| /* |
| * EFI stub implementation that is shared by arm and arm64 architectures. |
| * This should be #included by the EFI stub implementation files. |
| * |
| * Copyright (C) 2013,2014 Linaro Limited |
| * Roy Franz <roy.franz@linaro.org |
| * Copyright (C) 2013 Red Hat, Inc. |
| * Mark Salter <msalter@redhat.com> |
| * |
| * This file is part of the Linux kernel, and is made available under the |
| * terms of the GNU General Public License version 2. |
| * |
| */ |
| |
| #include <linux/efi.h> |
| #include <linux/sort.h> |
| #include <asm/efi.h> |
| |
| #include "efistub.h" |
| |
| static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg) |
| { |
| static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID; |
| static efi_char16_t const var_name[] = { |
| 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 }; |
| |
| efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable; |
| unsigned long size = sizeof(u8); |
| efi_status_t status; |
| u8 val; |
| |
| status = f_getvar((efi_char16_t *)var_name, (efi_guid_t *)&var_guid, |
| NULL, &size, &val); |
| |
| switch (status) { |
| case EFI_SUCCESS: |
| return val; |
| case EFI_NOT_FOUND: |
| return 0; |
| default: |
| return 1; |
| } |
| } |
| |
| efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, |
| void *__image, void **__fh) |
| { |
| efi_file_io_interface_t *io; |
| efi_loaded_image_t *image = __image; |
| efi_file_handle_t *fh; |
| efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID; |
| efi_status_t status; |
| void *handle = (void *)(unsigned long)image->device_handle; |
| |
| status = sys_table_arg->boottime->handle_protocol(handle, |
| &fs_proto, (void **)&io); |
| if (status != EFI_SUCCESS) { |
| efi_printk(sys_table_arg, "Failed to handle fs_proto\n"); |
| return status; |
| } |
| |
| status = io->open_volume(io, &fh); |
| if (status != EFI_SUCCESS) |
| efi_printk(sys_table_arg, "Failed to open volume\n"); |
| |
| *__fh = fh; |
| return status; |
| } |
| |
| efi_status_t efi_file_close(void *handle) |
| { |
| efi_file_handle_t *fh = handle; |
| |
| return fh->close(handle); |
| } |
| |
| efi_status_t |
| efi_file_read(void *handle, unsigned long *size, void *addr) |
| { |
| efi_file_handle_t *fh = handle; |
| |
| return fh->read(handle, size, addr); |
| } |
| |
| |
| efi_status_t |
| efi_file_size(efi_system_table_t *sys_table_arg, void *__fh, |
| efi_char16_t *filename_16, void **handle, u64 *file_sz) |
| { |
| efi_file_handle_t *h, *fh = __fh; |
| efi_file_info_t *info; |
| efi_status_t status; |
| efi_guid_t info_guid = EFI_FILE_INFO_ID; |
| unsigned long info_sz; |
| |
| status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0); |
| if (status != EFI_SUCCESS) { |
| efi_printk(sys_table_arg, "Failed to open file: "); |
| efi_char16_printk(sys_table_arg, filename_16); |
| efi_printk(sys_table_arg, "\n"); |
| return status; |
| } |
| |
| *handle = h; |
| |
| info_sz = 0; |
| status = h->get_info(h, &info_guid, &info_sz, NULL); |
| if (status != EFI_BUFFER_TOO_SMALL) { |
| efi_printk(sys_table_arg, "Failed to get file info size\n"); |
| return status; |
| } |
| |
| grow: |
| status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA, |
| info_sz, (void **)&info); |
| if (status != EFI_SUCCESS) { |
| efi_printk(sys_table_arg, "Failed to alloc mem for file info\n"); |
| return status; |
| } |
| |
| status = h->get_info(h, &info_guid, &info_sz, |
| info); |
| if (status == EFI_BUFFER_TOO_SMALL) { |
| sys_table_arg->boottime->free_pool(info); |
| goto grow; |
| } |
| |
| *file_sz = info->file_size; |
| sys_table_arg->boottime->free_pool(info); |
| |
| if (status != EFI_SUCCESS) |
| efi_printk(sys_table_arg, "Failed to get initrd info\n"); |
| |
| return status; |
| } |
| |
| |
| |
| void efi_char16_printk(efi_system_table_t *sys_table_arg, |
| efi_char16_t *str) |
| { |
| struct efi_simple_text_output_protocol *out; |
| |
| out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out; |
| out->output_string(out, str); |
| } |
| |
| |
| /* |
| * This function handles the architcture specific differences between arm and |
| * arm64 regarding where the kernel image must be loaded and any memory that |
| * must be reserved. On failure it is required to free all |
| * all allocations it has made. |
| */ |
