#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined (UEFI) # include #endif #if defined (BIOS) __attribute__((noinline, section(".realmode"))) noreturn static void spinup(uint8_t drive, void *buf) { struct idtr real_mode_idt; real_mode_idt.limit = 0x3ff; real_mode_idt.ptr = 0; asm volatile ( "cli\n\t" "cld\n\t" // Safe stack location "mov $0x7c00, %%esp\n\t" // move buffer to final location "mov $0x7c00, %%edi\n\t" "mov $512, %%ecx\n\t" "rep movsb\n\t" "lidt (%%eax)\n\t" "pushl $0x08\n\t" "pushl $1f\n\t" "lret\n\t" "1: .code16\n\t" "movw $0x10, %%ax\n\t" "movw %%ax, %%ds\n\t" "movw %%ax, %%es\n\t" "movw %%ax, %%fs\n\t" "movw %%ax, %%gs\n\t" "movw %%ax, %%ss\n\t" "movl %%cr0, %%eax\n\t" "andb $0xfe, %%al\n\t" "movl %%eax, %%cr0\n\t" "movl $1f, %%eax\n\t" "pushw $0\n\t" "pushw %%ax\n\t" "lret\n\t" "1:\n\t" "xorw %%ax, %%ax\n\t" "movw %%ax, %%ds\n\t" "movw %%ax, %%es\n\t" "movw %%ax, %%fs\n\t" "movw %%ax, %%gs\n\t" "movw %%ax, %%ss\n\t" "sti\n\t" "pushw $0\n\t" "pushw $0x7c00\n\t" "lret\n\t" ".code32\n\t" : : "a" (&real_mode_idt), "d" (drive), "S"(buf) : "memory" ); __builtin_unreachable(); } noreturn void chainload(char *config, char *cmdline) { (void)cmdline; uint64_t val; int part; { char *part_config = config_get_value(config, 0, "PARTITION"); if (part_config == NULL) { part = 0; } else { val = strtoui(part_config, NULL, 10); if (val > 256) { panic(true, "chainload: BIOS partition number outside range 0-256"); } part = val; } } int drive; { char *drive_config = config_get_value(config, 0, "DRIVE"); if (drive_config == NULL) { drive = boot_volume->index; } else { val = strtoui(drive_config, NULL, 10); if (val < 1 || val > 256) { panic(true, "chainload: BIOS drive number outside range 1-256"); } drive = val; } } struct volume *p = volume_get_by_coord(false, drive, part); char *gpt_guid_s = config_get_value(config, 0, "GPT_GUID"); if (gpt_guid_s == NULL) { gpt_guid_s = config_get_value(config, 0, "GPT_UUID"); } if (gpt_guid_s != NULL) { struct guid guid; if (!string_to_guid_be(&guid, gpt_guid_s)) { panic(true, "chainload: Malformed GUID"); } p = volume_get_by_guid(&guid); if (p == NULL) { if (!string_to_guid_mixed(&guid, gpt_guid_s)) { panic(true, "chainload: Malformed GUID"); } p = volume_get_by_guid(&guid); } if (p == NULL) { panic(true, "chainload: No matching GPT drive for GPT_GUID found"); } if (p->partition != 0) { panic(true, "chainload: GPT_GUID is that of a partition, not a drive"); } p = volume_get_by_coord(false, p->index, part); if (p == NULL) { panic(true, "chainload: Partition specified is not valid"); } goto load; } char *mbr_id_s = config_get_value(config, 0, "MBR_ID"); if (mbr_id_s != NULL) { uint32_t mbr_id = strtoui(mbr_id_s, NULL, 16); for (size_t i = 0; i < volume_index_i; i++) { p = volume_index[i]; if (!is_valid_mbr(p)) { continue; } uint32_t mbr_id_1; volume_read(p, &mbr_id_1, 0x1b8, sizeof(uint32_t)); if (mbr_id_1 == mbr_id) { p = volume_get_by_coord(false, p->index, part); if (p == NULL) { panic(true, "chainload: Partition specified is not valid"); } goto load; } } panic(true, "chainload: No matching MBR ID found"); } load: bios_chainload_volume(p); panic(true, "chainload: Volume is not bootable"); } void bios_chainload_volume(struct volume *p) { vga_textmode_init(false); void *buf = ext_mem_alloc(512); volume_read(p, buf, 0, 512); uint16_t *boot_sig = (uint16_t *)(buf + 0x1fe); if (*boot_sig != 0xaa55) { return; } spinup(p->drive, buf); } #elif