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#include <stdint.h>
#include <kernel/memory/paging.h>
#include <kernel/memory/alloc.h>
#include <kernel/system.h>
#include <kernel/lib/lib.h>
#include <kernel/io/io.h>
#include <kernel/acpi/acpi.h>
#include <kernel/tasks/process.h>
#include <kernel/interrupts/interrupts.h>
struct page_directory *paging_current_directory = NULL;
struct page_directory *paging_root_directory = NULL;
/* void paging_install(uint32_t multiboot_address) */
/* { */
/* if (!memory_init(multiboot_address)) */
/* paging_set_present(0, memory_get_all() >> 3); // /4 */
/* paging_set_used(0, ((uint32_t)ASM_KERNEL_END >> 12) + 1); // /4096 */
/* } */
struct page_table *get_cr3()
{
uint32_t cr3;
asm volatile("movl %%cr3, %%eax" : "=a"(cr3));
return (struct page_table *)cr3;
}
uint32_t get_cr0()
{
uint32_t cr0;
asm volatile("movl %%cr0, %%eax" : "=a"(cr0));
return cr0;
}
void set_cr3(struct page_directory *dir)
{
uint32_t addr = (uint32_t)&dir->tables[0];
asm volatile("movl %%eax, %%cr3" ::"a"(addr));
}
void set_cr0(uint32_t cr0)
{
asm volatile("movl %%eax, %%cr0" ::"a"(cr0));
}
void paging_disable()
{
set_cr0(get_cr0() | 0x7fffffff);
}
void paging_enable()
{
set_cr3(paging_current_directory);
set_cr0(get_cr0() | 0x80000000);
}
void paging_switch_directory(struct page_directory *dir)
{
set_cr3(dir);
set_cr0(get_cr0() | 0x80000000);
}
struct page_directory *paging_make_directory()
{
struct page_directory *dir =
(struct page_directory *)kmalloc_a(sizeof(struct page_directory));
for (int i = 0; i < 1024; i++)
dir->tables[i] = EMPTY_TAB;
return dir;
}
struct page_table *paging_make_table()
{
struct page_table *tab = (struct page_table *)kmalloc_a(sizeof(struct page_table));
for (int i = 0; i < 1024; i++) {
tab->pages[i].present = 0;
tab->pages[i].rw = 1;
}
return tab;
}
void paging_map(struct page_directory *dir, uint32_t phys, uint32_t virt)
{
short id = virt >> 22;
struct page_table *tab = paging_make_table();
dir->tables[id] = ((struct page_table *)((uint32_t)tab | 3)); // RW
for (int i = 0; i < 1024; i++) {
tab->pages[i].frame = phys >> 12;
tab->pages[i].present = 1;
phys += 4096;
}
}
void paging_map_user(struct page_directory *dir, uint32_t phys, uint32_t virt)
{
short id = virt >> 22;
struct page_table *tab = paging_make_table();
dir->tables[id] = ((struct page_table *)((uint32_t)tab | 3 | 4)); // RW + usermode
int i;
for (i = 0; i < 1024; i++) {
tab->pages[i].frame = phys >> 12;
tab->pages[i].present = 1;
tab->pages[i].user = 1;
phys += 4096;
}
}
void paging_install()
{
kheap_init();
paging_current_directory = paging_make_directory();
paging_root_directory = paging_current_directory;
for (uint32_t i = 0; i < 0xF0000000; i += PAGE_S)
paging_map(paging_root_directory, i, i);
paging_switch_directory(paging_root_directory);
info("Installed paging");
// Test mallocing
uintptr_t a = (uintptr_t)kmalloc(4096); // TODO: Fix "can't collapse top of heap"
uintptr_t b = (uintptr_t)kmalloc(4096);
kfree((void *)b);
kfree((void *)a);
uintptr_t c = (uintptr_t)kmalloc(2048);
assert(a == c);
info("kmalloc test succeeded!");
}
void paging_convert_page(struct page_directory *kdir)
{
for (int i = 0; i < 1024; i++) {
kdir->tables[i] = (struct page_table *)((uint32_t)kdir->tables[i] | 4); // Usermode
if (((uint32_t)kdir->tables[i]) & 1) { // Is present
for (int j = 0; j < 1024; j++)
kdir->tables[i]->pages[j].user = 1; // Usermode
}
}
}
struct page_directory *paging_copy_user_directory(struct page_directory *dir)
{
struct page_directory *copy = paging_make_directory();
memcpy(copy, paging_root_directory, sizeof(struct page_directory));
for (uint32_t i = 0; i < 1024; i++) {
if (((uint32_t)dir->tables[i]) & 4) {
struct page_table *tab =
(struct page_table *)((uint32_t)dir->tables[i] & 0xFFFFF000);
void *buffer = kmalloc_a(PAGE_S);
memcpy(buffer, (void *)(tab->pages[0].frame << 12), PAGE_S);
paging_map_user(copy, (uint32_t)buffer, (uint32_t)i << 22);
}
}
return copy;
}
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