Merge branch '2022-03-31-image-add-a-stage-pre-load' into next

To quote the author:
This series adds a stage pre-load before launching an image.  This stage
is used to read a header before the image and this header contains the
signature of the full image.  So u-boot may check the full image before
using any data of the image.

The support of this header is added to binman, and a command verify
checks the signature of a blob and set the u-boot env variable
"loadaddr_verified" to the beginning of the "real" image.

The support of this header is only added to binman, but it may also be
added to mkimage.

2 files changed, 43 insertions, 2 deletions

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 1d8401236fb..7bd95466131 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -194,6 +194,16 @@ config CMD_BOOTM
 	help
 	  Boot an application image from the memory.
 
+config CMD_BOOTM_PRE_LOAD
+       bool "enable pre-load on bootm"
+       depends on CMD_BOOTM
+       depends on IMAGE_PRE_LOAD
+       default n
+       help
+         Enable support of stage pre-load for the bootm command.
+	 This stage allow to check or modify the image provided
+	 to the bootm command.
+
 config BOOTM_EFI
 	bool "Support booting UEFI FIT images"
 	depends on CMD_BOOTEFI && CMD_BOOTM && FIT
diff --git a/cmd/bootm.c b/cmd/bootm.c
index e8b70668882..1f70ee9e911 100644
--- a/cmd/bootm.c
+++ b/cmd/bootm.c
@@ -44,6 +44,9 @@ static int do_imls(struct cmd_tbl *cmdtp, int flag, int argc,
 static struct cmd_tbl cmd_bootm_sub[] = {
 	U_BOOT_CMD_MKENT(start, 0, 1, (void *)BOOTM_STATE_START, "", ""),
 	U_BOOT_CMD_MKENT(loados, 0, 1, (void *)BOOTM_STATE_LOADOS, "", ""),
+#ifdef CONFIG_CMD_BOOTM_PRE_LOAD
+	U_BOOT_CMD_MKENT(preload, 0, 1, (void *)BOOTM_STATE_PRE_LOAD, "", ""),
+#endif
 #ifdef CONFIG_SYS_BOOT_RAMDISK_HIGH
 	U_BOOT_CMD_MKENT(ramdisk, 0, 1, (void *)BOOTM_STATE_RAMDISK, "", ""),
 #endif
@@ -57,6 +60,20 @@ static struct cmd_tbl cmd_bootm_sub[] = {
 	U_BOOT_CMD_MKENT(go, 0, 1, (void *)BOOTM_STATE_OS_GO, "", ""),
 };
 
+#if defined(CONFIG_CMD_BOOTM_PRE_LOAD)
+static ulong bootm_get_addr(int argc, char *const argv[])
+{
+	ulong addr;
+
+	if (argc > 0)
+		addr = hextoul(argv[0], NULL);
+	else
+		addr = image_load_addr;
+
+	return addr;
+}
+#endif
+
 static int do_bootm_subcommand(struct cmd_tbl *cmdtp, int flag, int argc,
 			       char *const argv[])
 {
@@ -70,7 +87,12 @@ static int do_bootm_subcommand(struct cmd_tbl *cmdtp, int flag, int argc,
 	if (c) {
 		state = (long)c->cmd;
 		if (state == BOOTM_STATE_START)
-			state |= BOOTM_STATE_FINDOS | BOOTM_STATE_FINDOTHER;
+			state |= BOOTM_STATE_PRE_LOAD | BOOTM_STATE_FINDOS |
+				 BOOTM_STATE_FINDOTHER;
+#if defined(CONFIG_CMD_BOOTM_PRE_LOAD)
+		if (state == BOOTM_STATE_PRE_LOAD)
+			state |= BOOTM_STATE_START;
+#endif
 	} else {
 		/* Unrecognized command */
 		return CMD_RET_USAGE;
@@ -84,6 +106,12 @@ static int do_bootm_subcommand(struct cmd_tbl *cmdtp, int flag, int argc,
 
 	ret = do_bootm_states(cmdtp, flag, argc, argv, state, &images, 0);
 
+#if defined(CONFIG_CMD_BOOTM_PRE_LOAD)
+	if (!ret && (state & BOOTM_STATE_PRE_LOAD))
+		env_set_hex("loadaddr_verified",
+			    bootm_get_addr(argc, argv) + image_load_offset);
+#endif
+
 	return ret;
 }
 
@@ -126,7 +154,7 @@ int do_bootm(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	}
 
 	return do_bootm_states(cmdtp, flag, argc, argv, BOOTM_STATE_START |
-		BOOTM_STATE_FINDOS | BOOTM_STATE_FINDOTHER |
+		BOOTM_STATE_FINDOS | BOOTM_STATE_PRE_LOAD | BOOTM_STATE_FINDOTHER |
 		BOOTM_STATE_LOADOS |
 #ifdef CONFIG_SYS_BOOT_RAMDISK_HIGH
 		BOOTM_STATE_RAMDISK |
@@ -176,6 +204,9 @@ static char bootm_help_text[] =
 	"must be\n"
 	"issued in the order below (it's ok to not issue all sub-commands):\n"
 	"\tstart [addr [arg ...]]\n"
+#if defined(CONFIG_CMD_BOOTM_PRE_LOAD)
+	"\tpreload [addr [arg ..]] - run only the preload stage\n"
+#endif
 	"\tloados  - load OS image\n"
 #if defined(CONFIG_SYS_BOOT_RAMDISK_HIGH)
 	"\tramdisk - relocate initrd, set env initrd_start/initrd_end\n"