2 * Copyright 2012 Intel Corporation
3 * Author: Josh Triplett <josh@joshtriplett.org>
5 * Based on the bgrt driver:
6 * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
7 * Author: Matthew Garrett
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/acpi.h>
19 #include <linux/efi.h>
20 #include <linux/efi-bgrt.h>
22 struct acpi_table_bgrt bgrt_tab;
23 size_t __initdata bgrt_image_size;
30 static bool efi_bgrt_addr_valid(u64 addr)
32 efi_memory_desc_t *md;
34 for_each_efi_memory_desc(md) {
38 if (md->type != EFI_BOOT_SERVICES_DATA)
41 size = md->num_pages << EFI_PAGE_SHIFT;
42 end = md->phys_addr + size;
43 if (addr >= md->phys_addr && addr < end)
50 void __init efi_bgrt_init(struct acpi_table_header *table)
53 struct bmp_header bmp_header;
54 struct acpi_table_bgrt *bgrt = &bgrt_tab;
59 if (!efi_enabled(EFI_MEMMAP))
62 if (table->length < sizeof(bgrt_tab)) {
63 pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n",
64 table->length, sizeof(bgrt_tab));
67 *bgrt = *(struct acpi_table_bgrt *)table;
68 if (bgrt->version != 1) {
69 pr_notice("Ignoring BGRT: invalid version %u (expected 1)\n",
73 if (bgrt->status & 0xfe) {
74 pr_notice("Ignoring BGRT: reserved status bits are non-zero %u\n",
78 if (bgrt->image_type != 0) {
79 pr_notice("Ignoring BGRT: invalid image type %u (expected 0)\n",
83 if (!bgrt->image_address) {
84 pr_notice("Ignoring BGRT: null image address\n");
88 if (!efi_bgrt_addr_valid(bgrt->image_address)) {
89 pr_notice("Ignoring BGRT: invalid image address\n");
92 image = early_memremap(bgrt->image_address, sizeof(bmp_header));
94 pr_notice("Ignoring BGRT: failed to map image header memory\n");
98 memcpy(&bmp_header, image, sizeof(bmp_header));
99 early_memunmap(image, sizeof(bmp_header));
100 if (bmp_header.id != 0x4d42) {
101 pr_notice("Ignoring BGRT: Incorrect BMP magic number 0x%x (expected 0x4d42)\n",
105 bgrt_image_size = bmp_header.size;
106 efi_mem_reserve(bgrt->image_address, bgrt_image_size);
110 memset(bgrt, 0, sizeof(bgrt_tab));