diff options
| -rw-r--r-- | loader/loader_efi.c | 56 |
1 files changed, 30 insertions, 26 deletions
diff --git a/loader/loader_efi.c b/loader/loader_efi.c index e531521..f2f7cde 100644 --- a/loader/loader_efi.c +++ b/loader/loader_efi.c @@ -37,15 +37,6 @@ enum page_type DATA_PAGE_TYPE = 0x3 }; -#define PAGE_MAP_LEVELS 4 -#define PAGE_MAP_BITS 9 -#define PAGE_OFFSET_BITS 12 - -#define PAGE_TABLE_INDEX_MASK ((1 << PAGE_MAP_BITS) - 1) -#define PAGE_TABLE_ADDRESS_MASK ~((1 << PAGE_OFFSET_BITS) - 1) - -#define page_table_index(v, l) ((v >> ((PAGE_OFFSET_BITS + (l - 1) * PAGE_MAP_BITS))) & PAGE_TABLE_INDEX_MASK) - static uint64_t new_page_table(void) { EFI_STATUS status; @@ -67,31 +58,46 @@ static uint64_t new_page_table(void) return table_address; } -static void map_page(void *map, - uint64_t virt, - uint64_t phys, - enum page_type type) +#define PAGE_MAP_LEVELS 4 +#define PAGE_MAP_BITS 9 +#define PAGE_OFFSET_BITS 12 + +#define PAGE_TABLE_INDEX_MASK ((1 << PAGE_MAP_BITS) - 1) +#define PAGE_TABLE_ADDRESS_MASK ~((1 << PAGE_OFFSET_BITS) - 1) + +#define page_table_index_bits(l) (PAGE_OFFSET_BITS + PAGE_MAP_BITS * (l - 1)) +#define page_table_index(v, l) ((v >> page_table_index_bits(l)) & PAGE_TABLE_INDEX_MASK) + + +static uint64_t *get_pte(uint64_t *map, uint64_t virt) { - uint64_t *this_map = (uint64_t *)map; uint64_t next_map; - for (int level = 4; level > 1; level--) + for (int level = PAGE_MAP_LEVELS; level > 1; level--) { - if (!this_map[page_table_index(virt, level)]) + if (!map[page_table_index(virt, level)]) { next_map = new_page_table(); - this_map[page_table_index(virt, level)] = next_map | 3; - this_map = (uint64_t *)next_map; + map[page_table_index(virt, level)] = next_map | 3; + map = (uint64_t *)next_map; } else { - next_map = this_map[page_table_index(virt, level)]; + next_map = map[page_table_index(virt, level)]; next_map &= PAGE_TABLE_ADDRESS_MASK; - this_map = (uint64_t *)next_map; + map = (uint64_t *)next_map; } } - this_map[page_table_index(virt, 1)] = phys | type; + return &map[page_table_index(virt, 1)]; +} + +static void map_page(void *map, + uint64_t virt, + uint64_t phys, + enum page_type type) +{ + *get_pte(map, virt) = phys | type; } enum page_type get_page_type(Elf64_Phdr *phdr) @@ -117,6 +123,7 @@ static void map_pages(void *map, { for (size_t offset = 0; offset < size; offset += EFI_PAGE_SIZE) { + Print(L"mapping page %16.0lx to %16.0lx\r\n", virt + offset, phys + offset); map_page(map, virt + offset, phys + offset, type); } } @@ -128,11 +135,7 @@ static void create_kernel_maps(struct system_image *image) for (int i = 0; i < ehdr->e_phnum; i++) { - if (phdrs[i].p_type != PT_LOAD) - { - continue; - } - else + if (phdrs[i].p_type == PT_LOAD) { uint64_t virt_begin = phdrs[i].p_vaddr; uint64_t phys_begin = image->buffer.base + phdrs[i].p_paddr; @@ -207,6 +210,7 @@ void loader_main(void) } kernel_image->maps = (void *)new_page_table(); + Print(L"kernel pml4 %16.0lx\r\n", kernel_image->maps); create_kernel_maps(kernel_image); Print(L"kernel maps created. entering kernel\r\n"); enter_kernel(kernel_image); |