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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/firmware/efi/efi-bgrt.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/firmware/efi/efi-bgrt.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c new file mode 100644 index 000000000..6aafdb67d --- /dev/null +++ b/drivers/firmware/efi/efi-bgrt.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 + */ + +#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 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_MEMMAP)) + 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; + /* + * Only version 1 is defined but some older laptops (seen on Lenovo + * Ivy Bridge models) have a correct version 1 BGRT table with the + * version set to 0, so we accept version 0 and 1. + */ + if (bgrt->version > 1) { + pr_notice("Ignoring BGRT: invalid version %u (expected 1)\n", + bgrt->version); + 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; + } + + if (efi_mem_type(bgrt->image_address) != EFI_BOOT_SERVICES_DATA) { + pr_notice("Ignoring BGRT: invalid 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)); +} |