[PATCH v6 7/7] fpga: zynqmp: support loading encrypted bitfiles

[Adrian Fiergolski]

Add supporting new compatible string "u-boot,zynqmp-fpga-enc" to handle
loading encrypted bitfiles.

This feature requires encrypted FSBL,as according to UG1085:
"The CSU automatically locks out the AES key, stored in either BBRAM or eFUSEs,
 as a key source to the AES engine if the FSBL is not encrypted. This prevents
 using the BBRAM or eFUSE as the key source to the AES engine during run-time
 applications."

Signed-off-and-tested-by: Adrian Fiergolski <adrian.fiergolski at fastree3d.com>
---
 doc/uImage.FIT/source_file_format.txt |  2 ++
 drivers/fpga/zynqmppl.c               | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/doc/uImage.FIT/source_file_format.txt b/doc/uImage.FIT/source_file_format.txt
index 461e2af2a8..2cf77ba3e9 100644
--- a/doc/uImage.FIT/source_file_format.txt
+++ b/doc/uImage.FIT/source_file_format.txt
@@ -188,6 +188,8 @@ the '/images' node should have the following layout:
     "u-boot,fpga-legacy" - the generic fpga loading routine.
     "u-boot,zynqmp-fpga-ddrauth" - signed non-encrypted FPGA bitstream for
     Xilinx Zynq UltraScale+ (ZymqMP) device.
+    "u-boot,zynqmp-fpga-enc" - encrypted FPGA bitstream for Xilinx Zynq
+    UltraScale+ (ZymqMP) device.
 
   Optional nodes:
   - hash-1 : Each hash sub-node represents separate hash or checksum
diff --git a/drivers/fpga/zynqmppl.c b/drivers/fpga/zynqmppl.c
index bf6f56e1c4..5fcca8d1b8 100644
--- a/drivers/fpga/zynqmppl.c
+++ b/drivers/fpga/zynqmppl.c
@@ -214,7 +214,9 @@ static int zynqmp_load(xilinx_desc **desc_ptr, const void *buf, size_t bsize,
 	fpga_desc *fdesc = container_of((void *)desc_ptr, fpga_desc, devdesc);
 
 	if (fdesc && fdesc->compatible &&
-	    !strcmp(fdesc->compatible, "u-boot,zynqmp-fpga-ddrauth")) {
+	    ( !strcmp(fdesc->compatible, "u-boot,zynqmp-fpga-ddrauth") ||
+	      !strcmp(fdesc->compatible, "u-boot,zynqmp-fpga-enc") )
+	      ) {
 		if (CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)) {
 			struct fpga_secure_info info = { 0 };
 
@@ -222,9 +224,15 @@ static int zynqmp_load(xilinx_desc **desc_ptr, const void *buf, size_t bsize,
 				printf("%s: Missing load operation\n", __func__);
 				return FPGA_FAIL;
 			}
-			/* DDR authentication */
-			info.authflag = 1;
-			info.encflag = 2;
+			if(!strcmp(fdesc->compatible+19, "enc")){
+			  /* Encryption using device key*/
+			  info.authflag = 2;
+			  info.encflag = 0;
+			} else {
+			  /* DDR authentication */
+			  info.authflag = 1;
+			  info.encflag = 2;
+			}
 			return desc->operations->loads(desc, buf, bsize, &info);
 		} else {
 			printf("No support for %s\n", fdesc->compatible);
-- 
2.35.1