| efi_status_t handle_kernel_image(efi_system_table_t *sys_table, |
| unsigned long *image_addr, |
| unsigned long *image_size, |
| unsigned long *reserve_addr, |
| unsigned long *reserve_size, |
| unsigned long dram_base, |
| efi_loaded_image_t *image); |
| /* |
| * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint |
| * that is described in the PE/COFF header. Most of the code is the same |
| * for both archictectures, with the arch-specific code provided in the |
| * handle_kernel_image() function. |
| */ |
| unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, |
| unsigned long *image_addr) |
| { |
| efi_loaded_image_t *image; |
| efi_status_t status; |
| unsigned long image_size = 0; |
| unsigned long dram_base; |
| /* addr/point and size pairs for memory management*/ |
| unsigned long initrd_addr; |
| u64 initrd_size = 0; |
| unsigned long fdt_addr = 0; /* Original DTB */ |
| unsigned long fdt_size = 0; |
| char *cmdline_ptr = NULL; |
| int cmdline_size = 0; |
| unsigned long new_fdt_addr; |
| efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID; |
| unsigned long reserve_addr = 0; |
| unsigned long reserve_size = 0; |
| |
| /* Check if we were booted by the EFI firmware */ |
| if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) |
| goto fail; |
| |
| pr_efi(sys_table, "Booting Linux Kernel...\n"); |
| |
| /* |
| * Get a handle to the loaded image protocol. This is used to get |
| * information about the running image, such as size and the command |
| * line. |
| */ |
| status = sys_table->boottime->handle_protocol(handle, |
| &loaded_image_proto, (void *)&image); |
| if (status != EFI_SUCCESS) { |
| pr_efi_err(sys_table, "Failed to get loaded image protocol\n"); |
| goto fail; |
| } |
| |
| dram_base = get_dram_base(sys_table); |
| if (dram_base == EFI_ERROR) { |
| pr_efi_err(sys_table, "Failed to find DRAM base\n"); |
| goto fail; |
| } |
| status = handle_kernel_image(sys_table, image_addr, &image_size, |
| &reserve_addr, |
| &reserve_size, |
| dram_base, image); |
| if (status != EFI_SUCCESS) { |
| pr_efi_err(sys_table, "Failed to relocate kernel\n"); |
| goto fail; |
| } |
| |
| /* |
| * Get the command line from EFI, using the LOADED_IMAGE |
| * protocol. We are going to copy the command line into the |
| * device tree, so this can be allocated anywhere. |
| */ |
| cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size); |
| if (!cmdline_ptr) { |
| pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n"); |
| goto fail_free_image; |
| } |
| |
| status = efi_parse_options(cmdline_ptr); |
| if (status != EFI_SUCCESS) |
| pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n"); |
| |
| /* |
| * Unauthenticated device tree data is a security hazard, so |
| * ignore 'dtb=' unless UEFI Secure Boot is disabled. |
| */ |
| if (efi_secureboot_enabled(sys_table)) { |
| pr_efi(sys_table, "UEFI Secure Boot is enabled.\n"); |
| } else { |
| status = handle_cmdline_files(sys_table, image, cmdline_ptr, |
| "dtb=", |
| ~0UL, &fdt_addr, &fdt_size); |
| |
| if (status != EFI_SUCCESS) { |
| pr_efi_err(sys_table, "Failed to load device tree!\n"); |
| goto fail_free_cmdline; |
| } |
| } |
| |
| if (fdt_addr) { |
| pr_efi(sys_table, "Using DTB from command line\n"); |
| } else { |
| /* Look for a device tree configuration table entry. */ |
| fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size); |
| if (fdt_addr) |
| pr_efi(sys_table, "Using DTB from configuration table\n"); |
| } |
| |
| if (!fdt_addr) |
| pr_efi(sys_table, "Generating empty DTB\n"); |
| |
| status = handle_cmdline_files(sys_table, image, cmdline_ptr, |
| "initrd=", dram_base + SZ_512M, |
| (unsigned long *)&initrd_addr, |
| (unsigned long *)&initrd_size); |
| if (status != EFI_SUCCESS) |
| pr_efi_err(sys_table, "Failed initrd from command line!\n"); |
| |
| new_fdt_addr = fdt_addr; |
| status = allocate_new_fdt_and_exit_boot(sys_table, handle, |
| &new_fdt_addr, dram_base + MAX_FDT_OFFSET, |
| initrd_addr, initrd_size, cmdline_ptr, |
| fdt_addr, fdt_size); |
| |
| /* |
| * If all went well, we need to return the FDT address to the |
| * calling function so it can be passed to kernel as part of |
| * the kernel boot protocol. |
| */ |
| if (status == EFI_SUCCESS) |
| return new_fdt_addr; |
| |
| pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n"); |
