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wip: kernel and virt allocator

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This commit is contained in:
0x35c
2025-11-13 12:09:36 +01:00
parent d30e1e4582
commit c5f8599d90
6 changed files with 34 additions and 35 deletions
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31
headers/memory.h
View File

@ -6,20 +6,21 @@
#include <stddef.h>
#include <stdint.h>
#define PRESENT (1 << 0)
#define RW (1 << 1)
#define SUPERVISOR (0 << 2)
#define ACCESSED (1 << 4)
#define INIT_FLAGS (PRESENT | RW | SUPERVISOR)
#define PAGE_SIZE 4096
#define PT_SIZE 1024
#define PD_SIZE 1024
#define PAGE_MASK 0xFFFFF000
#define HEAP_END 0xC0000000
#define HEAP_START ((uint32_t)&_kernel_end - HEAP_END)
#define KERNEL_START ((uint32_t)&_kernel_start)
#define KERNEL_END ((uint32_t)&_kernel_end - HEAP_END)
#define PT_START 256
#define PRESENT (1 << 0)
#define RW (1 << 1)
#define SUPERVISOR (0 << 2)
#define ACCESSED (1 << 4)
#define INIT_FLAGS (PRESENT | RW | SUPERVISOR)
#define PAGE_SIZE 4096
#define PT_SIZE 1024
#define PD_SIZE 1024
#define PAGE_MASK 0xFFFFF000
#define HEAP_END 0xC0000000
#define HEAP_START ((uint32_t)&_kernel_end - HEAP_END)
#define KERNEL_START ((uint32_t)&_kernel_start)
#define KERNEL_END ((uint32_t)&_kernel_end - HEAP_END)
#define KERNEL_PT_END 1020
#define KERNEL_PT_START 769
#define GET_PAGE_ADDR(pd_index, pt_index) \
((((uint32_t)pd_index * 1024) + (uint32_t)pt_index) * 4096)
@ -64,5 +65,5 @@ void *valloc_pages(size_t size, void **phys_addr);
int kfree_pages(void *page_ptr, size_t size);
int vfree_pages(void *page_ptr, size_t size);
void init_page_table(uint32_t page_table[1024], uint16_t start);
int16_t add_page_table(uint16_t pd_index);
int16_t add_page_table(uint16_t pd_index, uint16_t pt_start);
void switch_pd(uint32_t *pd, uint32_t *cr3);

12
src/memory/kern/page.c
View File

@ -13,12 +13,14 @@ static int16_t find_next_block(size_t nb_pages, uint16_t *pd_index_ptr,
uint32_t **page_table_ptr)
{
for (*pd_index_ptr = 769; *pd_index_ptr < 1021; (*pd_index_ptr)++) {
for (*pd_index_ptr = KERNEL_PT_START; *pd_index_ptr < KERNEL_PT_END;
(*pd_index_ptr)++) {
if (current_pd[(*pd_index_ptr)] == 0x02) {
if (add_page_table(*pd_index_ptr) < 0)
if (add_page_table(*pd_index_ptr, KERNEL_PT_START) < 0)
return -2;
}
*page_table_ptr = (uint32_t *)GET_PAGE_ADDR(769, *pd_index_ptr);
*page_table_ptr =
(uint32_t *)GET_PAGE_ADDR(KERNEL_PT_START, *pd_index_ptr);
for (uint16_t i = 0; i + nb_pages - 1 < PT_SIZE; i++) {
uint16_t j;
for (j = 0; (*page_table_ptr)[i + j] >> 12 == i + j &&
@ -67,7 +69,7 @@ int kfree_pages(void *page_ptr, size_t size)
const uint32_t pd_index = page_index / PD_SIZE;
const uint32_t pt_index = page_index % PD_SIZE;
if ((uint32_t)pd_index > 0x300) {
if ((uint32_t)pd_index < KERNEL_PT_START || pd_index > KERNEL_PT_END) {
kprintf(KERN_WARNING "Address out of range\n");
return -1;
} else if (page_addr % PAGE_SIZE) {
@ -78,7 +80,7 @@ int kfree_pages(void *page_ptr, size_t size)
return -1;
}
uint32_t *page_table =
(uint32_t *)GET_PAGE_ADDR(0, PT_START + pd_index);
(uint32_t *)GET_PAGE_ADDR(KERNEL_PT_START, pd_index);
for (uint16_t i = pt_index; i < pt_index + nb_pages; i++) {
if (page_table[i] >> 12 == i) {
kprintf(KERN_WARNING "Page already free\n");

