cmd: bootm: add a stage pre-load

Add a stage pre-load to the command bootm.
Right now, this stage may be used to read a
header and check the signature of the full
image.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
diff --git a/boot/bootm.c b/boot/bootm.c
index 00c00ae..714406a 100644
--- a/boot/bootm.c
+++ b/boot/bootm.c
@@ -87,6 +87,33 @@
 	return 0;
 }
 
+static ulong bootm_data_addr(int argc, char *const argv[])
+{
+	ulong addr;
+
+	if (argc > 0)
+		addr = simple_strtoul(argv[0], NULL, 16);
+	else
+		addr = image_load_addr;
+
+	return addr;
+}
+
+static int bootm_pre_load(struct cmd_tbl *cmdtp, int flag, int argc,
+			  char *const argv[])
+{
+	ulong data_addr = bootm_data_addr(argc, argv);
+	int ret = 0;
+
+	if (CONFIG_IS_ENABLED(CMD_BOOTM_PRE_LOAD))
+		ret = image_pre_load(data_addr);
+
+	if (ret)
+		ret = CMD_RET_FAILURE;
+
+	return ret;
+}
+
 static int bootm_find_os(struct cmd_tbl *cmdtp, int flag, int argc,
 			 char *const argv[])
 {
@@ -677,6 +704,9 @@
 	if (states & BOOTM_STATE_START)
 		ret = bootm_start(cmdtp, flag, argc, argv);
 
+	if (!ret && (states & BOOTM_STATE_PRE_LOAD))
+		ret = bootm_pre_load(cmdtp, flag, argc, argv);
+
 	if (!ret && (states & BOOTM_STATE_FINDOS))
 		ret = bootm_find_os(cmdtp, flag, argc, argv);
 
@@ -866,6 +896,9 @@
 					      &fit_uname_config,
 					      &fit_uname_kernel);
 
+	if (CONFIG_IS_ENABLED(CMD_BOOTM_PRE_LOAD))
+		img_addr += image_load_offset;
+
 	bootstage_mark(BOOTSTAGE_ID_CHECK_MAGIC);
 
 	/* check image type, for FIT images get FIT kernel node */
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 1d84012..7bd9546 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -194,6 +194,16 @@
 	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 e8b7066..87d40d4 100644
--- a/cmd/bootm.c
+++ b/cmd/bootm.c
@@ -70,7 +70,8 @@
 	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;
 	} else {
 		/* Unrecognized command */
 		return CMD_RET_USAGE;
@@ -126,7 +127,7 @@
 	}
 
 	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 |
diff --git a/include/image.h b/include/image.h
index fbcf70f..496b7af 100644
--- a/include/image.h
+++ b/include/image.h
@@ -351,6 +351,7 @@
 #define	BOOTM_STATE_OS_PREP	(0x00000100)
 #define	BOOTM_STATE_OS_FAKE_GO	(0x00000200)	/* 'Almost' run the OS */
 #define	BOOTM_STATE_OS_GO	(0x00000400)
+#define	BOOTM_STATE_PRE_LOAD	0x00000800
 	int		state;
 
 #if defined(CONFIG_LMB) && !defined(USE_HOSTCC)