| |
| efi_free(sys_table, initrd_size, initrd_addr); |
| efi_free(sys_table, fdt_size, fdt_addr); |
| |
| fail_free_cmdline: |
| efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr); |
| |
| fail_free_image: |
| efi_free(sys_table, image_size, *image_addr); |
| efi_free(sys_table, reserve_size, reserve_addr); |
| fail: |
| return EFI_ERROR; |
| } |
| |
| /* |
| * This is the base address at which to start allocating virtual memory ranges |
| * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use |
| * any allocation we choose, and eliminate the risk of a conflict after kexec. |
| * The value chosen is the largest non-zero power of 2 suitable for this purpose |
| * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can |
| * be mapped efficiently. |
| */ |
| #define EFI_RT_VIRTUAL_BASE 0x40000000 |
| |
| static int cmp_mem_desc(const void *l, const void *r) |
| { |
| const efi_memory_desc_t *left = l, *right = r; |
| |
| return (left->phys_addr > right->phys_addr) ? 1 : -1; |
| } |
| |
| /* |
| * Returns whether region @left ends exactly where region @right starts, |
| * or false if either argument is NULL. |
| */ |
| static bool regions_are_adjacent(efi_memory_desc_t *left, |
| efi_memory_desc_t *right) |
| { |
| u64 left_end; |
| |
| if (left == NULL || right == NULL) |
| return false; |
| |
| left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE; |
| |
| return left_end == right->phys_addr; |
| } |
| |
| /* |
| * Returns whether region @left and region @right have compatible memory type |
| * mapping attributes, and are both EFI_MEMORY_RUNTIME regions. |
| */ |
| static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left, |
| efi_memory_desc_t *right) |
| { |
| static const u64 mem_type_mask = EFI_MEMORY_WB | EFI_MEMORY_WT | |
| EFI_MEMORY_WC | EFI_MEMORY_UC | |
| EFI_MEMORY_RUNTIME; |
| |
| return ((left->attribute ^ right->attribute) & mem_type_mask) == 0; |
| } |
| |
| /* |
| * efi_get_virtmap() - create a virtual mapping for the EFI memory map |
| * |
| * This function populates the virt_addr fields of all memory region descriptors |
| * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors |
| * are also copied to @runtime_map, and their total count is returned in @count. |
| */ |
| void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, |
| unsigned long desc_size, efi_memory_desc_t *runtime_map, |
| int *count) |
| { |
| u64 efi_virt_base = EFI_RT_VIRTUAL_BASE; |
| efi_memory_desc_t *in, *prev = NULL, *out = runtime_map; |
| int l; |
| |
| /* |
| * To work around potential issues with the Properties Table feature |
| * introduced in UEFI 2.5, which may split PE/COFF executable images |
| * in memory into several RuntimeServicesCode and RuntimeServicesData |
| * regions, we need to preserve the relative offsets between adjacent |
| * EFI_MEMORY_RUNTIME regions with the same memory type attributes. |
| * The easiest way to find adjacent regions is to sort the memory map |
| * before traversing it. |
| */ |
| sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc, NULL); |
| |
| for (l = 0; l < map_size; l += desc_size, prev = in) { |
| u64 paddr, size; |
| |
| in = (void *)memory_map + l; |
| if (!(in->attribute & EFI_MEMORY_RUNTIME)) |
| continue; |
| |
| paddr = in->phys_addr; |
| size = in->num_pages * EFI_PAGE_SIZE; |
| |
| /* |
| * Make the mapping compatible with 64k pages: this allows |
| * a 4k page size kernel to kexec a 64k page size kernel and |
| * vice versa. |
| */ |
| if (!regions_are_adjacent(prev, in) || |
| !regions_have_compatible_memory_type_attrs(prev, in)) { |
| |
| paddr = round_down(in->phys_addr, SZ_64K); |
| size += in->phys_addr - paddr; |
| |
| /* |
| * Avoid wasting memory on PTEs by choosing a virtual |
| * base that is compatible with section mappings if this |
| * region has the appropriate size and physical |
| * alignment. (Sections are 2 MB on 4k granule kernels) |
| */ |
| if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M) |
| efi_virt_base = round_up(efi_virt_base, SZ_2M); |
| else |
| efi_virt_base = round_up(efi_virt_base, SZ_64K); |
| } |
| |
| in->virt_addr = efi_virt_base + in->phys_addr - paddr; |
| efi_virt_base += size; |
| |
| memcpy(out, in, desc_size); |
| out = (void *)out + desc_size; |
| ++*count; |
| } |
| } |