[U-Boot] [PATCH 2/2] eMMC: cmd_mmc.c adds the 'rpmb' sub-command for the 'mmc' command

[Pierre Aubert]

This sub-command adds support for the RPMB partition of an eMMC:
* mmc rpmb key <address of the authentication key>
  Programs the authentication key in the eMMC This key can not
  be overwritten.
* mmc rpmb read <address> <block> <#count> [address of key]
  Reads <#count> blocks of 256 bytes in the RPMB partition
  beginning at block number <block>. If the optionnal
  address of the authentication key is provided, the
  Message Authentication Code (MAC) is verified on each
  block.
* mmc rpmb write <address> <block> <#count> <address of key>
  Writes <#count> blocks of 256 bytes in the RPMB partition
  beginning at block number <block>. The datas are signed
  with the key provided.
* mmc rpmb counter
  Returns the 'Write counter' of the RPMB partition.

The sub-command is conditional on compilation flag CONFIG_SUPPORT_EMMC_RPMB

Signed-off-by: Pierre Aubert <p.aubert at staubli.com>
CC: Pantelis Antoniou <panto at antoniou-consulting.com>
---
 common/cmd_mmc.c |  128 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 127 insertions(+), 1 deletions(-)

diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c
index c1916c9..3cf11e7 100644
--- a/common/cmd_mmc.c
+++ b/common/cmd_mmc.c
@@ -130,7 +130,123 @@ U_BOOT_CMD(
 	"display MMC info",
 	"- display info of the current MMC device"
 );
+#ifdef CONFIG_SUPPORT_EMMC_RPMB
+static int confirm_key_prog(void)
+{
+	puts("Warning: Programming authentication key can be done only once !\n"
+	     "         Use this command only if you are sure of what you are doing,\n"
+	     "Really perform the key programming ? ");
+	if (getc() == 'y') {
+		int c;
+
+		putc('y');
+		c = getc();
+		putc('\n');
+		if (c == '\r')
+			return 1;
+	}
 
+	puts("Authentication key programming aborted\n");
+	return 0;
+}
+static int do_mmcrpmb(int argc, char * const argv[])
+{
+	enum rpmb_state {
+		RPMB_INVALID,
+		RPMB_READ,
+		RPMB_WRITE,
+		RPMB_KEY,
+		RPMB_COUNTER,
+	} state;
+
+	state = RPMB_INVALID;
+	if (argc == 4 && strcmp(argv[2], "key") == 0)
+		state = RPMB_KEY;
+	if ((argc == 6 || argc == 7) && strcmp(argv[2], "read") == 0)
+		state = RPMB_READ;
+	else if (argc == 7 && strcmp(argv[2], "write") == 0)
+		state = RPMB_WRITE;
+	else if (argc == 3 && strcmp(argv[2], "counter") == 0)
+		state = RPMB_COUNTER;
+
+	if (state != RPMB_INVALID) {
+		struct mmc *mmc = find_mmc_device(curr_device);
+		void *key_addr;
+		char original_part;
+		int ret;
+
+		if (!mmc) {
+			printf("no mmc device at slot %x\n", curr_device);
+			return CMD_RET_FAILURE;
+		}
+		mmc_init(mmc);
+		if (IS_SD(mmc)) {
+			printf("It is not a EMMC device\n");
+			return CMD_RET_FAILURE;
+		}
+		/* Switch to the RPMB partition */
+		original_part = mmc->part_num;
+		if (mmc->part_num != MMC_PART_RPMB) {
+			if (mmc_switch_part(curr_device, MMC_PART_RPMB) != 0)
+				return CMD_RET_FAILURE;
+			mmc->part_num = MMC_PART_RPMB;
+		}
+		ret = CMD_RET_SUCCESS;
+		if (state == RPMB_KEY) {
+			key_addr = (void *)simple_strtoul(argv[3], NULL, 16);
+			if (confirm_key_prog()) {
+				if (mmc_rpmb_set_key(mmc, key_addr)) {
+					printf("ERROR - Key already programmed ?\n");
+					ret = CMD_RET_FAILURE;
+				}
+			} else {
+				ret = CMD_RET_FAILURE;
+			}
+		} else if (state == RPMB_COUNTER) {
+			unsigned long counter;
+			if (mmc_rpmb_get_counter(mmc, &counter))
+				ret = CMD_RET_FAILURE;
+			else
+				printf("Write counter= %lx\n", counter);
+		} else {
+			u16 blk, cnt;
+			void *addr;
+			int n;
+
+			addr = (void *)simple_strtoul(argv[3], NULL, 16);
+			blk = simple_strtoul(argv[4], NULL, 16);
+			cnt = simple_strtoul(argv[5], NULL, 16);
+
+			if (state == RPMB_READ) {
+				key_addr = (argc == 7) ?
+					(void *)simple_strtoul(argv[6],
+							       NULL, 16) :
+					NULL;
+				n =  mmc_rpmb_read(mmc, addr, blk, cnt,
+						   key_addr);
+			} else {
+				key_addr = (void *)simple_strtoul(argv[6],
+								  NULL, 16);
+				n =  mmc_rpmb_write(mmc, addr, blk, cnt,
+						    key_addr);
+			}
+			printf("%d RPMB blocks %s: %s\n",
+			       n, argv[2], (n == cnt) ? "OK" : "ERROR");
+			if (n != cnt)
+				ret = CMD_RET_FAILURE;
+		}
+
+		/* Return to orginal partition */
+		if (mmc->part_num != original_part) {
+			if (mmc_switch_part(curr_device, original_part) != 0)
+				return CMD_RET_FAILURE;
+			mmc->part_num = original_part;
+		}
+		return ret;
+	} else
+		return CMD_RET_USAGE;
+}
+#endif
 static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	enum mmc_state state;
@@ -365,6 +481,10 @@ static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 
 		return mmc_set_rst_n_function(mmc, enable);
 #endif /* CONFIG_SUPPORT_EMMC_BOOT */
+#ifdef CONFIG_SUPPORT_EMMC_RPMB
+	} else if (strcmp(argv[1], "rpmb") == 0) {
+		return do_mmcrpmb(argc, argv);
+#endif /*  CONFIG_SUPPORT_EMMC_RPMB */
 	}
 
 	else if (argc == 3 && strcmp(argv[1], "setdsr") == 0) {
@@ -454,7 +574,7 @@ static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 }
 
 U_BOOT_CMD(
-	mmc, 6, 1, do_mmcops,
+	mmc, 7, 1, do_mmcops,
 	"MMC sub system",
 	"read addr blk# cnt\n"
 	"mmc write addr blk# cnt\n"
@@ -474,6 +594,12 @@ U_BOOT_CMD(
 	" - 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"
 #endif
+#ifdef CONFIG_SUPPORT_EMMC_RPMB
+	"mmc rpmb read addr blk# cnt [address of auth-key] - block size is 256 bytes\n"
+	"mmc rpmb write addr blk# cnt <address of auth-key> - block size is 256 bytes\n"
+	"mmc rpmb key <address of auth-key> - program the RPMB authentication key.\n"
+	"mmc rpmb counter - read the value of the write counter\n"
+#endif
 	"mmc setdsr - set DSR register value\n"
 	);
 #endif /* !CONFIG_GENERIC_MMC */
-- 
1.7.6.5