[PATCH v3 2/3] tools: mkimage: Add Allwinner eGON support

[Andre Przywara <andre.przywara@arm.com>]

So far we used the separate mksunxiboot tool for generating a bootable
image for Allwinner SPLs, probably just for historical reasons.

Use the mkimage framework to generate a so called eGON image the
Allwinner BROM expects.
The new image type is called "sunxi_egon", to differentiate it
from the (still to be implemented) secure boot TOC0 image.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 common/image.c        |   1 +
 include/image.h       |   1 +
 include/sunxi_image.h |   1 +
 tools/Makefile        |   1 +
 tools/sunxi_egon.c    | 136 ++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 140 insertions(+)
 create mode 100644 tools/sunxi_egon.c

diff --git a/common/image.c b/common/image.c
index 451fc689a89..6923dac7c07 100644
--- a/common/image.c
+++ b/common/image.c
@@ -189,6 +189,7 @@ static const table_entry_t uimage_type[] = {
 	{	IH_TYPE_STM32IMAGE, "stm32image", "STMicroelectronics STM32 Image" },
 	{	IH_TYPE_MTKIMAGE,   "mtk_image",   "MediaTek BootROM loadable Image" },
 	{	IH_TYPE_COPRO, "copro", "Coprocessor Image"},
+	{	IH_TYPE_SUNXI_EGON, "sunxi_egon",  "Allwinner eGON Boot Image" },
 	{	-1,		    "",		  "",			},
 };
 
diff --git a/include/image.h b/include/image.h
index 00bc03bebec..89bfca2155a 100644
--- a/include/image.h
+++ b/include/image.h
@@ -308,6 +308,7 @@ enum {
 	IH_TYPE_IMX8MIMAGE,		/* Freescale IMX8MBoot Image	*/
 	IH_TYPE_IMX8IMAGE,		/* Freescale IMX8Boot Image	*/
 	IH_TYPE_COPRO,			/* Coprocessor Image for remoteproc*/
+	IH_TYPE_SUNXI_EGON,		/* Allwinner eGON Boot Image */
 
 	IH_TYPE_COUNT,			/* Number of image types */
 };
diff --git a/include/sunxi_image.h b/include/sunxi_image.h
index d0d1290eb72..5b2055c0af3 100644
--- a/include/sunxi_image.h
+++ b/include/sunxi_image.h
@@ -13,6 +13,7 @@
 #define	SUNXI_IMAGE_H
 
