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>

diff --git a/boot/Kconfig b/boot/Kconfig
index 9e02a7549af7f22ddd7ac988a3a15c96c2e5d372..0bfea2791da472570b3583f716a7a9bd51848386 100644 (file)
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -349,6 +349,27 @@ 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 9c9613d22a1f7759db6ab19c0cb724d938e7f521..4f9267687fa834af6c8300727dc2afc4777ac28f 100644 (file)
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -26,6 +26,7 @@ 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 (file)
index 0000000..d5438eb
--- /dev/null
+++ b/boot/bootmeth_efi.c
@@ -0,0 +1,188 @@
+// 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,
+};