Re: [PATCH v3 22/31] bootstd: Add an implementation of EFI boot

On 1/19/22 02:43, Simon Glass wrote:

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

Changes in v3:

• Add a log category

• Use a short name when BOOTSTD_FULL is not enabled

• Align the EFI load address

• Use common bootmeth functions

  boot/Kconfig | 21 +++++ boot/Makefile | 1 + boot/bootmeth_efi.c | 183 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 205 insertions(+) create mode 100644 boot/bootmeth_efi.c

diff --git a/boot/Kconfig b/boot/Kconfig index 61df705141d..0fee35070b0 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -338,6 +338,27 @@ config BOOTMETH_DISTRO_PXE

 This provides a way to try out standard boot on an existing boot flow.

+config BOOTMETH_EFILOADER

• bool "Bootdev support for EFI boot"

• depends on CMD_BOOTEFI

• default y

• help

•  Enables support for EFI boot using bootdevs. This makes the
  

•  bootdevs look for a 'boot<arch>.efi' on each filesystem
  

•  they scan. The resulting file is booted after enabling U-Boot's
  

•  EFI loader support.
  

•  The <arch> depends on the architecture of the board:
  

•     aa64      - aarch64 (ARM 64-bit)
  

•     arm       - ARM 32-bit
  

•     ia32      - x86 32-bit
  

•     x64       - x86 64-bit
  

•     riscv32   - RISC-V 32-bit
  

•     riscv64   - RISC-V 64-bit
  

•  This provides a way to try out standard boot on an existing boot flow.
  

• endif

  config LEGACY_IMAGE_FORMAT

diff --git a/boot/Makefile b/boot/Makefile index 170fcac8ec4..c2345435201 100644 --- a/boot/Makefile +++ b/boot/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootstd-uclass.o

obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_DISTRO) += bootmeth_distro.o obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_DISTRO_PXE) += bootmeth_pxe.o +obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_EFILOADER) += bootmeth_efi.o

obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o obj-$(CONFIG_$(SPL_TPL_)FIT_SIGNATURE) += fdt_region.o diff --git a/boot/bootmeth_efi.c b/boot/bootmeth_efi.c new file mode 100644 index 00000000000..4c0c3494c3b --- /dev/null +++ b/boot/bootmeth_efi.c @@ -0,0 +1,183 @@ +// 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;
• 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\n", dev_get_uclass_name(media_dev),

•   bflow->fname);
  

• efi_set_bootdev(dev_get_uclass_name(media_dev), 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 = dev_get_uclass_plat(bflow->blk);
• 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);
  

• 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 a .efi file" : "EFI";
  

nits: %s/a/an/

• 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,

+};

Where is the device tree read?

Best regards

Heinrich

+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,

+};