board: samsung: e850-96: Load LDFW from EFI partition

In case when EFI System Partition is present it can be used to store
firmware binaries, instead of keeping those on separate dedicated
partitions. That simplifies the partition table and makes it more
standard. Rework the firmware loader code to look for LDFW binary at
/EFI/firmware/ldfw.bin on ESP first, and if either the partition or the
file doesn't exist -- fallback to reading it from 'ldfw' partition. This
way backward compatibility can be kept, and Android partition tables
without ESP partition can be handled too.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

1 files changed, 38 insertions, 7 deletions

diff --git a/board/samsung/e850-96/fw.c b/board/samsung/e850-96/fw.c
index 82a0b224c67..8f64e759b43 100644
--- a/board/samsung/e850-96/fw.c
+++ b/board/samsung/e850-96/fw.c
@@ -7,14 +7,16 @@
  */
 
 #include <part.h>
+#include <fs.h>
 #include <linux/arm-smccc.h>
 #include "fw.h"
 
 #define EMMC_IFACE		"mmc"
 #define EMMC_DEV_NUM		0
+#define LDFW_RAW_PART		"ldfw"
+#define LDFW_FAT_PART		"esp"
+#define LDFW_FAT_PATH		"/EFI/firmware/ldfw.bin"
 
-/* LDFW constants */
-#define LDFW_PART_NAME		"ldfw"
 #define LDFW_NWD_ADDR		0x88000000
 #define LDFW_MAGIC		0x10adab1e
 #define SMC_CMD_LOAD_LDFW	-0x500
@@ -36,7 +38,33 @@ struct ldfw_header {
 	char fw_name[16];
 };
 
-static int read_fw(const char *part_name, void *buf)
+/* Load LDFW binary as a file from FAT partition */
+static int read_fw_from_fat(const char *part_name, const char *path, void *buf)
+{
+	char dev_part_str[8];
+	loff_t len_read;
+	int err;
+
+	snprintf(dev_part_str, sizeof(dev_part_str), "%d#%s", EMMC_DEV_NUM,
+		 LDFW_FAT_PART);
+
+	err = fs_set_blk_dev(EMMC_IFACE, dev_part_str, FS_TYPE_FAT);
+	if (err) {
+		debug("%s: Can't set block device\n", __func__);
+		return -ENODEV;
+	}
+
+	err = fs_read(path, (ulong)buf, 0, 0, &len_read);
+	if (err) {
+		debug("%s: Can't read LDFW file\n", __func__);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/* Load LDFW binary from raw partition on block device into RAM buffer */
+static int read_fw_from_raw(const char *part_name, void *buf)
 {
 	struct blk_desc *blk_desc;
 	struct disk_partition part;
@@ -73,10 +101,13 @@ int load_ldfw(void)
 	u64 size = 0;
 	int err, i;
 
-	/* Load LDFW from the block device partition into RAM buffer */
-	err = read_fw(LDFW_PART_NAME, buf);
-	if (err)
-		return err;
+	/* First try to read LDFW from EFI partition, then from the raw one */
+	err = read_fw_from_fat(LDFW_FAT_PART, LDFW_FAT_PATH, buf);
+	if (err) {
+		err = read_fw_from_raw(LDFW_RAW_PART, buf);
+		if (err)
+			return err;
+	}
 
 	/* Validate LDFW by magic number in its header */
 	hdr = buf;