 static int offset_y = 0;
 
+static void write_char(int x, int y, int val, int attr);
+
+#ifdef EFI_PLATFORM
+
+EFI_GRAPHICS_OUTPUT_PROTOCOL * GOP;
+
 static EFI_GUID efi_graphics_output_protocol_guid =
   {0x9042a9de,0x23dc,0x4a38,  {0x96,0xfb,0x7a,0xde,0xd0,0x80,0x51,0x6a}};
 
@@ -46,6 +52,69 @@ no_graphics:
 	return 1;
 }
 
+static void set_point(int x, int y, uint32_t color) {
+	((uint32_t *)GOP->Mode->FrameBufferBase)[(x + offset_x) + (y + offset_y) * GOP->Mode->Info->PixelsPerScanLine] = color;
+}
+void clear_() {
+	x = 0;
+	y = 0;
+	memset((void*)GOP->Mode->FrameBufferBase,0,GOP->Mode->FrameBufferSize);
+}
+
+static void placech(unsigned char c, int x, int y, int attr) {
+	write_char(x * char_width, y * char_height, c, attr);
+}
+
+#else
+extern uint32_t *vbe_info_fbaddr;
+extern uint16_t vbe_info_pitch;
+extern uint16_t vbe_info_width;
+extern uint16_t vbe_info_height;
+extern uint8_t vbe_info_bpp;
+
+void init_graphics(void) {
+	offset_x = (vbe_info_width - 80 * char_width) / 2;
+	offset_y = (vbe_info_height - 24 * char_height) / 2;
+}
+
+static void set_point(int x, int y, uint32_t color) {
+	if (vbe_info_bpp == 24) {
+		*((uint8_t*)vbe_info_fbaddr + (x + offset_x) * 3 + (y + offset_y) * (vbe_info_pitch))     = (color >> 0) & 0xFF;
+		*((uint8_t*)vbe_info_fbaddr + (x + offset_x) * 3 + (y + offset_y) * (vbe_info_pitch) + 1) = (color >> 8) & 0xFF;
+		*((uint8_t*)vbe_info_fbaddr + (x + offset_x) * 3 + (y + offset_y) * (vbe_info_pitch) + 2) = (color >> 16) & 0xFF;
+	} else if (vbe_info_bpp == 32) {
+		vbe_info_fbaddr[(x + offset_x) + (y + offset_y) * (vbe_info_pitch / 4)] = color;
+	}
+}
+
+static unsigned short * textmemptr = (unsigned short *)0xB8000;
+
+static void placech_vga(unsigned char c, int x, int y, int attr) {
+	unsigned short *where;
+	unsigned att = attr << 8;
+	where = textmemptr + (y * 80 + x);
+	*where = c | att;
+}
+
+static void placech(unsigned char c, int x, int y, int attr) {
+	vbe_info_width ? write_char(x * char_width, y * char_height, c, attr) : placech_vga(c,x,y,attr);
+}
+
+void clear_() {
+	x = 0;
+	y = 0;
+	if (vbe_info_width) {
+		memset(vbe_info_fbaddr, 0, vbe_info_pitch * vbe_info_height);
+	} else {
+		for (int y = 0; y < 24; ++y) {
+			for (int x = 0; x < 80; ++x) {
+				placech_vga(' ', x, y, 0x00);
+			}
+		}
+	}
+}
+#endif
+
 static uint32_t term_colors[] = {
 	0xFF000000,
 	0xFFCC0000,
@@ -71,10 +140,6 @@ char vga_to_ansi[] = {
 	8,12,10,14, 9,13,11,15
 };
 
-static void set_point(int x, int y, uint32_t color) {
-
-	((uint32_t *)GOP->Mode->FrameBufferBase)[(x + offset_x) + (y + offset_y) * GOP->Mode->Info->PixelsPerScanLine] = color;
-}
 
 static void write_char(int x, int y, int val, int attr) {
 	if (val > 128) {
@@ -96,37 +161,6 @@ static void write_char(int x, int y, int val, int attr) {
 	}
 }
 
-static void placech(unsigned char c, int x, int y, int attr) {
-	write_char(x * char_width, y * char_height, c, attr);
-}
-
-void clear_() {
-	x = 0;
-	y = 0;
-	memset((void*)GOP->Mode->FrameBufferBase,0,GOP->Mode->FrameBufferSize);
-}
-
-#else
-
-static unsigned short * textmemptr = (unsigned short *)0xB8000;
-
-static void placech(unsigned char c, int x, int y, int attr) {
-	unsigned short *where;
-	unsigned att = attr << 8;
-	where = textmemptr + (y * 80 + x);
-	*where = c | att;
-}
-
-void clear_() {
-	x = 0;
-	y = 0;
-	for (int y = 0; y < 24; ++y) {
-		for (int x = 0; x < 80; ++x) {
-			placech(' ', x, y, 0x00);
-		}
-	}
-}
-#endif
 
 int x = 0;
 int y = 0;