| // SPDX-License-Identifier: GPL-2.0-only |
| |
| /* ----------------------------------------------------------------------- |
| * |
| * Copyright 2011 Intel Corporation; author Matt Fleming |
| * |
| * ----------------------------------------------------------------------- */ |
| |
| #include <linux/efi.h> |
| #include <linux/pci.h> |
| #include <linux/stddef.h> |
| |
| #include <asm/efi.h> |
| #include <asm/e820/types.h> |
| #include <asm/setup.h> |
| #include <asm/desc.h> |
| #include <asm/boot.h> |
| |
| #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; |
| |
| 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); |
| } |