// SPDX-License-Identifier: GPL-2.0-only /* ----------------------------------------------------------------------- * * Copyright 2011 Intel Corporation; author Matt Fleming * * ----------------------------------------------------------------------- */ #include #include #include #include #include #include #include #include #include "efistub.h" /* Maximum physical address for 64-bit kernel with 4-level paging */ #define MAXMEM_X86_64_4LEVEL (1ull << 46) const efi_system_table_t *efi_system_table; extern u32 image_offset; static efi_loaded_image_t *image = NULL; static efi_status_t preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) { struct pci_setup_rom *rom = NULL; efi_status_t status; unsigned long size; uint64_t romsize; void *romimage; /* * Some firmware images contain EFI function pointers at the place where * the romimage and romsize fields are supposed to be. Typically the EFI * code is mapped at high addresses, translating to an unrealistically * large romsize. The UEFI spec limits the size of option ROMs to 16 * MiB so we reject any ROMs over 16 MiB in size to catch this. */ romimage = efi_table_attr(pci, romimage); romsize = efi_table_attr(pci, romsize); if (!romimage || !romsize || romsize > SZ_16M) return EFI_INVALID_PARAMETER; size = romsize + sizeof(*rom); status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&rom); if (status != EFI_SUCCESS) { efi_err("Failed to allocate memory for 'rom'\n"); return status; } memset(rom, 0, sizeof(*rom)); rom->data.type = SETUP_PCI; rom->data.len = size - sizeof(struct setup_data); rom->data.next = 0; rom->pcilen = pci->romsize; *__rom = rom; status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, PCI_VENDOR_ID, 1, &rom->vendor); if (status != EFI_SUCCESS) { efi_err("Failed to read rom->vendor\n"); goto free_struct; } status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, PCI_DEVICE_ID, 1, &rom->devid); if (status != EFI_SUCCESS) { efi_err("Failed to read rom->devid\n"); goto free_struct; } status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus, &rom->device, &rom->function); if (status != EFI_SUCCESS) goto free_struct; memcpy(rom->romdata, romimage, romsize); return status; free_struct: efi_bs_call(free_pool, rom); return status; } /* * There's no way to return an informative status from this function, * because any analysis (and printing of error messages) needs to be * done directly at the EFI function call-site. * * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we * just didn't find any PCI devices, but there's no way to tell outside * the context of the call. */ static void setup_efi_pci(struct boot_params *params) { efi_status_t status; void **pci_handle = NULL; efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID; unsigned long size = 0; struct setup_data *data; efi_handle_t h; int i; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &pci_proto, NULL, &size, pci_handle); if (status == EFI_BUFFER_TOO_SMALL) { status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&pci_handle); if (status != EFI_SUCCESS) { efi_err("Failed to allocate memory for 'pci_handle'\n"); return; } status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &pci_proto, NULL, &size, pci_handle); } if (status != EFI_SUCCESS) goto free_handle; data = (struct setup_data *)(unsigned long)params->hdr.setup_data; while (data && data->next) data = (struct setup_data *)(unsigned long)data->next; for_each_efi_handle(h, pci_handle, size, i) { efi_pci_io_protocol_t *pci = NULL; struct pci_setup_rom *rom; status = efi_bs_call(handle_protocol, h, &pci_proto, (void **)&pci); if (status != EFI_SUCCESS || !pci) continue; status = preserve_pci_rom_image(pci, &rom); if (status != EFI_SUCCESS) continue; if (data) data->next = (unsigned long)rom; else params->hdr.setup_data = (unsigned long)rom; data = (struct setup_data *)rom; } free_handle: efi_bs_call(free_pool, pci_handle); } static void retrieve_apple_device_properties(struct boot_params *boot_params) { efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID; struct setup_data *data, *new; efi_status_t status; u32 size = 0; apple_properties_protocol_t *p; status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p); if (status != EFI_SUCCESS) return; if (efi_table_attr(p, version) != 0x10000) { efi_err("Unsupported properties proto version\n"); return; } efi_call_proto(p, get_all, NULL, &size); if (!size) return; do { status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size + sizeof(struct setup_data), (void **)&new); if (status != EFI_SUCCESS) { efi_err("Failed to allocate memory for 'properties'\n"); return; } status = efi_call_proto(p, get_all, new->data, &size); if (status == EFI_BUFFER_TOO_SMALL) efi_bs_call(free_pool, new); } while (status == EFI_BUFFER_TOO_SMALL); new->type = SETUP_APPLE_PROPERTIES; new->len = size; new->next = 0; data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data; if (!data) { boot_params->hdr.setup_data = (unsigned long)new; } else { while (data->next) data = (struct setup_data *)(unsigned long)data->next; data->next = (unsigned long)new; } } static const efi_char16_t apple[] = L"Apple"; static void setup_quirks(struct boot_params *boot_params) { efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long) efi_table_attr(efi_system_table, fw_vendor); if (!memcmp(fw_vendor, apple, sizeof(apple))) { if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) retrieve_apple_device_properties(boot_params); } } /* * See if we have Universal Graphics Adapter (UGA) protocol */ static efi_status_t setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) { efi_status_t status; u32 width, height; void **uga_handle = NULL; efi_uga_draw_protocol_t *uga = NULL, *first_uga; efi_handle_t handle; int i; status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&uga_handle); if (status != EFI_SUCCESS) return status; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, uga_proto, NULL, &size, uga_handle); if (status != EFI_SUCCESS) goto free_handle; height = 0; width = 0; first_uga = NULL; for_each_efi_handle(handle, uga_handle, size, i) { efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; u32 w, h, depth, refresh; void *pciio; status = efi_bs_call(handle_protocol, handle, uga_proto, (void **)&uga); if (status != EFI_SUCCESS) continue; pciio = NULL; efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); if (status == EFI_SUCCESS && (!first_uga || pciio)) { width = w; height = h; /* * Once we've found a UGA supporting PCIIO, * don't bother looking any further. */ if (pciio) break; first_uga = uga; } } if (!width && !height) goto free_handle; /* EFI framebuffer */ si->orig_video_isVGA = VIDEO_TYPE_EFI; si->lfb_depth = 32; si->lfb_width = width; si->lfb_height = height; si->red_size = 8; si->red_pos = 16; si->green_size = 8; si->green_pos = 8; si->blue_size = 8; si->blue_pos = 0; si->rsvd_size = 8; si->rsvd_pos = 24; free_handle: efi_bs_call(free_pool, uga_handle); return status; } static void setup_graphics(struct boot_params *boot_params) { efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; struct screen_info *si; efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; efi_status_t status; unsigned long size; void **gop_handle = NULL; void **uga_handle = NULL; si = &boot_params->screen_info; memset(si, 0, sizeof(*si)); size = 0; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &graphics_proto, NULL, &size, gop_handle); if (status == EFI_BUFFER_TOO_SMALL) status = efi_setup_gop(si, &graphics_proto, size); if (status != EFI_SUCCESS) { size = 0; status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &uga_proto, NULL, &size, uga_handle); if (status == EFI_BUFFER_TOO_SMALL) setup_uga(si, &uga_proto, size); } } static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) { efi_bs_call(exit, handle, status, 0, NULL); for(;;) asm("hlt"); } void startup_32(struct boot_params *boot_params); void __noreturn efi_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg, struct boot_params *boot_params); /* * Because the x86 boot code expects to be passed a boot_params we * need to create one ourselves (usually the bootloader would create * one for us). */ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg) { struct boot_params *boot_params; struct setup_header *hdr; void *image_base; efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; int options_size = 0; efi_status_t status; char *cmdline_ptr; efi_system_table = sys_table_arg; /* Check if we were booted by the EFI firmware */ if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) efi_exit(handle, EFI_INVALID_PARAMETER); status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); if (status != EFI_SUCCESS) { efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); efi_exit(handle, status); } image_base = efi_table_attr(image, image_base); image_offset = (void *)startup_32 - image_base; status = efi_allocate_pages(sizeof(struct boot_params), (unsigned long *)&boot_params, ULONG_MAX); if (status != EFI_SUCCESS) { efi_err("Failed to allocate lowmem for boot params\n"); efi_exit(handle, status); } memset(boot_params, 0x0, sizeof(struct boot_params)); hdr = &boot_params->hdr; /* Copy the setup header from the second sector to boot_params */ memcpy(&hdr->jump, image_base + 512, sizeof(struct setup_header) - offsetof(struct setup_header, jump)); /* * Fill out some of the header fields ourselves because the * EFI firmware loader doesn't load the first sector. */ hdr->root_flags = 1; hdr->vid_mode = 0xffff; hdr->boot_flag = 0xAA55; hdr->type_of_loader = 0x21; /* Convert unicode cmdline to ascii */ cmdline_ptr = efi_convert_cmdline(image, &options_size); if (!cmdline_ptr) goto fail; efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); hdr->ramdisk_image = 0; hdr->ramdisk_size = 0; /* * Disregard any setup data that was provided by the bootloader: * setup_data could be pointing anywhere, and we have no way of * authenticating or validating the payload. */ hdr->setup_data = 0; efi_stub_entry(handle, sys_table_arg, boot_params); /* not reached */ fail: efi_free(sizeof(struct boot_params), (unsigned long)boot_params); efi_exit(handle, status); } static void add_e820ext(struct boot_params *params, struct setup_data *e820ext, u32 nr_entries) { struct setup_data *data; e820ext->type = SETUP_E820_EXT; e820ext->len = nr_entries * sizeof(struct boot_e820_entry); e820ext->next = 0; data = (struct setup_data *)(unsigned long)params->hdr.setup_data; while (data && data->next) data = (struct setup_data *)(unsigned long)data->next; if (data) data->next = (unsigned long)e820ext; else params->hdr.setup_data = (unsigned long)e820ext; } static efi_status_t setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) { struct boot_e820_entry *entry = params->e820_table; struct efi_info *efi = ¶ms->efi_info; struct boot_e820_entry *prev = NULL; u32 nr_entries; u32 nr_desc; int i; nr_entries = 0; nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; for (i = 0; i < nr_desc; i++) { efi_memory_desc_t *d; unsigned int e820_type = 0; unsigned long m = efi->efi_memmap; #ifdef CONFIG_X86_64 m |= (u64)efi->efi_memmap_hi << 32; #endif d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); switch (d->type) { case EFI_RESERVED_TYPE: case EFI_RUNTIME_SERVICES_CODE: case EFI_RUNTIME_SERVICES_DATA: case EFI_MEMORY_MAPPED_IO: case EFI_MEMORY_MAPPED_IO_PORT_SPACE: case EFI_PAL_CODE: e820_type = E820_TYPE_RESERVED; break; case EFI_UNUSABLE_MEMORY: e820_type = E820_TYPE_UNUSABLE; break; case EFI_ACPI_RECLAIM_MEMORY: e820_type = E820_TYPE_ACPI; break; case EFI_LOADER_CODE: case EFI_LOADER_DATA: case EFI_BOOT_SERVICES_CODE: case EFI_BOOT_SERVICES_DATA: case EFI_CONVENTIONAL_MEMORY: if (efi_soft_reserve_enabled() && (d->attribute & EFI_MEMORY_SP)) e820_type = E820_TYPE_SOFT_RESERVED; else e820_type = E820_TYPE_RAM; break; case EFI_ACPI_MEMORY_NVS: e820_type = E820_TYPE_NVS; break; case EFI_PERSISTENT_MEMORY: e820_type = E820_TYPE_PMEM; break; default: continue; } /* Merge adjacent