efi_loader: Add "bootefi" command

In order to execute an EFI application, we need to bridge the gap between
U-Boot's notion of executing images and EFI's notion of doing the same.

The best path forward IMHO here is to stick completely to the way U-Boot
deals with payloads. You manually load them using whatever method to RAM
and then have a simple boot command to execute them. So in our case, you
would do

  # load mmc 0:1 $loadaddr grub.efi
  # bootefi $loadaddr

which then gets you into a grub shell. Fdt information known to U-boot
via the fdt addr command is also passed to the EFI payload.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
[trini: Guard help text with CONFIG_SYS_LONGHELP]
Signed-off-by: Tom Rini <trini@konsulko.com>

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 2ed0263a41340b6a7d271ce6e269f04070659a45..7cdff04a624b0448186a743303010bfaa3ae42f0 100644 (file)
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -148,6 +148,13 @@ config CMD_BOOTM
        help
          Boot an application image from the memory.
 
+config CMD_BOOTEFI
+       bool "bootefi"
+       depends on EFI_LOADER
+       default y
+       help
+         Boot an EFI image from memory.
+
 config CMD_ELF
        bool "bootelf, bootvx"
        default y

diff --git a/cmd/Makefile b/cmd/Makefile
index 03f7e0a21d2f469319fcb08d4a3180156ca94289..76046218595b5e2f2c32d589e6c834607bcd984e 100644 (file)
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_CMD_SOURCE) += source.o
 obj-$(CONFIG_CMD_BDI) += bdinfo.o
 obj-$(CONFIG_CMD_BEDBUG) += bedbug.o
 obj-$(CONFIG_CMD_BMP) += bmp.o
+obj-$(CONFIG_CMD_BOOTEFI) += bootefi.o
 obj-$(CONFIG_CMD_BOOTMENU) += bootmenu.o
 obj-$(CONFIG_CMD_BOOTLDR) += bootldr.o
 obj-$(CONFIG_CMD_BOOTSTAGE) += bootstage.o