 #define BOOT0_MAGIC		"eGON.BT0"
+#define BROM_STAMP_VALUE	0x5f0a6c39
 #define SPL_SIGNATURE		"SPL" /* marks "sunxi" SPL header */
 #define SPL_MAJOR_BITS		3
 #define SPL_MINOR_BITS		5
diff --git a/tools/Makefile b/tools/Makefile
index 51123fd9298..2c9a0c4c4e7 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -104,6 +104,7 @@ dumpimage-mkimage-objs := aisimage.o \
 			stm32image.o \
 			$(ROCKCHIP_OBS) \
 			socfpgaimage.o \
+			sunxi_egon.o \
 			lib/crc16.o \
 			lib/sha1.o \
 			lib/sha256.o \
diff --git a/tools/sunxi_egon.c b/tools/sunxi_egon.c
new file mode 100644
index 00000000000..8987794518a
--- /dev/null
+++ b/tools/sunxi_egon.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018 Arm Ltd.
+ */
+
+#include "imagetool.h"
+#include <image.h>
+
+#include <sunxi_image.h>
+
+/*
+ * NAND requires 8K padding. SD/eMMC gets away with 512 bytes,
+ * but let's use the larger padding to cover both.
+ */
+#define PAD_SIZE			8192
+
+static int egon_check_params(struct image_tool_params *params)
+{
+	/* We just need a binary image file. */
+	return !params->dflag;
+}
+
+static int egon_verify_header(unsigned char *ptr, int image_size,
+			      struct image_tool_params *params)
+{
+	const struct boot_file_head *header = (void *)ptr;
+	uint32_t length;
+
+	/* First 4 bytes must be an ARM branch instruction. */
+	if ((le32_to_cpu(header->b_instruction) & 0xff000000) != 0xea000000)
+		return EXIT_FAILURE;
+
+	if (memcmp(header->magic, BOOT0_MAGIC, sizeof(header->magic)))
+		return EXIT_FAILURE;
+
+	length = le32_to_cpu(header->length);
+	/* Must be at least 512 byte aligned. */
+	if (length & 511)
+		return EXIT_FAILURE;
+
+	/*
+	 * Image could also contain U-Boot proper, so could be bigger.
+	 * But it must not be shorter.
+	 */
+	if (image_size < length)
+		return EXIT_FAILURE;
+
+	return EXIT_SUCCESS;
+}
+
+static void egon_print_header(const void *buf)
+{
+	const struct boot_file_head *header = buf;
+
+	printf("Allwinner eGON image, size: %d bytes\n",
+	       le32_to_cpu(header->length));
+
+	if (memcmp(header->spl_signature, SPL_SIGNATURE, 3))
+		return;
+
+	printf("\tSPL header version %d.%d\n",
+	       header->spl_signature[3] >> SPL_MINOR_BITS,
+	       header->spl_signature[3] & ((1U << SPL_MINOR_BITS) - 1));
+	if (header->spl_signature[3] >= SPL_DT_HEADER_VERSION) {
+		uint32_t dt_name_offs = le32_to_cpu(header->dt_name_offset);
+
+		if (dt_name_offs > 0)
+			printf("\tDT name: %s\n", (char *)buf + dt_name_offs);
+	}
+}
+
+static void egon_set_header(void *buf, struct stat *sbuf, int infd,
+			    struct image_tool_params *params)
+{
+	struct boot_file_head *header = buf;
+	uint32_t *buf32 = buf;
+	uint32_t checksum = 0, value;
+	int i;
+
+	/* Generate an ARM branch instruction to jump over the header. */
+	value = 0xea000000 | (sizeof(struct boot_file_head) / 4 - 2);
+	header->b_instruction = cpu_to_le32(value);
+
+	memcpy(header->magic, BOOT0_MAGIC, sizeof(header->magic));
+	header->check_sum = cpu_to_le32(BROM_STAMP_VALUE);
+	header->length = cpu_to_le32(params->file_size);
+
+	memcpy(header->spl_signature, SPL_SIGNATURE, 3);
+
+	/* If an image name has been provided, use it as the DT name. */
+	if (params->imagename && params->imagename[0]) {
+		header->spl_signature[3] = SPL_DT_HEADER_VERSION;
+
+		value = offsetof(struct boot_file_head, string_pool);
+		header->dt_name_offset = cpu_to_le32(value);
+
+		strncpy((char *)header->string_pool, params->imagename, 52);
+		/* Make sure we have a terminating zero byte. */
+		((char *)header->string_pool)[51] = 0;
+	} else
+		header->spl_signature[3] = SPL_ENV_HEADER_VERSION;
+
+	/* Calculate the checksum. Yes, it's that simple. */
+	for (i = 0; i < sbuf->st_size / 4; i++)
+		checksum += le32_to_cpu(buf32[i]);
+	header->check_sum = cpu_to_le32(checksum);
+}
+
+static int egon_check_image_type(uint8_t type)
+{
+	return type == IH_TYPE_SUNXI_EGON ? 0 : 1;
+}
+
+static int egon_vrec_header(struct image_tool_params *params,
+			    struct image_type_params *tparams)
+{
+	tparams->hdr = calloc(sizeof(struct boot_file_head), 1);
+
+	/* Return padding to 8K blocks. */
+	return ALIGN(params->file_size, PAD_SIZE) - params->file_size;
+}
+
+U_BOOT_IMAGE_TYPE(
+	sunxi_egon,
+	"Allwinner eGON Boot Image support",
+	sizeof(struct boot_file_head),
+	NULL,
+	egon_check_params,
+	egon_verify_header,
+	egon_print_header,
+	egon_set_header,
+	NULL,
+	egon_check_image_type,
+	NULL,
+	egon_vrec_header
+);
-- 
2.17.5