[PATCH v2] mmc: Update environment variable with active partition

[Reuben Dowle <reubendowle0@gmail.com>]

This patch allows uboot scripts make choices about where to boot from based
on the active mmc boot partition. This allows having two copies of kernel,
filesystems etc, and choosing which to boot from based off of the active
bootloader partition.

Signed-off-by: Reuben Dowle <reuben.dowle@4rf.com>
---
 cmd/mmc.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/cmd/mmc.c b/cmd/mmc.c
index a10f137..afa8e7b 100644
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -808,7 +808,7 @@ static int do_mmc_boot_resize(struct cmd_tbl *cmdtp, int flag,
 	return CMD_RET_SUCCESS;
 }
 
-static int mmc_partconf_print(struct mmc *mmc)
+static int mmc_partconf_print(struct mmc *mmc, const char *varname)
 {
 	u8 ack, access, part;
 
@@ -821,6 +821,9 @@ static int mmc_partconf_print(struct mmc *mmc)
 	ack = EXT_CSD_EXTRACT_BOOT_ACK(mmc->part_config);
 	part = EXT_CSD_EXTRACT_BOOT_PART(mmc->part_config);
 
+	if(varname)
+		env_set_hex(varname, part);
+
 	printf("EXT_CSD[179], PARTITION_CONFIG:\n"
 		"BOOT_ACK: 0x%x\n"
 		"BOOT_PARTITION_ENABLE: 0x%x\n"
@@ -836,7 +839,7 @@ static int do_mmc_partconf(struct cmd_tbl *cmdtp, int flag,
 	struct mmc *mmc;
 	u8 ack, part_num, access;
 
-	if (argc != 2 && argc != 5)
+	if (argc != 2 && argc != 3 && argc != 5)
 		return CMD_RET_USAGE;
 
 	dev = simple_strtoul(argv[1], NULL, 10);
@@ -850,8 +853,8 @@ static int do_mmc_partconf(struct cmd_tbl *cmdtp, int flag,
 		return CMD_RET_FAILURE;
 	}
 
-	if (argc == 2)
-		return mmc_partconf_print(mmc);
+	if (argc == 2 || argc == 3)
+		return mmc_partconf_print(mmc, argc == 3 ? argv[2] : NULL);
 
 	ack = simple_strtoul(argv[2], NULL, 10);
 	part_num = simple_strtoul(argv[3], NULL, 10);
@@ -1061,8 +1064,11 @@ U_BOOT_CMD(
 	" - Set the BOOT_BUS_WIDTH field of the specified device\n"
 	"mmc bootpart-resize <dev> <boot part size MB> <RPMB part size MB>\n"
 	" - Change sizes of boot and RPMB partitions of specified device\n"
-	"mmc partconf <dev> [boot_ack boot_partition partition_access]\n"
-	" - Show or change the bits of the PARTITION_CONFIG field of the specified device\n"
+	"mmc partconf <dev> [varname]\n"
+	" - Show the bits of the PARTITION_CONFIG field of the specified device,\n"
+	"   optionally storing the boot_partion value into <varname>"
+	"mmc partconf <dev> <boot_ack> <boot_partition> <partition_access>\n"
+	" - Change the bits of the PARTITION_CONFIG field of the specified device\n"
 	"mmc rst-function <dev> <value>\n"
 	" - Change the RST_n_FUNCTION field of the specified device\n"
 	"   WARNING: This is a write-once field and 0 / 1 / 2 are the only valid values.\n"
-- 
2.7.4