diff options
Diffstat (limited to 'kernel/src/mem/paging.c')
| -rw-r--r-- | kernel/src/mem/paging.c | 55 |
1 files changed, 25 insertions, 30 deletions
diff --git a/kernel/src/mem/paging.c b/kernel/src/mem/paging.c index 19a2c3a..f714f66 100644 --- a/kernel/src/mem/paging.c +++ b/kernel/src/mem/paging.c @@ -1,17 +1,15 @@ #include <types.h> #include <paging.h> +#include <heap.h> #include <libk/stdio.h> -#include <debug.h> +#include <kernel_vma.h> void load_pt_lvl4(uint64_t*); __attribute__((aligned(4096))) uint64_t page_table_lvl4[512]; __attribute__((aligned(4096))) uint64_t page_table_lvl3[512]; -__attribute__((aligned(4096))) uint64_t page_table_lvl2_0[512]; -__attribute__((aligned(4096))) uint64_t page_table_lvl2_1[512]; -__attribute__((aligned(4096))) uint64_t page_table_lvl2_2[512]; -__attribute__((aligned(4096))) uint64_t page_table_lvl2_3[512]; +__attribute__((aligned(4096))) uint64_t page_table_lvl2[512]; void map_addr(uint64_t virt, uint64_t phys, uint32_t flags) { @@ -24,38 +22,35 @@ void map_addr(uint64_t virt, uint64_t phys, uint32_t flags) size_t pt_lvl2_i = (virt >> 21) % 0x200; // 2mb entry // size_t pt_lvl1_i = (virt >> 12) % 0x200; // 4kb entry - // first 4gb - if (pt_lvl4_i == 0) { - switch(pt_lvl3_i) { - case 0: - page_table_lvl2_0[pt_lvl2_i] = phys | flags; - break; - case 1: - page_table_lvl2_1[pt_lvl2_i] = phys | flags; - break; - case 2: - page_table_lvl2_2[pt_lvl2_i] = phys | flags; - break; - case 3: - page_table_lvl2_3[pt_lvl2_i] = phys | flags; - break; - } + uint64_t* pt_lvl3 = (uint64_t*)(page_table_lvl4[pt_lvl4_i] + KERNEL_VMA); + if (!((uint64_t)pt_lvl3 & FLAG_PRESENT)) { + pt_lvl3 = (uint64_t*)kalloc(4096); + page_table_lvl4[pt_lvl4_i] = ((uint64_t)pt_lvl3 - KERNEL_VMA) | flags; + } else { + pt_lvl3 = (uint64_t*)((uint64_t)pt_lvl3 - (uint64_t)pt_lvl3 % 4096); } + + uint64_t* pt_lvl2 = (uint64_t*)(pt_lvl3[pt_lvl3_i] + KERNEL_VMA); + if (!((uint64_t)pt_lvl2 & FLAG_PRESENT)) { + pt_lvl2 = (uint64_t*)kalloc(4096); + pt_lvl3[pt_lvl3_i] = ((uint64_t)pt_lvl2 - KERNEL_VMA) | flags; + } else { + pt_lvl2 -= (uint64_t)pt_lvl2 % 4096; + } + + pt_lvl2[pt_lvl2_i] = virt | flags; } void init_paging(void) { - page_table_lvl4[0] = (uint64_t)page_table_lvl3 + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER - KERNEL_VMA; - page_table_lvl3[0] = (uint64_t)page_table_lvl2_0 + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER - KERNEL_VMA; - page_table_lvl3[1] = (uint64_t)page_table_lvl2_1 + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER - KERNEL_VMA; - page_table_lvl3[2] = (uint64_t)page_table_lvl2_2 + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER - KERNEL_VMA; - page_table_lvl3[3] = (uint64_t)page_table_lvl2_3 + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER - KERNEL_VMA; - - // higher half map first 6mb - for (size_t i = 0; i < 3; i++) { - map_addr(KERNEL_VMA + PAGE_SIZE * i, 0x00000000 + PAGE_SIZE * i, FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER + FLAG_HUGE); + page_table_lvl4[511] = (uint64_t)page_table_lvl3 + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER - KERNEL_VMA; + page_table_lvl3[510] = (uint64_t)page_table_lvl2 + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER - KERNEL_VMA; + // 16mb kernel + 32mb heap + for (size_t i = 0; i < 24; i++) { + page_table_lvl2[i] = (uint64_t)0x0 + PAGE_SIZE * i + FLAG_PRESENT + FLAG_WRITABLE + FLAG_USER + FLAG_HUGE; } + load_pt_lvl4(page_table_lvl4); } |