2 * Extensible Firmware Interface
4 * Based on Extensible Firmware Interface Specification version 2.4
6 * Copyright (C) 2013 - 2015 Linaro Ltd.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
14 #define pr_fmt(fmt) "efi: " fmt
16 #include <linux/efi.h>
17 #include <linux/init.h>
18 #include <linux/memblock.h>
19 #include <linux/mm_types.h>
21 #include <linux/of_fdt.h>
22 #include <linux/platform_device.h>
23 #include <linux/screen_info.h>
29 static int __init is_normal_ram(efi_memory_desc_t *md)
31 if (md->attribute & EFI_MEMORY_WB)
37 * Translate a EFI virtual address into a physical address: this is necessary,
38 * as some data members of the EFI system table are virtually remapped after
39 * SetVirtualAddressMap() has been called.
41 static phys_addr_t efi_to_phys(unsigned long addr)
43 efi_memory_desc_t *md;
45 for_each_efi_memory_desc(md) {
46 if (!(md->attribute & EFI_MEMORY_RUNTIME))
48 if (md->virt_addr == 0)
49 /* no virtual mapping has been installed by the stub */
51 if (md->virt_addr <= addr &&
52 (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
53 return md->phys_addr + addr - md->virt_addr;
58 static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
60 static __initdata efi_config_table_type_t arch_tables[] = {
61 {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
62 {NULL_GUID, NULL, NULL}
65 static void __init init_screen_info(void)
67 struct screen_info *si;
69 if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
70 si = early_memremap_ro(screen_info_table, sizeof(*si));
72 pr_err("Could not map screen_info config table\n");
76 early_memunmap(si, sizeof(*si));
78 /* dummycon on ARM needs non-zero values for columns/lines */
79 screen_info.orig_video_cols = 80;
80 screen_info.orig_video_lines = 25;
83 if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
84 memblock_is_map_memory(screen_info.lfb_base))
85 memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
88 static int __init uefi_init(void)
93 char vendor[100] = "unknown";
96 efi.systab = early_memremap_ro(efi_system_table,
97 sizeof(efi_system_table_t));
98 if (efi.systab == NULL) {
99 pr_warn("Unable to map EFI system table.\n");
103 set_bit(EFI_BOOT, &efi.flags);
104 if (IS_ENABLED(CONFIG_64BIT))
105 set_bit(EFI_64BIT, &efi.flags);
108 * Verify the EFI Table
110 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
111 pr_err("System table signature incorrect\n");
115 if ((efi.systab->hdr.revision >> 16) < 2)
116 pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
117 efi.systab->hdr.revision >> 16,
118 efi.systab->hdr.revision & 0xffff);
120 efi.runtime_version = efi.systab->hdr.revision;
122 /* Show what we know for posterity */
123 c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
124 sizeof(vendor) * sizeof(efi_char16_t));
126 for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
129 early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
132 pr_info("EFI v%u.%.02u by %s\n",
133 efi.systab->hdr.revision >> 16,
134 efi.systab->hdr.revision & 0xffff, vendor);
136 table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
137 config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
139 if (config_tables == NULL) {
140 pr_warn("Unable to map EFI config table array.\n");
144 retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
145 sizeof(efi_config_table_t),
148 early_memunmap(config_tables, table_size);
150 early_memunmap(efi.systab, sizeof(efi_system_table_t));
155 * Return true for RAM regions we want to permanently reserve.
157 static __init int is_reserve_region(efi_memory_desc_t *md)
160 case EFI_LOADER_CODE:
161 case EFI_LOADER_DATA:
162 case EFI_BOOT_SERVICES_CODE:
163 case EFI_BOOT_SERVICES_DATA:
164 case EFI_CONVENTIONAL_MEMORY:
165 case EFI_PERSISTENT_MEMORY:
170 return is_normal_ram(md);
173 static __init void reserve_regions(void)
175 efi_memory_desc_t *md;
176 u64 paddr, npages, size;
178 if (efi_enabled(EFI_DBG))
179 pr_info("Processing EFI memory map:\n");
181 for_each_efi_memory_desc(md) {
182 paddr = md->phys_addr;
183 npages = md->num_pages;
185 if (efi_enabled(EFI_DBG)) {
188 pr_info(" 0x%012llx-0x%012llx %s",
189 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
190 efi_md_typeattr_format(buf, sizeof(buf), md));
193 memrange_efi_to_native(&paddr, &npages);
194 size = npages << PAGE_SHIFT;
196 if (is_normal_ram(md))
197 early_init_dt_add_memory_arch(paddr, size);
199 if (is_reserve_region(md)) {
200 memblock_mark_nomap(paddr, size);
201 if (efi_enabled(EFI_DBG))
205 if (efi_enabled(EFI_DBG))
209 set_bit(EFI_MEMMAP, &efi.flags);
212 void __init efi_init(void)
214 struct efi_fdt_params params;
216 /* Grab UEFI information placed in FDT by stub */
217 if (!efi_get_fdt_params(¶ms))
220 efi_system_table = params.system_table;
222 efi.memmap.phys_map = params.mmap;
223 efi.memmap.map = early_memremap_ro(params.mmap, params.mmap_size);
224 if (efi.memmap.map == NULL) {
226 * If we are booting via UEFI, the UEFI memory map is the only
227 * description of memory we have, so there is little point in
228 * proceeding if we cannot access it.
230 panic("Unable to map EFI memory map.\n");
232 efi.memmap.map_end = efi.memmap.map + params.mmap_size;
233 efi.memmap.desc_size = params.desc_size;
234 efi.memmap.desc_version = params.desc_ver;
236 WARN(efi.memmap.desc_version != 1,
237 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
238 efi.memmap.desc_version);
245 early_memunmap(efi.memmap.map, params.mmap_size);
247 memblock_reserve(params.mmap & PAGE_MASK,
248 PAGE_ALIGN(params.mmap_size +
249 (params.mmap & ~PAGE_MASK)));
254 static int __init register_gop_device(void)
258 if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
261 pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
262 &screen_info, sizeof(screen_info));
263 return PTR_ERR_OR_ZERO(pd);
265 subsys_initcall(register_gop_device);