arm: imx: hab: Fix authenticate_image result code

authenticate_image returns 1 for success and 0 for failure. That result
code is mapped directly to the result code for the command line function
hab_auth_img - which means when hab_auth_img succeeds it is returning
CMD_RET_FAILURE (1) instead of CMD_RET_SUCCESS (0).

This patch fixes this behaviour by making authenticate_image() return 0 for
success and 1 for failure. Both users of authenticate_image() as a result
have some minimal churn. The upshot is once done when hab_auth_img is
called from the command line we set $? in the standard way for scripting
functions to act on.

Fixes: 36c1ca4d46ef ("imx: Support i.MX6 High Assurance Boot
authentication")

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Sven Ebenfeld <sven.ebenfeld@gmail.com>
Cc: George McCollister <george.mccollister@gmail.com>
Cc: Breno Matheus Lima <brenomatheus@gmail.com>
Tested-by: Breno Lima <breno.lima@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>

arch/arm/mach-imx/hab.c

@@ -373,7 +373,10 @@ static int do_authenticate_image(cmd_tbl_t *cmdtp, int flag, int argc,
 	ivt_offset = simple_strtoul(argv[2], NULL, 16);
 
 	rcode = authenticate_image(addr, ivt_offset);
-
+	if (rcode == 0)
+		rcode = CMD_RET_SUCCESS;
+	else
+		rcode = CMD_RET_FAILURE;
 	return rcode;
 }
 
@@ -415,7 +418,7 @@ int authenticate_image(uint32_t ddr_start, uint32_t image_size)
 	uint32_t load_addr = 0;
 	size_t bytes;
 	ptrdiff_t ivt_offset = 0;
-	int result = 0;
+	int result = 1;
 	ulong start;
 	hab_rvt_authenticate_image_t *hab_rvt_authenticate_image;
 	hab_rvt_entry_t *hab_rvt_entry;
@@ -510,7 +513,7 @@ int authenticate_image(uint32_t ddr_start, uint32_t image_size)
 	}
 
 	if ((!is_hab_enabled()) || (load_addr != 0))
-		result = 1;
+		result = 0;
 
 	return result;
 }

arch/arm/mach-imx/spl.c

@@ -166,8 +166,8 @@ __weak void __noreturn jump_to_image_no_args(struct spl_image_info *spl_image)
 
 	/* HAB looks for the CSF at the end of the authenticated data therefore,
 	 * we need to subtract the size of the CSF from the actual filesize */
-	if (authenticate_image(spl_image->load_addr,
-			       spl_image->size - CONFIG_CSF_SIZE)) {
+	if (!authenticate_image(spl_image->load_addr,
+				spl_image->size - CONFIG_CSF_SIZE)) {
 		image_entry();
 	} else {
 		puts("spl: ERROR:  image authentication unsuccessful\n");