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
new file mode 100644 (file)
index 0000000..98d1fca
--- /dev/null
+++ b/cmd/bootefi.c
@@ -0,0 +1,182 @@
+/*
+ *  EFI application loader
+ *
+ *  Copyright (c) 2016 Alexander Graf
+ *
+ *  SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <efi_loader.h>
+#include <errno.h>
+#include <libfdt.h>
+#include <libfdt_env.h>
+
+/*
+ * When booting using the "bootefi" command, we don't know which
+ * physical device the file came from. So we create a pseudo-device
+ * called "bootefi" with the device path /bootefi.
+ *
+ * In addition to the originating device we also declare the file path
+ * of "bootefi" based loads to be /bootefi.
+ */
+static struct efi_device_path_file_path bootefi_dummy_path[] = {
+       {
+               .dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE,
+               .dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH,
+               .dp.length = sizeof(bootefi_dummy_path[0]),
+               .str = { 'b','o','o','t','e','f','i' },
+       }, {
+               .dp.type = DEVICE_PATH_TYPE_END,
+               .dp.sub_type = DEVICE_PATH_SUB_TYPE_END,
+               .dp.length = sizeof(bootefi_dummy_path[0]),
+       }
+};
+
+static efi_status_t bootefi_open_dp(void *handle, efi_guid_t *protocol,
+                       void **protocol_interface, void *agent_handle,
+                       void *controller_handle, uint32_t attributes)
+{
+       *protocol_interface = bootefi_dummy_path;
+       return EFI_SUCCESS;
+}
+
+/* The EFI loaded_image interface for the image executed via "bootefi" */
+static struct efi_loaded_image loaded_image_info = {
+       .device_handle = bootefi_dummy_path,
+       .file_path = bootefi_dummy_path,
+};
+
+/* The EFI object struct for the image executed via "bootefi" */
+static struct efi_object loaded_image_info_obj = {
+       .handle = &loaded_image_info,
+       .protocols = {
+               {
+                       /*
+                        * When asking for the loaded_image interface, just
+                        * return handle which points to loaded_image_info
+                        */
+                       .guid = &efi_guid_loaded_image,
+                       .open = &efi_return_handle,
+               },
+               {
+                       /*
+                        * When asking for the device path interface, return
+                        * bootefi_dummy_path
+                        */
+                       .guid = &efi_guid_device_path,
+                       .open = &bootefi_open_dp,
+               },
+       },
+};
+
+/* The EFI object struct for the device the "bootefi" image was loaded from */
+static struct efi_object bootefi_device_obj = {
+       .handle = bootefi_dummy_path,
+       .protocols = {
+               {
+                       /* When asking for the device path interface, return
+                        * bootefi_dummy_path */
+                       .guid = &efi_guid_device_path,
+                       .open = &bootefi_open_dp,
+               }
+       },
+};
+
+/*
+ * Load an EFI payload into a newly allocated piece of memory, register all
+ * EFI objects it would want to access and jump to it.
+ */
+static unsigned long do_bootefi_exec(void *efi)
+{
+       ulong (*entry)(void *image_handle, struct efi_system_table *st);
+       ulong fdt_pages, fdt_size, fdt_start, fdt_end;
+
+       /*
+        * gd lives in a fixed register which may get clobbered while we execute
+        * the payload. So save it here and restore it on every callback entry
+        */
+       efi_save_gd();
+
+       /* Update system table to point to our currently loaded FDT */
+
+       if (working_fdt) {
+               systab.tables[0].guid = EFI_FDT_GUID;
+               systab.tables[0].table = working_fdt;
+               systab.nr_tables = 1;
+
+               /* And reserve the space in the memory map */
+               fdt_start = ((ulong)working_fdt) & ~EFI_PAGE_MASK;
+               fdt_end = ((ulong)working_fdt) + fdt_totalsize(working_fdt);
+               fdt_size = (fdt_end - fdt_start) + EFI_PAGE_MASK;
+               fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
+               /* Give a bootloader the chance to modify the device tree */
+               fdt_pages += 2;
+               efi_add_memory_map(fdt_start, fdt_pages,
+                                  EFI_BOOT_SERVICES_DATA, true);
+
+       } else {
+               printf("WARNING: No device tree loaded, expect boot to fail\n");
+               systab.nr_tables = 0;
+       }
+
+       /* Load the EFI payload */
+       entry = efi_load_pe(efi, &loaded_image_info);
+       if (!entry)
+               return -ENOENT;
+
+       /* Initialize and populate EFI object list */
+       INIT_LIST_HEAD(&efi_obj_list);
+       list_add_tail(&loaded_image_info_obj.link, &efi_obj_list);
+       list_add_tail(&bootefi_device_obj.link, &efi_obj_list);
+#ifdef CONFIG_PARTITIONS
+       efi_disk_register();
+#endif
+
+       /* Call our payload! */
+#ifdef DEBUG_EFI
+       printf("%s:%d Jumping to 0x%lx\n", __func__, __LINE__, (long)entry);
+#endif
+       return entry(&loaded_image_info, &systab);
+}
+
+
+/* Interpreter command to boot an arbitrary EFI image from memory */
+static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+       char *saddr;
+       unsigned long addr;
+       int r = 0;
+
+       if (argc < 2)
+               return 1;
+       saddr = argv[1];
+
+       addr = simple_strtoul(saddr, NULL, 16);
+
+       printf("## Starting EFI application at 0x%08lx ...\n", addr);
+       r = do_bootefi_exec((void *)addr);
+       printf("## Application terminated, r = %d\n", r);
+
+       if (r != 0)
+               r = 1;
+
+       return r;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char bootefi_help_text[] =
+       "<image address>\n"
+       "  - boot EFI payload stored at address <image address>\n"
+       "\n"
+       "Since most EFI payloads want to have a device tree provided, please\n"
+       "make sure you load a device tree using the fdt addr command before\n"
+       "executing bootefi.\n";
+#endif
+
+U_BOOT_CMD(
+       bootefi, 2, 0, do_bootefi,
+       "Boots an EFI payload from memory\n",
+       bootefi_help_text
+);