4
src/memory/memory.c
View File

@ -113,10 +113,10 @@ static void init_frame_zones(void)
void init_memory(multiboot_info_t *mbd, uint32_t magic)
{
for (uint16_t i = 769; i < 1021; i++)
for (uint16_t i = KERNEL_PT_START; i < 1020; i++)
kernel_pd[i] = 0x02;
init_page_table(page_table_default, 0);
kernel_pd[0] = ((uint32_t)page_table_default - HEAP_END) | 0x03;
kernel_pd[1020] = ((uint32_t)page_table_default - HEAP_END) | 0x03;
current_pd = kernel_pd;
init_multiboot(mbd, magic);
init_frame_zones();

8
src/memory/page_table.c
View File

@ -6,15 +6,13 @@ void init_page_table(uint32_t page_table[1024], uint16_t start)
page_table[i] = (i << 12) | 0x03;
}
int16_t add_page_table(uint16_t pd_index)
int16_t add_page_table(uint16_t pd_index, uint16_t pt_start)
{
void *frame = alloc_frame();
if (!frame)
return -1;
page_table_default[PT_START + pd_index] =
((uint32_t)frame & PAGE_MASK) | 0x03;
uint32_t *page_table =
(uint32_t *)GET_PAGE_ADDR(0, PT_START + pd_index);
page_table_default[pd_index] = ((uint32_t)frame & PAGE_MASK) | 0x03;
uint32_t *page_table = (uint32_t *)GET_PAGE_ADDR(pt_start, pd_index);
init_page_table(page_table, 0);
kernel_pd[pd_index] = ((uint32_t)frame & PAGE_MASK) | 0x03;
return 0;

12
src/memory/virt/page.c
View File

@ -12,13 +12,12 @@
static int16_t find_next_block(size_t nb_pages, uint16_t *pd_index_ptr,
uint32_t **page_table_ptr)
{
for (*pd_index_ptr = 1; *pd_index_ptr < 768; (*pd_index_ptr)++) {
for (*pd_index_ptr = 2; *pd_index_ptr < 768; (*pd_index_ptr)++) {
if (current_pd[(*pd_index_ptr)] == 0x02) {
if (add_page_table(*pd_index_ptr) < 0)
if (add_page_table(*pd_index_ptr, 1) < 0)
return -2;
}
*page_table_ptr =
(uint32_t *)GET_PAGE_ADDR(0, *pd_index_ptr + PT_START);
*page_table_ptr = (uint32_t *)GET_PAGE_ADDR(1, *pd_index_ptr);
for (uint16_t i = 0; i + nb_pages - 1 < PT_SIZE; i++) {
uint16_t j;
for (j = 0; (*page_table_ptr)[i + j] >> 12 == i + j &&
@ -77,11 +76,10 @@ int vfree_pages(void *page_ptr, size_t size)
kprintf(KERN_WARNING "Invalid number of frames\n");
return -1;
}
uint32_t *page_table =
(uint32_t *)GET_PAGE_ADDR(0, PT_START + pd_index);
uint32_t *page_table = (uint32_t *)GET_PAGE_ADDR(1, pd_index);
for (uint16_t i = pt_index; i < pt_index + nb_pages; i++) {
if (page_table[i] >> 12 == i) {
kprintf(KERN_WARNING "Page already free\n");
kprintf(KERN_WARNING "Page already freed\n");
return -2;
}
free_frame((void *)(page_table[i] & PAGE_MASK));

2
src/multitasking/thread.c
View File

@ -15,7 +15,7 @@ struct tcb *create_thread(struct pcb *process, void (*entry)(void))
return NULL;
new_tcb->tid = process->tid++;
new_tcb->esp0 = kalloc_pages(STACK_SIZE, NULL);
new_tcb->esp0 = valloc_pages(STACK_SIZE, NULL);
if (!new_tcb->esp0) {
vfree(new_tcb);
return NULL;