[U-Boot] [PATCH 1/7] image: android: Add functions for handling dtb field

[Sam Protsenko]

Android Boot Image v2 adds "DTB" payload (and corresponding field in the
image header). Provide functions for its handling:

  - android_image_get_dtb_by_index(): Obtain DTB file from "DTB" part of
    boot image, by file index
  - android_image_print_dtb_contents(): Iterate over all DTB files in
    "DTB" part of boot image and print those files info

"DTB" payload might be in one of the following formats:
  1. concatenated DTB files
  2. Android DTBO format

The latter requires "android-image-dt.c" functionality, so this commit
selects that file for building for CONFIG_ANDROID_BOOT_IMAGE option.

Right now this new functionality isn't used, but it can be used further.
As it's required to apply some specific dtbo file(s) from "dtbo"
partition, we can't automate this process inside of "bootm" command. But
we can do next:
  - come up with some new command like "bootimg" to extract dtb file
    from boot image (using functions from this patch)
  - extract desired dtbo files from "dtbo" partition using "dtimg"
    command
  - merge dtbo files into dtb file using "fdt apply" command
  - pass resulting dtb file into bootm command in order to boot the
    Android kernel with Android ramdisk from boot image

Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
---
 common/Makefile        |   2 +-
 common/image-android.c | 191 +++++++++++++++++++++++++++++++++++++++++
 include/image.h        |   5 ++
 3 files changed, 197 insertions(+), 1 deletion(-)

diff --git a/common/Makefile b/common/Makefile
index 302d8beaf3..7e5f5058b3 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -108,7 +108,7 @@ endif
 
 obj-y += image.o
 obj-$(CONFIG_ANDROID_AB) += android_ab.o
-obj-$(CONFIG_ANDROID_BOOT_IMAGE) += image-android.o
+obj-$(CONFIG_ANDROID_BOOT_IMAGE) += image-android.o image-android-dt.o
 obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o
 obj-$(CONFIG_$(SPL_TPL_)FIT) += image-fit.o
 obj-$(CONFIG_$(SPL_)MULTI_DTB_FIT) += boot_fit.o common_fit.o
diff --git a/common/image-android.c b/common/image-android.c
index 3564a64221..63e41ea5f1 100644
--- a/common/image-android.c
+++ b/common/image-android.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <env.h>
 #include <image.h>
+#include <image-android-dt.h>
 #include <android_image.h>
 #include <malloc.h>
 #include <errno.h>
@@ -195,6 +196,108 @@ int android_image_get_second(const struct andr_img_hdr *hdr,
 	return 0;
 }
 