defined (UEFI) noreturn void chainload(char *config, char *cmdline) { char *image_path = config_get_value(config, 0, "IMAGE_PATH"); if (image_path == NULL) panic(true, "chainload: IMAGE_PATH not specified"); struct file_handle *image; if ((image = uri_open(image_path)) == NULL) panic(true, "chainload: Failed to open image with path `%s`. Is the path correct?", image_path); efi_chainload_file(config, cmdline, image); } noreturn void efi_chainload_file(char *config, char *cmdline, struct file_handle *image) { EFI_STATUS status; EFI_HANDLE efi_part_handle = image->efi_part_handle; void *_ptr = freadall(image, MEMMAP_RESERVED); size_t image_size = image->size; void *ptr; status = gBS->AllocatePool(EfiLoaderData, image_size, &ptr); if (status) panic(true, "chainload: Allocation failure"); memcpy(ptr, _ptr, image_size); pmm_free(_ptr, image->size); fclose(image); term_notready(); size_t req_width = 0, req_height = 0, req_bpp = 0; char *resolution = config_get_value(config, 0, "RESOLUTION"); if (resolution != NULL) parse_resolution(&req_width, &req_height, &req_bpp, resolution); struct fb_info *fbinfo; size_t fb_count; fb_init(&fbinfo, &fb_count, req_width, req_height, req_bpp); size_t cmdline_len = strlen(cmdline); CHAR16 *new_cmdline; status = gBS->AllocatePool(EfiLoaderData, cmdline_len * sizeof(CHAR16), (void **)&new_cmdline); if (status) { panic(true, "chainload: Allocation failure"); } for (size_t i = 0; i < cmdline_len + 1; i++) { new_cmdline[i] = cmdline[i]; } pmm_release_uefi_mem(); MEMMAP_DEVICE_PATH memdev_path[2]; memdev_path[0].Header.Type = HARDWARE_DEVICE_PATH; memdev_path[0].Header.SubType = HW_MEMMAP_DP; memdev_path[0].Header.Length[0] = sizeof(MEMMAP_DEVICE_PATH); memdev_path[0].Header.Length[1] = sizeof(MEMMAP_DEVICE_PATH) >> 8; memdev_path[0].MemoryType = EfiLoaderData; memdev_path[0].StartingAddress = (uintptr_t)ptr; memdev_path[0].EndingAddress = (uintptr_t)ptr + image_size; memdev_path[1].Header.Type = END_DEVICE_PATH_TYPE; memdev_path[1].Header.SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE; memdev_path[1].Header.Length[0] = sizeof(EFI_DEVICE_PATH); memdev_path[1].Header.Length[1] = sizeof(EFI_DEVICE_PATH) >> 8; EFI_HANDLE new_handle = 0; status = gBS->LoadImage(0, efi_image_handle, (EFI_DEVICE_PATH *)memdev_path, ptr, image_size, &new_handle); if (status) { panic(false, "chainload: LoadImage failure (%x)", status); } // Apparently we need to make sure that the DeviceHandle field is the same // as us (the loader) for some EFI images to properly work (Windows for instance) EFI_GUID loaded_img_prot_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID; EFI_LOADED_IMAGE_PROTOCOL *new_handle_loaded_image = NULL; status = gBS->HandleProtocol(new_handle, &loaded_img_prot_guid, (void **)&new_handle_loaded_image); if (status) { panic(false, "chainload: HandleProtocol failure (%x)", status); } if (efi_part_handle != 0) { new_handle_loaded_image->DeviceHandle = efi_part_handle; } new_handle_loaded_image->LoadOptionsSize = cmdline_len * sizeof(CHAR16); new_handle_loaded_image->LoadOptions = new_cmdline; UINTN exit_data_size = 0; CHAR16 *exit_data = NULL; EFI_STATUS exit_status = gBS->StartImage(new_handle, &exit_data_size, &exit_data); status = gBS->Exit(efi_image_handle, exit_status, exit_data_size, exit_data); if (status) { panic(false, "chainload: Exit failure (%x)", status); } __builtin_unreachable(); } #endif