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fix: gdt init no longer crashes

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WIP: change page directory and stuff so the memory can work properly
This commit is contained in:
0x35c 2024-10-14 23:36:41 +02:00
parent 5969dcca54
commit 9855669662
3 changed files with 12 additions and 18 deletions
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2
headers/gdt.h
View File

@ -2,7 +2,7 @@
#include <stdint.h> #include <stdint.h>
#define GDT_ADDRESS 0x00000800 #define GDT_ADDRESS 0xC0105040
#define GDT_SIZE 7 #define GDT_SIZE 7
// https://wiki.osdev.org/Global_Descriptor_Table#GDTR // https://wiki.osdev.org/Global_Descriptor_Table#GDTR

5
src/kernel.c
View File

@ -27,9 +27,10 @@ void kernel_main(void)
terminal_initialize(); terminal_initialize();
init_gdt(); init_gdt();
init_idt(); init_idt();
init_memory(); /* init_memory(); */
load_drivers(); load_drivers();
kprintf("I see no way to confuse an array of 256 seg:off pairs with a " kprintf(KERN_ALERT
"I see no way to confuse an array of 256 seg:off pairs with a "
"complex 8*unknown quantity -byte descriptor table. -- Troy " "complex 8*unknown quantity -byte descriptor table. -- Troy "
"Martin 03:50, 22 March 2009 (UTC)\n"); "Martin 03:50, 22 March 2009 (UTC)\n");
shell_init(); shell_init();

21
src/memory/frame.c
View File

@ -7,18 +7,10 @@
#include "utils.h" #include "utils.h"
#define MAX_FRAMES 1048319 #define MAX_FRAMES 1048319
#define GET_FRAME(i) (frame_table[i / 8] & (1 << (i % 8)))
#define SET_FRAME(i, used) \
do { \
if (used) \
frame_table[i / 8] |= (1 << (i % 8)); \
else \
frame_table[i / 8] &= ~(1 << (i % 8)); \
} while (0)
extern uint32_t end_kernel; static uint32_t end_kernel; // WIP but it's useless now
static uint8_t frame_table[CEIL(MAX_FRAMES, 8)]; static uint8_t frame_table[MAX_FRAMES];
static uint32_t remaining_frames = MAX_FRAMES; static uint32_t remaining_frames = MAX_FRAMES;
void *alloc_frames(size_t size) void *alloc_frames(size_t size)
@ -32,17 +24,18 @@ void *alloc_frames(size_t size)
size_t i = 0; size_t i = 0;
while (i < MAX_FRAMES) { while (i < MAX_FRAMES) {
size_t free_frames = 1; size_t free_frames = 1;
while (!GET_FRAME(i + free_frames) && free_frames < nb_frames && while (!frame_table[i + free_frames] && free_frames < nb_frames)
i + free_frames < remaining_frames)
free_frames++; free_frames++;
if (free_frames == nb_frames) if (free_frames == nb_frames)
goto end; goto end;
if (!free_frames)
i++;
i += free_frames; i += free_frames;
} }
end: end:
if (i != MAX_FRAMES) { if (i != MAX_FRAMES) {
for (size_t j = 0; j < nb_frames; j++) for (size_t j = 0; j < nb_frames; j++)
SET_FRAME(j + i, 1); frame_table[j + i] = 1;
remaining_frames -= nb_frames; remaining_frames -= nb_frames;
return &end_kernel + i * PAGE_SIZE; return &end_kernel + i * PAGE_SIZE;
} }
@ -66,7 +59,7 @@ int free_frames(void *frame_ptr, size_t size)
return -1; return -1;
} }
for (size_t i = start; i < start + nb_frames; i++) for (size_t i = start; i < start + nb_frames; i++)
SET_FRAME(i, 0); frame_table[i] = 0;
remaining_frames += nb_frames; remaining_frames += nb_frames;
return 0; return 0;
} }