+/**
+ * android_image_get_dtb_img_addr() - Get the address of DTB area in boot image.
+ * @hdr: Boot image header address
+ * @addr: Will contain the address of DTB area in boot image
+ *
+ * Return: true on success or false on fail.
+ */
+static bool android_image_get_dtb_img_addr(const struct andr_img_hdr *hdr,
+					   ulong *addr)
+{
+	ulong dtb_img_addr;
+
+	if (android_image_check_header(hdr)) {
+		printf("Error: Boot Image header is incorrect\n");
+		return false;
+	}
+
+	if (hdr->header_version < 2) {
+		printf("Error: header_version must be >= 2 to get dtb\n");
+		return false;
+	}
+
+	if (hdr->dtb_size == 0) {
+		printf("Error: dtb_size is 0\n");
+		return false;
+	}
+
+	/* Calculate the address of DTB area in boot image */
+	dtb_img_addr = (ulong)hdr;
+	dtb_img_addr += hdr->page_size;
+	dtb_img_addr += ALIGN(hdr->kernel_size, hdr->page_size);
+	dtb_img_addr += ALIGN(hdr->ramdisk_size, hdr->page_size);
+	dtb_img_addr += ALIGN(hdr->second_size, hdr->page_size);
+	dtb_img_addr += ALIGN(hdr->recovery_dtbo_size, hdr->page_size);
+
+	if (addr)
+		*addr = dtb_img_addr;
+
+	return true;
+}
+
+/**
+ * android_image_get_dtb_by_index() - Get address and size of file in DTB area.
+ * @hdr: Boot image header address
+ * @index: Index of desired DTB in DTB area (starting from 0)
+ * @addr: If not NULL, will contain address to specified DTB
+ * @size: If not NULL, will contain size of specified DTB
+ *
+ * Get the address and size of DTB file by its index in DTB area of Android
+ * Boot Image in RAM.
+ *
+ * Return: true on success or false on error.
+ */
+bool android_image_get_dtb_by_index(const struct andr_img_hdr *hdr, u32 index,
+				    ulong *addr, u32 *size)
+{
+	bool res;
+	ulong dtb_img_addr;	/* address of DTB part in boot image */
+	ulong dtb_addr;		/* address of DTB file with specified index  */
+	u32 i;			/* index iterator */
+
+	res = android_image_get_dtb_img_addr(hdr, &dtb_img_addr);
+	if (!res)
+		return false;
+
+	/* Check if DTB area of boot image is in DTBO format */
+	if (android_dt_check_header((ulong)dtb_img_addr)) {
+		return android_dt_get_fdt_by_index(dtb_img_addr, index, addr,
+						   size);
+	}
+
+	/* Find out the address of DTB with specified index in concat blobs */
+	i = 0;
+	dtb_addr = dtb_img_addr;
+	while (dtb_addr < dtb_img_addr + hdr->dtb_size) {
+		const struct fdt_header *fdt;
+		u32 dtb_size;
+
+		fdt = (const struct fdt_header *)dtb_addr;
+		if (fdt_check_header(fdt) != 0) {
+			printf("Error: Invalid FDT header for index %u\n", i);
+			return false;
+		}
+
+		dtb_size = fdt_totalsize(fdt);
+
+		if (i == index) {
+			if (size)
+				*size = dtb_size;
+			if (addr)
+				*addr = dtb_addr;
+			return true;
+		}
+
+		dtb_addr += dtb_size;
+		++i;
+	}
+
+	printf("Error: Index is out of bounds (%u/%u)\n", index, i);
+	return false;
+}
+
 #if !defined(CONFIG_SPL_BUILD)
 /**
  * android_print_contents - prints out the contents of the Android format image
@@ -246,4 +349,92 @@ void android_print_contents(const struct andr_img_hdr *hdr)
 		printf("%sdtb addr:             %llx\n", p, hdr->dtb_addr);
 	}
 }
+
+static bool android_image_print_dtb_info(const struct fdt_header *fdt,
+					 u32 index)
+{
+	int root_node_off;
+	u32 fdt_size;
+	const char *model;
+	const char *compatible;
+
+	root_node_off = fdt_path_offset(fdt, "/");
+	if (root_node_off < 0) {
+		printf("Error: Root node not found\n");
+		return false;
+	}
+
+	fdt_size = fdt_totalsize(fdt);
+	compatible = fdt_getprop(fdt, root_node_off, "compatible",
+				 NULL);
+	model = fdt_getprop(fdt, root_node_off, "model", NULL);
+
+	printf(" - DTB #%u:\n", index);
+	printf("           (DTB)size = %d\n", fdt_size);
+	printf("          (DTB)model = %s\n", model ? model : "(unknown)");
+	printf("     (DTB)compatible = %s\n",
+	       compatible ? compatible : "(unknown)");
+
+	return true;
+}
+
+/**
+ * android_image_print_dtb_contents() - Print info for DTB files in DTB area.
+ * @hdr: Boot image header address
+ *
+ * DTB payload in Android Boot Image v2+ can be in one of following formats:
+ *   1. Concatenated DTB files
+ *   2. Android DTBO format (see CONFIG_CMD_DTIMG for details)
+ *
+ * This function does next:
+ *   1. Prints out the format used in DTB area
+ *   2. Iterates over all DTB files in DTB area and prints out the info for
+ *      each file.
+ *
+ * Return: true on success or false on error.
+ */
+bool android_image_print_dtb_contents(const struct andr_img_hdr *hdr)
+{
+	bool res;
+	ulong dtb_img_addr;	/* address of DTB part in boot image */
+	ulong dtb_addr;		/* address of DTB file with specified index  */
+	u32 i;			/* index iterator */
+
+	res = android_image_get_dtb_img_addr(hdr, &dtb_img_addr);
+	if (!res)
+		return false;
+
+	/* Check if DTB area of boot image is in DTBO format */
+	if (android_dt_check_header((ulong)dtb_img_addr)) {
+		printf("## DTB area contents (DTBO format):\n");
+		android_dt_print_contents(dtb_img_addr);
+		return true;
+	}
+
+	printf("## DTB area contents (concat format):\n");
+
+	/* Iterate over concatenated DTB files */
+	i = 0;
+	dtb_addr = dtb_img_addr;
+	while (dtb_addr < dtb_img_addr + hdr->dtb_size) {
+		const struct fdt_header *fdt;
+		u32 dtb_size;
+
+		fdt = (const struct fdt_header *)dtb_addr;
+		if (fdt_check_header(fdt) != 0) {
+			printf("Error: Invalid FDT header for index %u\n", i);
+			return false;
+		}
+
+		res = android_image_print_dtb_info(fdt, i);
+		if (!res)
+			return false;
+
+		dtb_size = fdt_totalsize(fdt);
+		dtb_addr += dtb_size;
+		++i;
+	}
+
+	return true;
+}
 #endif
diff --git a/include/image.h b/include/image.h
index c1065c06f9..08eda41961 100644
--- a/include/image.h
+++ b/include/image.h
@@ -1333,10 +1333,15 @@ int android_image_get_ramdisk(const struct andr_img_hdr *hdr,
 			      ulong *rd_data, ulong *rd_len);
 int android_image_get_second(const struct andr_img_hdr *hdr,
 			      ulong *second_data, ulong *second_len);
+bool android_image_get_dtb_by_index(const struct andr_img_hdr *hdr, u32 index,
+				    ulong *addr, u32 *size);
 ulong android_image_get_end(const struct andr_img_hdr *hdr);
 ulong android_image_get_kload(const struct andr_img_hdr *hdr);
 ulong android_image_get_kcomp(const struct andr_img_hdr *hdr);
 void android_print_contents(const struct andr_img_hdr *hdr);
+#if !defined(CONFIG_SPL_BUILD)
+bool android_image_print_dtb_contents(const struct andr_img_hdr *hdr);
+#endif
 
 #endif /* CONFIG_ANDROID_BOOT_IMAGE */
 
-- 
2.23.0