u-boot/boot/bootmeth_efi.c
Simon Glass acfa9bdfa7 bootstd: Add an implementation of EFI boot
Add a bootmeth driver which handles EFI boot, using EFI_LOADER.

In effect, this provides the same functionality as the 'bootefi' command
and shares the same code. But the interface into it is via a bootmeth,
so it does not require any special scripts, etc.

For now this requires the 'bootefi' command be enabled. Future work may
tidy this up so that it can be used without CONFIG_CMDLINE being enabled.

There was much discussion about whether this is needed, but it seems
that it is, at least for now.

Signed-off-by: Simon Glass <sjg@chromium.org>
2022-04-25 10:00:04 -04:00

189 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Bootmethod for distro boot via EFI
*
* Copyright 2021 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#define LOG_CATEGORY UCLASS_BOOTSTD
#include <common.h>
#include <bootdev.h>
#include <bootflow.h>
#include <bootmeth.h>
#include <command.h>
#include <dm.h>
#include <efi_loader.h>
#include <fs.h>
#include <malloc.h>
#include <mapmem.h>
#include <mmc.h>
#include <pxe_utils.h>
#define EFI_DIRNAME "efi/boot/"
/**
* get_efi_leafname() - Get the leaf name for the EFI file we expect
*
* @str: Place to put leaf name for this architecture, e.g. "bootaa64.efi".
* Must have at least 16 bytes of space
* @max_len: Length of @str, must be >=16
*/
static int get_efi_leafname(char *str, int max_len)
{
const char *base;
if (max_len < 16)
return log_msg_ret("spc", -ENOSPC);
if (IS_ENABLED(CONFIG_ARM64))
base = "bootaa64";
else if (IS_ENABLED(CONFIG_ARM))
base = "bootarm";
else if (IS_ENABLED(CONFIG_X86_RUN_32BIT))
base = "bootia32";
else if (IS_ENABLED(CONFIG_X86_RUN_64BIT))
base = "bootx64";
else if (IS_ENABLED(CONFIG_ARCH_RV32I))
base = "bootriscv32";
else if (IS_ENABLED(CONFIG_ARCH_RV64I))
base = "bootriscv64";
else if (IS_ENABLED(CONFIG_SANDBOX))
base = "bootsbox";
else
return -EINVAL;
strcpy(str, base);
strcat(str, ".efi");
return 0;
}
static int efiload_read_file(struct blk_desc *desc, struct bootflow *bflow)
{
const struct udevice *media_dev;
int size = bflow->size;
const char *dev_name;
char devnum_str[9];
char dirname[200];
char *last_slash;
int ret;
ret = bootmeth_alloc_file(bflow, 0x2000000, 0x10000);
if (ret)
return log_msg_ret("read", ret);
/*
* This is a horrible hack to tell EFI about this boot device. Once we
* unify EFI with the rest of U-Boot we can clean this up. The same hack
* exists in multiple places, e.g. in the fs, tftp and load commands.
*
* Once we can clean up the EFI code to make proper use of driver model,
* this can go away.
*/
media_dev = dev_get_parent(bflow->dev);
snprintf(devnum_str, sizeof(devnum_str), "%x", dev_seq(media_dev));
strlcpy(dirname, bflow->fname, sizeof(dirname));
last_slash = strrchr(dirname, '/');
if (last_slash)
*last_slash = '\0';
log_debug("setting bootdev %s, %s, %s, %p, %x\n",
dev_get_uclass_name(media_dev), devnum_str, bflow->fname,
bflow->buf, size);
dev_name = device_get_uclass_id(media_dev) == UCLASS_MASS_STORAGE ?
"usb" : dev_get_uclass_name(media_dev);
efi_set_bootdev(dev_name, devnum_str, bflow->fname, bflow->buf, size);
return 0;
}
static int distro_efi_check(struct udevice *dev, struct bootflow_iter *iter)
{
int ret;
/* This only works on block devices */
ret = bootflow_iter_uses_blk_dev(iter);
if (ret)
return log_msg_ret("blk", ret);
return 0;
}
static int distro_efi_read_bootflow(struct udevice *dev, struct bootflow *bflow)
{
struct blk_desc *desc = NULL;
char fname[sizeof(EFI_DIRNAME) + 16];
int ret;
/* We require a partition table */
if (!bflow->part)
return -ENOENT;
strcpy(fname, EFI_DIRNAME);
ret = get_efi_leafname(fname + strlen(fname),
sizeof(fname) - strlen(fname));
if (ret)
return log_msg_ret("leaf", ret);
if (bflow->blk)
desc = dev_get_uclass_plat(bflow->blk);
ret = bootmeth_try_file(bflow, desc, NULL, fname);
if (ret)
return log_msg_ret("try", ret);
ret = efiload_read_file(desc, bflow);
if (ret)
return log_msg_ret("read", -EINVAL);
return 0;
}
int distro_efi_boot(struct udevice *dev, struct bootflow *bflow)
{
char cmd[50];
/*
* At some point we can add a real interface to bootefi so we can call
* this directly. For now, go through the CLI like distro boot.
*/
snprintf(cmd, sizeof(cmd), "bootefi %lx %lx",
(ulong)map_to_sysmem(bflow->buf),
(ulong)map_to_sysmem(gd->fdt_blob));
if (run_command(cmd, 0))
return log_msg_ret("run", -EINVAL);
return 0;
}
static int distro_bootmeth_efi_bind(struct udevice *dev)
{
struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
"EFI boot from an .efi file" : "EFI";
return 0;
}
static struct bootmeth_ops distro_efi_bootmeth_ops = {
.check = distro_efi_check,
.read_bootflow = distro_efi_read_bootflow,
.read_file = bootmeth_common_read_file,
.boot = distro_efi_boot,
};
static const struct udevice_id distro_efi_bootmeth_ids[] = {
{ .compatible = "u-boot,distro-efi" },
{ }
};
U_BOOT_DRIVER(bootmeth_efi) = {
.name = "bootmeth_efi",
.id = UCLASS_BOOTMETH,
.of_match = distro_efi_bootmeth_ids,
.ops = &distro_efi_bootmeth_ops,
.bind = distro_bootmeth_efi_bind,
};