rockchip: mkimage: pad the header to 8-bytes (using a 'nop') for RK3399

The RK3399 boot code (running as AArch64) poses a bit of a challenge
for SPL image generation:
 * The BootROM will start execution right after the 4-byte header (at
   the odd instruction word loaded into SRAM at 0xff8c2004, with the
   'RK33' boot magic residing at 0xff8c2000).
 * The default padding (during ELF generation) for AArch64 is 0x0,
   which is an illegal instruction and the .text section needs to be
   naturally aligned (someone might locate a 64bit constant relative
   to the section start and unaligned loads trigger a fault for all
   privileged modes of an ARMv8)... so we can't simply define the
   CONFIG_SPL_TEXT_BASE option to the odd address (0xff8c2004).
 * Finally, we don't want to change the values used for padding of
   the SPL .text section for all ARMv8 targets to the instruction
   word encoding 'nop', as this would affect all padding in this
   section and might hide errors that would otherwise quickly trigger
   an illegal insn exception.

To deal with this situation, we modify the rkimage generation to
 - understand the fact that the RK3399 needs to pad the header to an
   8 byte boundary using an AArch64 'nop'
 - the necessary logic to adjust the header_size (which controls the
   location where the payload is copied into the image) and to insert
   this padding (AArch64 insn words are always little-endian) into
   the image following the 4-byte header magic.

X-AffectedPlatforms: RK3399-Q7
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Klaus Goger <klaus.goger@theobroma-systems.com>

1 files changed, 5 insertions, 12 deletions

diff --git a/tools/rksd.c b/tools/rksd.c
index e55c522..ac8a67d 100644
--- a/tools/rksd.c
+++ b/tools/rksd.c
@@ -13,8 +13,6 @@
 #include "mkimage.h"
 #include "rkcommon.h"
 
-static char dummy_hdr[RK_IMAGE_HEADER_LEN];
-
 static int rksd_verify_header(unsigned char *buf,  int size,
 				 struct image_tool_params *params)
 {
@@ -38,13 +36,6 @@ static void rksd_set_header(void *buf,  struct stat *sbuf,  int ifd,
 		printf("Warning: SPL image is too large (size %#x) and will not boot\n",
 		       size);
 	}
-
-	memcpy(buf + RK_SPL_HDR_START, rkcommon_get_spl_hdr(params),
-	       RK_SPL_HDR_SIZE);
-
-	if (rkcommon_need_rc4_spl(params))
-		rkcommon_rc4_encode_spl(buf, RK_SPL_HDR_START,
-					params->file_size - RK_SPL_HDR_START);
 }
 
 static int rksd_extract_subimage(void *buf,  struct image_tool_params *params)
@@ -66,10 +57,12 @@ static int rksd_vrec_header(struct image_tool_params *params,
 {
 	int pad_size;
 
+	rkcommon_vrec_header(params, tparams);
+
 	pad_size = RK_SPL_HDR_START + rkcommon_get_spl_size(params);
 	debug("pad_size %x\n", pad_size);
 
-	return pad_size - params->file_size;
+	return pad_size - params->file_size - tparams->header_size;
 }
 
 /*
@@ -78,8 +71,8 @@ static int rksd_vrec_header(struct image_tool_params *params,
 U_BOOT_IMAGE_TYPE(
 	rksd,
 	"Rockchip SD Boot Image support",
-	RK_IMAGE_HEADER_LEN,
-	dummy_hdr,
+	0,
+	NULL,
 	rkcommon_check_params,
 	rksd_verify_header,
 	rksd_print_header,