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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * Copyright (c) 2020, Linaro Limited
- */
- #include <common.h>
- #include <env.h>
- #include <malloc.h>
- #include <mapmem.h>
- #include <dm.h>
- #include <fs.h>
- #include <efi_loader.h>
- #include <efi_load_initrd.h>
- static const efi_guid_t efi_guid_load_file2_protocol =
- EFI_LOAD_FILE2_PROTOCOL_GUID;
- static efi_status_t EFIAPI
- efi_load_file2_initrd(struct efi_load_file_protocol *this,
- struct efi_device_path *file_path, bool boot_policy,
- efi_uintn_t *buffer_size, void *buffer);
- static const struct efi_load_file_protocol efi_lf2_protocol = {
- .load_file = efi_load_file2_initrd,
- };
- /*
- * Device path defined by Linux to identify the handle providing the
- * EFI_LOAD_FILE2_PROTOCOL used for loading the initial ramdisk.
- */
- static const struct efi_initrd_dp dp = {
- .vendor = {
- {
- DEVICE_PATH_TYPE_MEDIA_DEVICE,
- DEVICE_PATH_SUB_TYPE_VENDOR_PATH,
- sizeof(dp.vendor),
- },
- EFI_INITRD_MEDIA_GUID,
- },
- .end = {
- DEVICE_PATH_TYPE_END,
- DEVICE_PATH_SUB_TYPE_END,
- sizeof(dp.end),
- }
- };
- /**
- * get_file_size() - retrieve the size of initramfs, set efi status on error
- *
- * @dev: device to read from, e.g. "mmc"
- * @part: device partition, e.g. "0:1"
- * @file: name of file
- * @status: EFI exit code in case of failure
- *
- * Return: size of file
- */
- static loff_t get_file_size(const char *dev, const char *part, const char *file,
- efi_status_t *status)
- {
- loff_t sz = 0;
- int ret;
- ret = fs_set_blk_dev(dev, part, FS_TYPE_ANY);
- if (ret) {
- *status = EFI_NO_MEDIA;
- goto out;
- }
- ret = fs_size(file, &sz);
- if (ret) {
- sz = 0;
- *status = EFI_NOT_FOUND;
- goto out;
- }
- out:
- return sz;
- }
- /**
- * efi_load_file2initrd() - load initial RAM disk
- *
- * This function implements the LoadFile service of the EFI_LOAD_FILE2_PROTOCOL
- * in order to load an initial RAM disk requested by the Linux kernel stub.
- *
- * See the UEFI spec for details.
- *
- * @this: EFI_LOAD_FILE2_PROTOCOL instance
- * @file_path: media device path of the file, "" in this case
- * @boot_policy: must be false
- * @buffer_size: size of allocated buffer
- * @buffer: buffer to load the file
- *
- * Return: status code
- */
- static efi_status_t EFIAPI
- efi_load_file2_initrd(struct efi_load_file_protocol *this,
- struct efi_device_path *file_path, bool boot_policy,
- efi_uintn_t *buffer_size, void *buffer)
- {
- const char *filespec = CONFIG_EFI_INITRD_FILESPEC;
- efi_status_t status = EFI_NOT_FOUND;
- loff_t file_sz = 0, read_sz = 0;
- char *dev, *part, *file;
- char *s;
- int ret;
- EFI_ENTRY("%p, %p, %d, %p, %p", this, file_path, boot_policy,
- buffer_size, buffer);
- s = strdup(filespec);
- if (!s)
- goto out;
- if (!this || this != &efi_lf2_protocol ||
- !buffer_size) {
- status = EFI_INVALID_PARAMETER;
- goto out;
- }
- if (file_path->type != dp.end.type ||
- file_path->sub_type != dp.end.sub_type) {
- status = EFI_INVALID_PARAMETER;
- goto out;
- }
- if (boot_policy) {
- status = EFI_UNSUPPORTED;
- goto out;
- }
- /*
- * expect a string with three space separated parts:
- *
- * * a block device type, e.g. "mmc"
- * * a device and partition identifier, e.g. "0:1"
- * * a file path on the block device, e.g. "/boot/initrd.cpio.gz"
- */
- dev = strsep(&s, " ");
- if (!dev)
- goto out;
- part = strsep(&s, " ");
- if (!part)
- goto out;
- file = strsep(&s, " ");
- if (!file)
- goto out;
- file_sz = get_file_size(dev, part, file, &status);
- if (!file_sz)
- goto out;
- if (!buffer || *buffer_size < file_sz) {
- status = EFI_BUFFER_TOO_SMALL;
- *buffer_size = file_sz;
- } else {
- ret = fs_set_blk_dev(dev, part, FS_TYPE_ANY);
- if (ret) {
- status = EFI_NO_MEDIA;
- goto out;
- }
- ret = fs_read(file, map_to_sysmem(buffer), 0, *buffer_size,
- &read_sz);
- if (ret || read_sz != file_sz)
- goto out;
- *buffer_size = read_sz;
- status = EFI_SUCCESS;
- }
- out:
- free(s);
- return EFI_EXIT(status);
- }
- /**
- * efi_initrd_register() - create handle for loading initial RAM disk
- *
- * This function creates a new handle and installs a Linux specific vendor
- * device path and an EFI_LOAD_FILE_2_PROTOCOL. Linux uses the device path
- * to identify the handle and then calls the LoadFile service of the
- * EFI_LOAD_FILE_2_PROTOCOL to read the initial RAM disk.
- *
- * Return: status code
- */
- efi_status_t efi_initrd_register(void)
- {
- efi_handle_t efi_initrd_handle = NULL;
- efi_status_t ret;
- ret = EFI_CALL(efi_install_multiple_protocol_interfaces
- (&efi_initrd_handle,
- /* initramfs */
- &efi_guid_device_path, &dp,
- /* LOAD_FILE2 */
- &efi_guid_load_file2_protocol,
- (void *)&efi_lf2_protocol,
- NULL));
- return ret;
- }
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