mirror of https://gitee.com/openkylin/linux.git
88 lines
2.1 KiB
C
88 lines
2.1 KiB
C
/*
|
|
* Copyright 2012 Intel Corporation
|
|
* Author: Josh Triplett <josh@joshtriplett.org>
|
|
*
|
|
* Based on the bgrt driver:
|
|
* Copyright 2012 Red Hat, Inc <mjg@redhat.com>
|
|
* Author: Matthew Garrett
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/acpi.h>
|
|
#include <linux/efi.h>
|
|
#include <linux/efi-bgrt.h>
|
|
|
|
struct acpi_table_bgrt bgrt_tab;
|
|
size_t __initdata bgrt_image_size;
|
|
|
|
struct bmp_header {
|
|
u16 id;
|
|
u32 size;
|
|
} __packed;
|
|
|
|
void __init efi_bgrt_init(struct acpi_table_header *table)
|
|
{
|
|
void *image;
|
|
struct bmp_header bmp_header;
|
|
struct acpi_table_bgrt *bgrt = &bgrt_tab;
|
|
|
|
if (acpi_disabled)
|
|
return;
|
|
|
|
if (!efi_enabled(EFI_BOOT))
|
|
return;
|
|
|
|
if (table->length < sizeof(bgrt_tab)) {
|
|
pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n",
|
|
table->length, sizeof(bgrt_tab));
|
|
return;
|
|
}
|
|
*bgrt = *(struct acpi_table_bgrt *)table;
|
|
if (bgrt->version != 1) {
|
|
pr_notice("Ignoring BGRT: invalid version %u (expected 1)\n",
|
|
bgrt->version);
|
|
goto out;
|
|
}
|
|
if (bgrt->status & 0xfe) {
|
|
pr_notice("Ignoring BGRT: reserved status bits are non-zero %u\n",
|
|
bgrt->status);
|
|
goto out;
|
|
}
|
|
if (bgrt->image_type != 0) {
|
|
pr_notice("Ignoring BGRT: invalid image type %u (expected 0)\n",
|
|
bgrt->image_type);
|
|
goto out;
|
|
}
|
|
if (!bgrt->image_address) {
|
|
pr_notice("Ignoring BGRT: null image address\n");
|
|
goto out;
|
|
}
|
|
|
|
image = early_memremap(bgrt->image_address, sizeof(bmp_header));
|
|
if (!image) {
|
|
pr_notice("Ignoring BGRT: failed to map image header memory\n");
|
|
goto out;
|
|
}
|
|
|
|
memcpy(&bmp_header, image, sizeof(bmp_header));
|
|
early_memunmap(image, sizeof(bmp_header));
|
|
if (bmp_header.id != 0x4d42) {
|
|
pr_notice("Ignoring BGRT: Incorrect BMP magic number 0x%x (expected 0x4d42)\n",
|
|
bmp_header.id);
|
|
goto out;
|
|
}
|
|
bgrt_image_size = bmp_header.size;
|
|
efi_mem_reserve(bgrt->image_address, bgrt_image_size);
|
|
|
|
return;
|
|
out:
|
|
memset(bgrt, 0, sizeof(bgrt_tab));
|
|
}
|