This commit is contained in:
Freya Murphy 2024-01-27 05:16:57 -05:00
parent eec8119eee
commit 09b4390004
Signed by: freya
GPG key ID: 744AB800E383AE52
5 changed files with 78 additions and 1 deletions

5
include/fb.h Normal file
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@ -0,0 +1,5 @@
#pragma once
#include <stdint.h>
int fb_init(uint16_t res_x, uint16_t res_y);

68
src/arch/amd64/fb.c Normal file
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@ -0,0 +1,68 @@
#include "bindings.h"
#include <stdint.h>
#include <stddef.h>
#define PREFERRED_VY 4096
#define PREFERRED_B 32
uint16_t fb_res_x = 0;
uint16_t fb_res_y = 0;
uint16_t fb_res_b = 0;
uint8_t *fb_buffer = NULL;
int fb_init(uint16_t res_x, uint16_t res_y) {
outw(0x1CE, 0x00);
uint16_t i = inw(0x1CF);
if (i < 0xB0C0 || i > 0xB0C6) {
return -1;
}
outw(0x1CF, 0xB0C4);
i = inw(0x1CF);
/* Disable VBE */
outw(0x1CE, 0x04);
outw(0x1CF, 0x00);
/* Set X resolution to 1024 */
outw(0x1CE, 0x01);
outw(0x1CF, res_x);
/* Set Y resolution to 768 */
outw(0x1CE, 0x02);
outw(0x1CF, res_y);
/* Set bpp to 32 */
outw(0x1CE, 0x03);
outw(0x1CF, PREFERRED_B);
/* Set Virtual Height to stuff */
outw(0x1CE, 0x07);
outw(0x1CF, PREFERRED_VY);
/* Re-enable VBE */
outw(0x1CE, 0x04);
outw(0x1CF, 0x41);
uint32_t * text_vid_mem = (uint32_t *)0xA0000;
text_vid_mem[0] = 0xA5ADFACE;
for (uintptr_t fb_offset = 0xE0000000; fb_offset < 0xFF000000; fb_offset += 0x01000000) {
/* Enable the higher memory */
for (uintptr_t i = fb_offset; i < fb_offset; i += 0x1000) {
// todo ident map fb
}
/* Go find it */
for (uintptr_t x = fb_offset; x < fb_offset + 0xFF0000; x += 0x1000) {
if (((uintptr_t *)x)[0] == 0xA5ADFACE) {
fb_buffer = (uint8_t *) x;
goto mem_found;
}
}
}
mem_found:
fb_res_x = res_x;
fb_res_y = res_y;
fb_res_b = PREFERRED_B;
return 0;
}

0
src/arch/amd64/fb.h Normal file
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@ -57,7 +57,8 @@ static int get_maxphysaddr() {
__cpuid(0x80000008, eax, ebx, ecx, edx);
return eax & 0xFF;
}
#define PREFERRED_VY 4096
#define PREFERRED_B 32
// entry point for amd64
void* amd64_shim(void *boot_info) {
struct pml4e *pml4 = (struct pml4e *)0x1000;

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@ -1,9 +1,12 @@
#include <lib.h>
#include <serial.h>
#include <fb.h>
void kmain(void *info) {
char buf[20];
*(char*)0xB8000 = 'c';
*(char*)(0xB8002 + 0x20'0000) = 'd';
itoa((long)info, buf, 10);
fb_init(1024, 768);
serial_out_str(buf);
}