mappings */ if (prev && prev->type == e820_type && (prev->addr + prev->size) == d->phys_addr) { prev->size += d->num_pages << 12; continue; } if (nr_entries == ARRAY_SIZE(params->e820_table)) { u32 need = (nr_desc - i) * sizeof(struct e820_entry) + sizeof(struct setup_data); if (!e820ext || e820ext_size < need) return EFI_BUFFER_TOO_SMALL; /* boot_params map full, switch to e820 extended */ entry = (struct boot_e820_entry *)e820ext->data; } entry->addr = d->phys_addr; entry->size = d->num_pages << PAGE_SHIFT; entry->type = e820_type; prev = entry++; nr_entries++; } if (nr_entries > ARRAY_SIZE(params->e820_table)) { u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); add_e820ext(params, e820ext, nr_e820ext); nr_entries -= nr_e820ext; } params->e820_entries = (u8)nr_entries; return EFI_SUCCESS; } static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, u32 *e820ext_size) { efi_status_t status; unsigned long size; size = sizeof(struct setup_data) + sizeof(struct e820_entry) * nr_desc; if (*e820ext) { efi_bs_call(free_pool, *e820ext); *e820ext = NULL; *e820ext_size = 0; } status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)e820ext); if (status == EFI_SUCCESS) *e820ext_size = size; return status; } static efi_status_t allocate_e820(struct boot_params *params, struct setup_data **e820ext, u32 *e820ext_size) { unsigned long map_size, desc_size, map_key; efi_status_t status; __u32 nr_desc, desc_version; /* Only need the size of the mem map and size of each mem descriptor */ map_size = 0; status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key, &desc_size, &desc_version); if (status != EFI_BUFFER_TOO_SMALL) return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED; nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS; if (nr_desc > ARRAY_SIZE(params->e820_table)) { u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table); status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); if (status != EFI_SUCCESS) return status; } return EFI_SUCCESS; } struct exit_boot_struct { struct boot_params *boot_params; struct efi_info *efi; }; static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) { const char *signature; struct exit_boot_struct *p = priv; signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE : EFI32_LOADER_SIGNATURE; memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); efi_set_u64_split((unsigned long)efi_system_table, &p->efi->efi_systab, &p->efi->efi_systab_hi); p->efi->efi_memdesc_size = *map->desc_size; p->efi->efi_memdesc_version = *map->desc_ver; efi_set_u64_split((unsigned long)*map->map, &p->efi->efi_memmap, &p->efi->efi_memmap_hi); p->efi->efi_memmap_size = *map->map_size; return EFI_SUCCESS; } static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) { unsigned long map_sz, key, desc_size, buff_size; efi_memory_desc_t *mem_map; struct setup_data *e820ext = NULL; __u32 e820ext_size = 0; efi_status_t status; __u32 desc_version; struct efi_boot_memmap map; struct exit_boot_struct priv; map.map = &mem_map; map.map_size = &map_sz; map.desc_size = &desc_size; map.desc_ver = &desc_version; map.key_ptr = &key; map.buff_size = &buff_size; priv.boot_params = boot_params; priv.efi = &boot_params->efi_info; status = allocate_e820(boot_params, &e820ext, &e820ext_size); if (status != EFI_SUCCESS) return status; /* Might as well exit boot services now */ status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func); if (status != EFI_SUCCESS) return status; /* Historic? */ boot_params->alt_mem_k = 32 * 1024; status = setup_e820(boot_params, e820ext, e820ext_size); if (status != EFI_SUCCESS) return status; return EFI_SUCCESS; } /* * On success, we return the address of startup_32, which has potentially been * relocated by efi_relocate_kernel. * On failure, we exit to the firmware via efi_exit instead of returning. */ unsigned long efi_main(efi_handle_t handle, efi_system_table_t *sys_table_arg, struct boot_params *boot_params) { unsigned long bzimage_addr = (unsigned