From 6cb9664b69df704788dd3672658347279534d5aa Mon Sep 17 00:00:00 2001
From: Kevin Lange <kevin.lange@dakko.us>
Date: Sun, 2 Dec 2012 23:28:29 -0800
Subject: [PATCH] Fix some VESA woes

---
 kernel/include/multiboot.h | 25 +++++++++++++++++++++++++
 kernel/include/system.h    |  1 +
 kernel/main.c              |  5 ++++-
 kernel/video/lfb.c         | 11 +++++++++++
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/kernel/include/multiboot.h b/kernel/include/multiboot.h
index 55e8f1af..53152049 100644
--- a/kernel/include/multiboot.h
+++ b/kernel/include/multiboot.h
@@ -47,6 +47,31 @@ struct multiboot
 	uintptr_t vbe_interface_len;
 } __attribute__ ((packed));
 
+typedef struct {
+	uint16_t attributes;
+	uint8_t  winA, winB;
+	uint16_t granularity;
+	uint16_t winsize;
+	uint16_t segmentA, segmentB;
+	uint32_t realFctPtr;
+	uint16_t pitch;
+
+	uint16_t Xres, Yres;
+	uint8_t  Wchar, Ychar, planes, bpp, banks;
+	uint8_t  memory_model, bank_size, image_pages;
+	uint8_t  reserved0;
+
+	uint8_t  red_mask, red_position;
+	uint8_t  green_mask, green_position;
+	uint8_t  blue_mask, blue_position;
+	uint8_t  rsv_mask, rsv_position;
+	uint8_t  directcolor_attributes;
+
+	uint32_t physbase;
+	uint32_t reserved1;
+	uint16_t reserved2;
+} __attribute__ ((packed)) vbe_info_t;
+
 struct multiboot *copy_multiboot(struct multiboot *mboot_ptr);
 void dump_multiboot(struct multiboot *mboot_ptr);
 char * ramdisk;
diff --git a/kernel/include/system.h b/kernel/include/system.h
index 34be9d5c..2ee85984 100644
--- a/kernel/include/system.h
+++ b/kernel/include/system.h
@@ -310,6 +310,7 @@ extern uint16_t lfb_resolution_x;
 extern uint16_t lfb_resolution_y;
 extern uint16_t lfb_resolution_b;
 extern uintptr_t lfb_get_address();
+extern uint8_t * lfb_vid_memory;
 
 /* BOCHS / QEMU VBE Driver */
 extern void graphics_install_bochs(uint16_t, uint16_t);
diff --git a/kernel/main.c b/kernel/main.c
index c46d6330..c31bb890 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -79,6 +79,10 @@ int main(struct multiboot *mboot, uint32_t mboot_mag, uintptr_t esp) {
 		mboot_ptr = mboot;
 		char cmdline_[1024];
 
+		if (mboot_ptr->vbe_mode_info) {
+			lfb_vid_memory = (uint8_t *)((vbe_info_t *)(mboot_ptr->vbe_mode_info))->physbase;
+		}
+
 		size_t len = strlen((char *)mboot_ptr->cmdline);
 		memmove(cmdline_, (char *)mboot_ptr->cmdline, len + 1);
 
@@ -150,7 +154,6 @@ int main(struct multiboot *mboot, uint32_t mboot_mag, uintptr_t esp) {
 		ext2_ramdisk_mount((uintptr_t)ramdisk);
 	}
 
-
 	if (!fs_root) {
 		kprintf("Nothing to do.\n");
 		while (1) {
diff --git a/kernel/video/lfb.c b/kernel/video/lfb.c
index af676818..edd98e5d 100644
--- a/kernel/video/lfb.c
+++ b/kernel/video/lfb.c
@@ -110,6 +110,16 @@ void graphics_install_preset(uint16_t w, uint16_t h) {
 	herp[0] = 0xA5ADFACE;
 	herp[1] = 0xFAF42943;
 
+	if (lfb_vid_memory) {
+		for (uintptr_t i = (uintptr_t)lfb_vid_memory; i <= (uintptr_t)lfb_vid_memory + 0xFF0000; i += 0x1000) {
+			dma_frame(get_page(i, 1, kernel_directory), 0, 1, i);
+		}
+		if (((uintptr_t *)lfb_vid_memory)[0] == 0xA5ADFACE && ((uintptr_t *)lfb_vid_memory)[1] == 0xFAF42943) {
+			debug_print(INFO, "Was able to locate video memory at 0x%x without dicking around.", lfb_vid_memory);
+			goto mem_found;
+		}
+	}
+
 	for (int i = 2; i < 1000; i += 2) {
 		herp[i]   = 0xFF00FF00;
 		herp[i+1] = 0x00FF00FF;
@@ -125,6 +135,7 @@ void graphics_install_preset(uint16_t w, uint16_t h) {
 		for (uintptr_t x = fb_offset; x < fb_offset + 0xFF0000; x += 0x1000) {
 			if (((uintptr_t *)x)[0] == 0xA5ADFACE && ((uintptr_t *)x)[1] == 0xFAF42943) {
 				lfb_vid_memory = (uint8_t *)x;
+				debug_print(INFO, "Had to futz around, but found video memory at 0x%x", lfb_vid_memory);
 				goto mem_found;
 			}
 		}