xload: get barebox size from barebox_arm_head

Add functions to read the barebox_arm_head, check barebox magicword
and read out the barebox image size.
Create a inital partion of 1Mb to access the barebox image on nand.

Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-omap/include/mach/xload.h

@@ -1,7 +1,7 @@
 #ifndef _MACH_XLOAD_H
 #define _MACH_XLOAD_H
 
-void *omap_xload_boot_nand(int offset, int size);
+void *omap_xload_boot_nand(int offset);
 void *omap_xload_boot_mmc(void);
 
 enum omap_boot_src {

arch/arm/mach-omap/xload.c

@@ -7,16 +7,65 @@
 #include <fcntl.h>
 #include <mach/xload.h>
 #include <sizes.h>
+#include <filetype.h>
 
-void *omap_xload_boot_nand(int offset, int size)
+void *read_image_head(const char *name)
+{
+	void *header = xmalloc(ARM_HEAD_SIZE);
+	struct cdev *cdev;
+	int ret;
+
+	cdev = cdev_open(name, O_RDONLY);
+	if (!cdev) {
+		printf("failed to open partition\n");
+		return NULL;
+	}
+
+	ret = cdev_read(cdev, header, ARM_HEAD_SIZE, 0, 0);
+	cdev_close(cdev);
+
+	if (ret != ARM_HEAD_SIZE) {
+		printf("failed to read from partition\n");
+		return NULL;
+	}
+
+	return header;
+}
+
+unsigned int get_image_size(void *head)
+{
+	unsigned int ret = 0;
+	unsigned int *psize = head + ARM_HEAD_SIZE_OFFSET;
+
+	if (is_barebox_arm_head(head))
+		ret = *psize;
+	debug("Detected barebox image size %u\n", ret);
+
+	return ret;
+}
+
+void *omap_xload_boot_nand(int offset)
 {
 	int ret;
-	void *to = xmalloc(size);
+	int size;
+	void *to, *header;
 	struct cdev *cdev;
 
-	devfs_add_partition("nand0", offset, size, DEVFS_PARTITION_FIXED, "x");
+	devfs_add_partition("nand0", offset, SZ_1M, DEVFS_PARTITION_FIXED, "x");
 	dev_add_bb_dev("x", "bbx");
 
+	header = read_image_head("bbx");
+	if (header == NULL)
+		return NULL;
+
+	size = get_image_size(header);
+	if (!size) {
+		printf("failed to get image size\n");
+		return NULL;
+	}
+
+	to = xmalloc(size);
+
 	cdev = cdev_open("bbx", O_RDONLY);
 	if (!cdev) {
 		printf("failed to open nand\n");
@@ -80,7 +129,7 @@ int run_shell(void)
 		printf("unknown boot source. Fall back to nand\n");
 	case OMAP_BOOTSRC_NAND:
 		printf("booting from NAND\n");
-		func = omap_xload_boot_nand(SZ_128K, SZ_256K);
+		func = omap_xload_boot_nand(SZ_128K);
 		break;
 	}
 

common/filetype.c

@@ -75,7 +75,7 @@ enum filetype file_detect_type(void *_buf)
 
 	if (strncmp(buf8, "#!/bin/sh", 9) == 0)
 		return filetype_sh;
-	if (buf[8] == 0x65726162 && buf[9] == 0x00786f62)
+	if (is_barebox_arm_head(_buf))
 		return filetype_arm_barebox;
 	if (buf[9] == 0x016f2818 || buf[9] == 0x18286f01)
 		return filetype_arm_zimage;

include/filetype.h

@@ -25,4 +25,20 @@ const char *file_type_to_string(enum filetype f);
 enum filetype file_detect_type(void *_buf);
 enum filetype file_name_detect_type(const char *filename);
 
+#define ARM_HEAD_SIZE			0x30
+#define ARM_HEAD_MAGICWORD_OFFSET	0x20
+#define ARM_HEAD_SIZE_OFFSET		0x2C
+
+#ifdef CONFIG_ARM
+static inline int is_barebox_arm_head(const char *head)
+{
+	return !strcmp(head + ARM_HEAD_MAGICWORD_OFFSET, "barebox");
+}
+#else
+static inline int is_barebox_arm_head(const char *head)
+{
+	return 0;
+}
+#endif
+
 #endif /* __FILE_TYPE_H */