long)startup_32; unsigned long buffer_start, buffer_end; struct setup_header *hdr = &boot_params->hdr; efi_status_t status; efi_system_table = sys_table_arg; /* Check if we were booted by the EFI firmware */ if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) efi_exit(handle, EFI_INVALID_PARAMETER); /* * If the kernel isn't already loaded at a suitable address, * relocate it. * * It must be loaded above LOAD_PHYSICAL_ADDR. * * The maximum address for 64-bit is 1 << 46 for 4-level paging. This * is defined as the macro MAXMEM, but unfortunately that is not a * compile-time constant if 5-level paging is configured, so we instead * define our own macro for use here. * * For 32-bit, the maximum address is complicated to figure out, for * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what * KASLR uses. * * Also relocate it if image_offset is zero, i.e. the kernel wasn't * loaded by LoadImage, but rather by a bootloader that called the * handover entry. The reason we must always relocate in this case is * to handle the case of systemd-boot booting a unified kernel image, * which is a PE executable that contains the bzImage and an initrd as * COFF sections. The initrd section is placed after the bzImage * without ensuring that there are at least init_size bytes available * for the bzImage, and thus the compressed kernel's startup code may * overwrite the initrd unless it is moved out of the way. */ buffer_start = ALIGN(bzimage_addr - image_offset, hdr->kernel_alignment); buffer_end = buffer_start + hdr->init_size; if ((buffer_start < LOAD_PHYSICAL_ADDR) || (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE) || (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) || (image_offset == 0)) { extern char _bss[]; status = efi_relocate_kernel(&bzimage_addr, (unsigned long)_bss - bzimage_addr, hdr->init_size, hdr->pref_address, hdr->kernel_alignment, LOAD_PHYSICAL_ADDR); if (status != EFI_SUCCESS) { efi_err("efi_relocate_kernel() failed!\n"); goto fail; } /* * Now that we've copied the kernel elsewhere, we no longer * have a set up block before startup_32(), so reset image_offset * to zero in case it was set earlier. */ image_offset = 0; } #ifdef CONFIG_CMDLINE_BOOL status = efi_parse_options(CONFIG_CMDLINE); if (status != EFI_SUCCESS) { efi_err("Failed to parse options\n"); goto fail; } #endif if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | ((u64)boot_params->ext_cmd_line_ptr << 32)); status = efi_parse_options((char *)cmdline_paddr); if (status != EFI_SUCCESS) { efi_err("Failed to parse options\n"); goto fail; } } /* * At this point, an initrd may already have been loaded by the * bootloader and passed via bootparams. We permit an initrd loaded * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. * * If the device path is not present, any command-line initrd= * arguments will be processed only if image is not NULL, which will be * the case only if we were loaded via the PE entry point. */ if (!efi_noinitrd) { unsigned long addr, size; status = efi_load_initrd(image, &addr, &size, hdr->initrd_addr_max, ULONG_MAX); if (status != EFI_SUCCESS) { efi_err("Failed to load initrd!\n"); goto fail; } if (size > 0) { efi_set_u64_split(addr, &hdr->ramdisk_image, &boot_params->ext_ramdisk_image); efi_set_u64_split(size, &hdr->ramdisk_size, &boot_params->ext_ramdisk_size); } } /* * If the boot loader gave us a value for secure_boot then we use that, * otherwise we ask the BIOS. */ if (boot_params->secure_boot == efi_secureboot_mode_unset) boot_params->secure_boot = efi_get_secureboot(); /* Ask the firmware to clear memory on unclean shutdown */ efi_enable_reset_attack_mitigation(); efi_random_get_seed(); efi_retrieve_tpm2_eventlog(); setup_graphics(boot_params); setup_efi_pci(boot_params); setup_quirks(boot_params); status = exit_boot(boot_params, handle); if (status != EFI_SUCCESS) { efi_err("exit_boot() failed!\n"); goto fail; } return bzimage_addr; fail: efi_err("efi_main() failed!\n"); efi_exit(handle, status); }