diff options
| -rw-r--r-- | loader/loader_efi.c | 63 |
1 files changed, 35 insertions, 28 deletions
diff --git a/loader/loader_efi.c b/loader/loader_efi.c index a1d555a..1df9f68 100644 --- a/loader/loader_efi.c +++ b/loader/loader_efi.c @@ -37,10 +37,10 @@ enum page_type DATA_PAGE_TYPE = 0x3 }; -static uint64_t new_page_table(void) +static uint64_t *new_page_table(void) { EFI_STATUS status; - uint64_t table_address; + EFI_PHYSICAL_ADDRESS table_address; status = e_bs->AllocatePages(AllocateAnyPages, SystemMemoryType, @@ -55,9 +55,12 @@ static uint64_t new_page_table(void) e_bs->SetMem((void *)table_address, EFI_PAGE_SIZE, 0); - return table_address; + return (uint64_t *)table_address; } +#define PAGE_PRESENT 1 +#define PAGE_WRITE 2 + #define PAGE_MAP_LEVELS 4 #define PAGE_MAP_BITS 9 #define PAGE_OFFSET_BITS 12 @@ -68,24 +71,34 @@ static uint64_t new_page_table(void) #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_page_map(void) +{ + uint64_t map; + __asm__("mov %%cr3, %0" : "=r"(map)); + return (uint64_t *)(map & PAGE_TABLE_ADDRESS_MASK); +} -static uint64_t *get_pte(uint64_t *map, uint64_t virt) +void set_page_map(uint64_t *map) { - uint64_t next_map; + __asm__("mov %0, %%cr3" :: "r"(map)); +} +static uint64_t *get_page_entry(uint64_t *map, uint64_t virt) +{ for (int level = PAGE_MAP_LEVELS; level > 1; level--) { if (!map[page_table_index(virt, level)]) { - next_map = new_page_table(); - map[page_table_index(virt, level)] = next_map | 3; - map = (uint64_t *)next_map; + uint64_t *next_map = new_page_table(); + map[page_table_index(virt, level)] = + (uint64_t)next_map|PAGE_PRESENT|PAGE_WRITE; + map = next_map; } else { - next_map = map[page_table_index(virt, level)]; - next_map &= PAGE_TABLE_ADDRESS_MASK; - map = (uint64_t *)next_map; + uint64_t next_map_entry = map[page_table_index(virt, level)]; + next_map_entry &= PAGE_TABLE_ADDRESS_MASK; + map = (uint64_t *)next_map_entry; } } @@ -97,7 +110,7 @@ static void map_page(void *map, uint64_t phys, enum page_type type) { - *get_pte(map, virt) = phys | type; + *get_page_entry(map, virt) = phys | type; } enum page_type get_page_type(Elf64_Phdr *phdr) @@ -213,29 +226,23 @@ static void enter_kernel(struct system_image *kernel_image) efi_exit(status); } - uint64_t *efi_maps; - uint64_t efi_maps_raw; - - __asm__ ("mov %%cr3, %0" : "=r"(efi_maps_raw)); - efi_maps_raw &= PAGE_TABLE_ADDRESS_MASK; - efi_maps = (uint64_t *)efi_maps_raw; + uint64_t *efi_map = get_page_map(); + kernel_image->maps[0] = efi_map[0]; - ((uint64_t *)kernel_image->maps)[0] = efi_maps[0]; + set_page_map(kernel_image->maps); - __asm__ ( - "cli\n\t" - "mov %0, %%cr3\n\t" - "mov %1, %%rsp" - :: "r"(kernel_image->maps), - "r"((uint64_t)KERNEL_ENTRY_STACK_HEAD) - ); + __asm__ + ( + "mov %0, %%rsp" + : + : "r"((uint64_t)KERNEL_ENTRY_STACK_HEAD) + ); kernel_entry(&data); } void loader_main(void) { - struct system_image *kernel_image = open_system_image(kernel_path); Print(L"loading %s\r\n", kernel_path); @@ -252,7 +259,7 @@ void loader_main(void) efi_exit(EFI_ABORTED); } - kernel_image->maps = (void *)new_page_table(); + kernel_image->maps = 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"); |