rockchip: Add support for the SPI image

The Rockchip boot ROM requires a particular file format for booting from SPI.
It consists of a 512-byte header encoded with RC4, some padding and then up
to 32KB of executable code in 2KB blocks, separated by 2KB empty blocks.

Add support to mkimage so that an SPL image (u-boot-spl-dtb.bin) can be
converted to this format. This allows booting from SPI flash on supported
machines.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 119 insertions, 0 deletions

diff --git a/tools/rkspi.c b/tools/rkspi.c
new file mode 100644
index 0000000000..a3c4c73916
--- /dev/null
+++ b/tools/rkspi.c
@@ -0,0 +1,119 @@
+/*
+ * (C) Copyright 2015 Google,  Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ *
+ * See README.rockchip for details of the rkspi format
+ */
+
+#include "imagetool.h"
+#include <image.h>
+#include <rc4.h>
+#include "mkimage.h"
+#include "rkcommon.h"
+
+enum {
+	RKSPI_SPL_HDR_START	= RK_CODE1_OFFSET * RK_BLK_SIZE,
+	RKSPI_SPL_START		= RKSPI_SPL_HDR_START + 4,
+	RKSPI_HEADER_LEN	= RKSPI_SPL_START,
+	RKSPI_SECT_LEN		= RK_BLK_SIZE * 4,
+};
+
+static char dummy_hdr[RKSPI_HEADER_LEN];
+
+static int rkspi_check_params(struct image_tool_params *params)
+{
+	return 0;
+}
+
+static int rkspi_verify_header(unsigned char *buf, int size,
+			       struct image_tool_params *params)
+{
+	return 0;
+}
+
+static void rkspi_print_header(const void *buf)
+{
+}
+
+static void rkspi_set_header(void *buf, struct stat *sbuf, int ifd,
+			     struct image_tool_params *params)
+{
+	int sector;
+	unsigned int size;
+	int ret;
+
+	size = params->orig_file_size;
+	ret = rkcommon_set_header(buf, size);
+	debug("size %x\n", size);
+	if (ret) {
+		/* TODO(sjg@chromium.org): This method should return an error */
+		printf("Warning: SPL image is too large (size %#x) and will not boot\n",
+		       size);
+	}
+
+	memcpy(buf + RKSPI_SPL_HDR_START, "RK32", 4);
+
+	/*
+	 * Spread the image out so we only use the first 2KB of each 4KB
+	 * region. This is a feature of the SPI format required by the Rockchip
+	 * boot ROM. Its rationale is unknown.
+	 */
+	for (sector = size / RKSPI_SECT_LEN - 1; sector >= 0; sector--) {
+		printf("sector %u\n", sector);
+		memmove(buf + sector * RKSPI_SECT_LEN * 2,
+			buf + sector * RKSPI_SECT_LEN,
+			RKSPI_SECT_LEN);
+		memset(buf + sector * RKSPI_SECT_LEN * 2 + RKSPI_SECT_LEN,
+		       '\0', RKSPI_SECT_LEN);
+	}
+}
+
+static int rkspi_extract_subimage(void *buf, struct image_tool_params *params)
+{
+	return 0;
+}
+
+static int rkspi_check_image_type(uint8_t type)
+{
+	if (type == IH_TYPE_RKSPI)
+		return EXIT_SUCCESS;
+	else
+		return EXIT_FAILURE;
+}
+
+/* We pad the file out to a fixed size - this method returns that size */
+static int rkspi_vrec_header(struct image_tool_params *params,
+			     struct image_type_params *tparams)
+{
+	int pad_size;
+
+	pad_size = (RK_MAX_CODE1_SIZE + 0x7ff) / 0x800 * 0x800;
+	params->orig_file_size = pad_size;
+
+	/* We will double the image size due to the SPI format */
+	pad_size *= 2;
+	pad_size += RKSPI_SPL_HDR_START;
+	debug("pad_size %x\n", pad_size);
+
+	return pad_size - params->file_size;
+}
+
+/*
+ * rk_spi parameters
+ */
+U_BOOT_IMAGE_TYPE(
+	rkspi,
+	"Rockchip SPI Boot Image support",
+	RKSPI_HEADER_LEN,
+	dummy_hdr,
+	rkspi_check_params,
+	rkspi_verify_header,
+	rkspi_print_header,
+	rkspi_set_header,
+	rkspi_extract_subimage,
+	rkspi_check_image_type,
+	NULL,
+	rkspi_vrec_header
+);