u-boot/boot/bootmeth_script.c
Sean Anderson bcc85b96b5 cmd: source: Support specifying config name
As discussed previously [1,2], the source command is not safe to use with
verified boot unless there is a key with required = "images" (which has its
own problems). This is because if such a key is absent, signatures are
verified but not required. It is assumed that configuration nodes will
provide the signature. Because the source command does not use
configurations to determine the image to source, effectively no
verification takes place.

To address this, allow specifying configuration nodes. We use the same
syntax as the bootm command (helpfully provided for us by fit_parse_conf).
By default, we first try the default config and then the default image. To
force using a config, # must be present in the command (e.g. `source
$loadaddr#my-conf`). For convenience, the config may be omitted, just like
the address may be (e.g. `source \#`). This also works for images
(`source :` behaves exactly like `source` currently does).

[1] https://lore.kernel.org/u-boot/7d711133-d513-5bcb-52f2-a9dbaa9eeded@prevas.dk/
[2] https://lore.kernel.org/u-boot/042dcb34-f85f-351e-1b0e-513f89005fdd@gmail.com/

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2022-12-31 13:35:19 -05:00

140 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Bootmethod for booting via a U-Boot script
*
* Copyright 2021 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#define LOG_CATEGORY UCLASS_BOOTSTD
#include <common.h>
#include <blk.h>
#include <bootflow.h>
#include <bootmeth.h>
#include <bootstd.h>
#include <dm.h>
#include <env.h>
#include <fs.h>
#include <image.h>
#include <malloc.h>
#include <mapmem.h>
#define SCRIPT_FNAME1 "boot.scr.uimg"
#define SCRIPT_FNAME2 "boot.scr"
static int script_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 script_read_bootflow(struct udevice *dev, struct bootflow *bflow)
{
struct blk_desc *desc = NULL;
const char *const *prefixes;
struct udevice *bootstd;
const char *prefix;
int ret, i;
ret = uclass_first_device_err(UCLASS_BOOTSTD, &bootstd);
if (ret)
return log_msg_ret("std", ret);
/* We require a partition table */
if (!bflow->part)
return -ENOENT;
if (bflow->blk)
desc = dev_get_uclass_plat(bflow->blk);
prefixes = bootstd_get_prefixes(bootstd);
i = 0;
do {
prefix = prefixes ? prefixes[i] : NULL;
ret = bootmeth_try_file(bflow, desc, prefix, SCRIPT_FNAME1);
if (ret)
ret = bootmeth_try_file(bflow, desc, prefix,
SCRIPT_FNAME2);
} while (ret && prefixes && prefixes[++i]);
if (ret)
return log_msg_ret("try", ret);
bflow->subdir = strdup(prefix ? prefix : "");
if (!bflow->subdir)
return log_msg_ret("prefix", -ENOMEM);
ret = bootmeth_alloc_file(bflow, 0x10000, 1);
if (ret)
return log_msg_ret("read", ret);
return 0;
}
static int script_boot(struct udevice *dev, struct bootflow *bflow)
{
struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
ulong addr;
int ret;
ret = env_set("devtype", blk_get_devtype(bflow->blk));
if (!ret)
ret = env_set_hex("devnum", desc->devnum);
if (!ret)
ret = env_set("prefix", bflow->subdir);
if (!ret && IS_ENABLED(CONFIG_ARCH_SUNXI) &&
!strcmp("mmc", blk_get_devtype(bflow->blk)))
ret = env_set_hex("mmc_bootdev", desc->devnum);
if (ret)
return log_msg_ret("env", ret);
log_debug("devtype: %s\n", env_get("devtype"));
log_debug("devnum: %s\n", env_get("devnum"));
log_debug("prefix: %s\n", env_get("prefix"));
log_debug("mmc_bootdev: %s\n", env_get("mmc_bootdev"));
addr = map_to_sysmem(bflow->buf);
ret = image_source_script(addr, NULL, NULL);
if (ret)
return log_msg_ret("boot", ret);
return 0;
}
static int script_bootmeth_bind(struct udevice *dev)
{
struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
"Script boot from a block device" : "script";
return 0;
}
static struct bootmeth_ops script_bootmeth_ops = {
.check = script_check,
.read_bootflow = script_read_bootflow,
.read_file = bootmeth_common_read_file,
.boot = script_boot,
};
static const struct udevice_id script_bootmeth_ids[] = {
{ .compatible = "u-boot,script" },
{ }
};
U_BOOT_DRIVER(bootmeth_script) = {
.name = "bootmeth_script",
.id = UCLASS_BOOTMETH,
.of_match = script_bootmeth_ids,
.ops = &script_bootmeth_ops,
.bind = script_bootmeth_bind,
};