bootstd: Add an implementation of EFI bootmgr

Add a bootmeth driver which handles EFI boot manager, using EFI_LOADER.

In effect, this provides the same functionality as the 'bootefi bootmgr'
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.

Signed-off-by: Simon Glass <sjg@chromium.org>

2 files changed, 89 insertions, 0 deletions

diff --git a/boot/Makefile b/boot/Makefile
index 7325dbc1dd..fe221d7f44 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -27,6 +27,9 @@ 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
+ifdef CONFIG_$(SPL_TPL_)BOOTSTD_FULL
+obj-$(CONFIG_$(SPL_TPL_)CMD_BOOTEFI_BOOTMGR) += bootmeth_efi_mgr.o
+endif
 
 obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o
 obj-$(CONFIG_$(SPL_TPL_)FIT_SIGNATURE) += fdt_region.o
diff --git a/boot/bootmeth_efi_mgr.c b/boot/bootmeth_efi_mgr.c
new file mode 100644
index 0000000000..a6914466db
--- /dev/null
+++ b/boot/bootmeth_efi_mgr.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Bootmethod for EFI boot manager
+ *
+ * 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>
+
+static int efi_mgr_check(struct udevice *dev, struct bootflow_iter *iter)
+{
+	int ret;
+
+	/* Must be an bootstd device */
+	ret = bootflow_iter_uses_system(iter);
+	if (ret)
+		return log_msg_ret("net", ret);
+
+	return 0;
+}
+
+static int efi_mgr_read_bootflow(struct udevice *dev, struct bootflow *bflow)
+{
+	/*
+	 * Just assume there is something to boot since we don't have any way
+	 * of knowing in advance
+	 */
+	bflow->state = BOOTFLOWST_READY;
+
+	return 0;
+}
+
+static int efi_mgr_read_file(struct udevice *dev, struct bootflow *bflow,
+				const char *file_path, ulong addr, ulong *sizep)
+{
+	/* Files are loaded by the 'bootefi bootmgr' command */
+
+	return -ENOSYS;
+}
+
+static int efi_mgr_boot(struct udevice *dev, struct bootflow *bflow)
+{
+	int ret;
+
+	/* Booting is handled by the 'bootefi bootmgr' command */
+	ret = run_command("bootefi bootmgr", 0);
+
+	return 0;
+}
+
+static int bootmeth_efi_mgr_bind(struct udevice *dev)
+{
+	struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
+
+	plat->desc = "EFI bootmgr flow";
+
+	return 0;
+}
+
+static struct bootmeth_ops efi_mgr_bootmeth_ops = {
+	.check		= efi_mgr_check,
+	.read_bootflow	= efi_mgr_read_bootflow,
+	.read_file	= efi_mgr_read_file,
+	.boot		= efi_mgr_boot,
+};
+
+static const struct udevice_id efi_mgr_bootmeth_ids[] = {
+	{ .compatible = "u-boot,efi-bootmgr" },
+	{ }
+};
+
+U_BOOT_DRIVER(bootmeth_zefi_mgr) = {
+	.name		= "bootmeth_efi_mgr",
+	.id		= UCLASS_BOOTMETH,
+	.of_match	= efi_mgr_bootmeth_ids,
+	.ops		= &efi_mgr_bootmeth_ops,
+	.bind		= bootmeth_efi_mgr_bind,
+};