dfu: add 'SCRIPT' entity

Define a new 'SCRIPT' type for DFU entities. The downloaded data are
treated as simple u-boot's scripts and executed with run_command_list()
function.

Flashing the 'SCRIPT' entity might result in changing the 'dfu_alt_info'
environment variable from the flashed script, so add a global variable
for tracking the potential need to reinitialize the dfu_alt_info related
structures.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

doc/README.dfu

@@ -17,7 +17,7 @@ Overview:
   - The access to mediums is done in DFU backends (driver/dfu)
 
   Today the supported DFU backends are:
-  - MMC (RAW or FAT / EXT2 / EXT3 / EXT4 file system / SKIP)
+  - MMC (RAW or FAT / EXT2 / EXT3 / EXT4 file system / SKIP / SCRIPT)
   - NAND
   - RAM
   - SF (serial flash)
@@ -92,6 +92,7 @@ Commands:
       <name> fat <dev> <part_id> [mmcpart <num>]   file in FAT partition
       <name> ext4 <dev> <part_id> [mmcpart <num>]  file in EXT4 partition
       <name> skip 0 0                              ignore flashed data
+      <name> script 0 0                            execute commands in shell
 
       with <partid> being the GPT or DOS partition index,
       with <num> being the eMMC hardware partition number.
@@ -116,6 +117,20 @@ Commands:
 
       "u-boot-<board1>.bin raw 0x80 0x800; u-boot-<board2>.bin skip 0 0"
 
+    When flashing new system image requires do some more complex things
+    than just writing data to the storage medium, one can use 'script'
+    type. Data written to such entity will be executed as a command list
+    in the u-boot's shell. This for example allows to re-create partition
+    layout and even set new dfu_alt_info for the newly created paritions.
+    Such script would look like:
+	--->8---
+	setenv dfu_alt_info ...
+	setenv mbr_parts ...
+	mbr write ...
+	--->8---
+    Please note that this means that user will be able to execute any
+    arbitrary commands just like in the u-boot's shell.
+
   "nand" (raw slc nand device)
     cmd: dfu 0 nand <dev>
     each element in "dfu_alt_info" =

drivers/dfu/dfu.c

@@ -26,6 +26,8 @@ static struct hash_algo *dfu_hash_algo;
 static unsigned long dfu_timeout = 0;
 #endif
 
+bool dfu_reinit_needed = false;
+
 /*
  * The purpose of the dfu_flush_callback() function is to
  * provide callback for dfu user
@@ -139,6 +141,8 @@ int dfu_init_env_entities(char *interface, char *devstr)
 	char *env_bkp;
 	int ret = 0;
 
+	dfu_reinit_needed = false;
+
 #ifdef CONFIG_SET_DFU_ALT_INFO
 	set_dfu_alt_info(interface, devstr);
 #endif
@@ -614,7 +618,8 @@ const char *dfu_get_dev_type(enum dfu_device_type t)
 const char *dfu_get_layout(enum dfu_layout l)
 {
 	const char *const dfu_layout[] = {NULL, "RAW_ADDR", "FAT", "EXT2",
-					  "EXT3", "EXT4", "RAM_ADDR", "SKIP" };
+					  "EXT3", "EXT4", "RAM_ADDR", "SKIP",
+					  "SCRIPT" };
 	return dfu_layout[l];
 }
 

drivers/dfu/dfu_mmc.c

@@ -16,6 +16,7 @@
 #include <fat.h>
 #include <mmc.h>
 #include <part.h>
+#include <command.h>
 
 static unsigned char *dfu_file_buf;
 static u64 dfu_file_buf_len;
@@ -206,6 +207,9 @@ int dfu_write_medium_mmc(struct dfu_entity *dfu,
 	case DFU_FS_EXT4:
 		ret = mmc_file_buf_write(dfu, offset, buf, len);
 		break;
+	case DFU_SCRIPT:
+		ret = run_command_list(buf, *len, 0);
+		break;
 	case DFU_SKIP:
 		ret = 0;
 		break;
@@ -221,9 +225,21 @@ int dfu_flush_medium_mmc(struct dfu_entity *dfu)
 {
 	int ret = 0;
 
-	if (dfu->layout != DFU_RAW_ADDR) {
+	switch (dfu->layout) {
-		/* Do stuff here. */
+	case DFU_FS_FAT:
+	case DFU_FS_EXT4:
 		ret = mmc_file_buf_write_finish(dfu);
+		break;
+	case DFU_SCRIPT:
+		/* script may have changed the dfu_alt_info */
+		dfu_reinit_needed = true;
+		break;
+	case DFU_RAW_ADDR:
+	case DFU_SKIP:
+		break;
+	default:
+		printf("%s: Layout (%s) not (yet) supported!\n", __func__,
+		       dfu_get_layout(dfu->layout));
 	}
 
 	return ret;
@@ -243,6 +259,7 @@ int dfu_get_medium_size_mmc(struct dfu_entity *dfu, u64 *size)
 		if (ret < 0)
 			return ret;
 		return 0;
+	case DFU_SCRIPT:
 	case DFU_SKIP:
 		return 0;
 	default:
@@ -408,6 +425,8 @@ int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr, char *s)
 		dfu->layout = DFU_FS_EXT4;
 	} else if (!strcmp(entity_type, "skip")) {
 		dfu->layout = DFU_SKIP;
+	} else if (!strcmp(entity_type, "script")) {
+		dfu->layout = DFU_SCRIPT;
 	} else {
 		pr_err("Memory layout (%s) not supported!\n", entity_type);
 		return -ENODEV;

include/dfu.h

@@ -34,6 +34,7 @@ enum dfu_layout {
 	DFU_FS_EXT4,
 	DFU_RAM_ADDR,
 	DFU_SKIP,
+	DFU_SCRIPT,
 };
 
 enum dfu_op {
@@ -497,6 +498,8 @@ static inline int dfu_fill_entity_virt(struct dfu_entity *dfu, char *devstr,
 }
 #endif
 
+extern bool dfu_reinit_needed;
+
 #if CONFIG_IS_ENABLED(DFU_WRITE_ALT)
 /**
  * dfu_write_by_name() - write data to DFU medium