[PATCH 1/2] ARM: AM33xx: swap MLO SPI image automatically

[Sascha Hauer]

The MLO image for SPI differs in the normal MLO in that the
SPI version is big endian. As both types of images are floating
around detect whether or not the image is swapped automatically.
This also adds a check whether we have a valid MLO image.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 arch/arm/mach-omap/am33xx_bbu_spi_mlo.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap/am33xx_bbu_spi_mlo.c b/arch/arm/mach-omap/am33xx_bbu_spi_mlo.c
index ff9f8a6..1aa3d7b 100644
--- a/arch/arm/mach-omap/am33xx_bbu_spi_mlo.c
+++ b/arch/arm/mach-omap/am33xx_bbu_spi_mlo.c
@@ -32,6 +32,18 @@ static int spi_nor_mlo_handler(struct bbu_handler *handler,
 	uint32_t readbuf;
 	int size = data->len;
 	void *image = data->image;
+	uint32_t *header;
+	int swap = 0;
+
+	header = data->image;
+	if (header[5] == 0x43485345) {
+		swap = 0;
+	} else if (header[5] == 0x45534843) {
+		swap = 1;
+	} else {
+		if (!bbu_force(data, "Not a MLO image"))
+			return -EINVAL;
+	}
 
 	dstfd = open(data->devicefile, O_WRONLY);
 	if (dstfd < 0) {
@@ -49,7 +61,8 @@ static int spi_nor_mlo_handler(struct bbu_handler *handler,
 	for (; size >= 0; size -= 4) {
 		memcpy((char *)&readbuf, image, 4);
 
-		readbuf = cpu_to_be32(readbuf);
+		if (swap)
+			readbuf = cpu_to_be32(readbuf);
 		ret = write(dstfd, &readbuf, 4);
 		if (ret < 0) {
 			perror("write");
-- 
2.0.0.rc0