image: android: Add functions for handling dtb field

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 blob from "DTB" part of
    boot image, by blob's index
  - android_image_print_dtb_contents(): Iterate over all DTB blobs in
    "DTB" part of boot image and print those blobs info

"DTB" payload might be in one of the following formats:
  1. concatenated DTB blobs
  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 blob(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 "abootimg" to extract dtb blob
    from boot image (using functions from this patch)
  - extract desired dtbo blobs from "dtbo" partition using "adtimg"
    command
  - merge dtbo blobs into dtb blob using "fdt apply" command
  - pass resulting dtb blob into bootm command in order to boot the
    Android kernel with Android ramdisk from boot image

Signed-off-by: Sam Protsenko <joe.skb7@gmail.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

3 files changed, 227 insertions, 1 deletions

diff --git a/common/Makefile b/common/Makefile
index 5f62b8d0b13..896e4af91d4 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 3564a64221d..220983655ad 100644
--- a/common/image-android.c
+++ b/common/image-android.c
@@ -6,10 +6,12 @@
 #include <common.h>
 #include <env.h>
 #include <image.h>
+#include <image-android-dt.h>
 #include <android_image.h>
 #include <malloc.h>
 #include <errno.h>
 #include <asm/unaligned.h>
+#include <mapmem.h>
 
 #define ANDROID_IMAGE_DEFAULT_KERNEL_ADDR	0x10008000
 
@@ -195,6 +197,121 @@ 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_addr: 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(ulong hdr_addr, ulong *addr)
+{
+	const struct andr_img_hdr *hdr;
+	ulong dtb_img_addr;
+	bool ret = true;
+
+	hdr = map_sysmem(hdr_addr, sizeof(*hdr));
+	if (android_image_check_header(hdr)) {
+		printf("Error: Boot Image header is incorrect\n");
+		ret = false;
+		goto exit;
+	}
+
+	if (hdr->header_version < 2) {
+		printf("Error: header_version must be >= 2 to get dtb\n");
+		ret = false;
+		goto exit;
+	}
+
+	if (hdr->dtb_size == 0) {
+		printf("Error: dtb_size is 0\n");
+		ret = false;
+		goto exit;
+	}
+
+	/* Calculate the address of DTB area in boot image */
+	dtb_img_addr = hdr_addr;
+	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);
+
+	*addr = dtb_img_addr;
+
+exit:
+	unmap_sysmem(hdr);
+	return ret;
+}
+
+/**
+ * android_image_get_dtb_by_index() - Get address and size of blob in DTB area.
+ * @hdr_addr: 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 blob 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(ulong hdr_addr, u32 index, ulong *addr,
+				    u32 *size)
+{
+	const struct andr_img_hdr *hdr;
+	bool res;
+	ulong dtb_img_addr;	/* address of DTB part in boot image */
+	u32 dtb_img_size;	/* size of DTB payload in boot image */
+	ulong dtb_addr;		/* address of DTB blob with specified index  */
+	u32 i;			/* index iterator */
+
+	res = android_image_get_dtb_img_addr(hdr_addr, &dtb_img_addr);
+	if (!res)
+		return false;
+
+	/* Check if DTB area of boot image is in DTBO format */
+	if (android_dt_check_header(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 */
+	hdr = map_sysmem(hdr_addr, sizeof(*hdr));
+	dtb_img_size = hdr->dtb_size;
+	unmap_sysmem(hdr);
+	i = 0;
+	dtb_addr = dtb_img_addr;
+	while (dtb_addr < dtb_img_addr + dtb_img_size) {
+		const struct fdt_header *fdt;
+		u32 dtb_size;
+
+		fdt = map_sysmem(dtb_addr, sizeof(*fdt));
+		if (fdt_check_header(fdt) != 0) {
+			unmap_sysmem(fdt);
+			printf("Error: Invalid FDT header for index %u\n", i);
+			return false;
+		}
+
+		dtb_size = fdt_totalsize(fdt);
+		unmap_sysmem(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 +363,108 @@ void android_print_contents(const struct andr_img_hdr *hdr)
 		printf("%sdtb addr:             %llx\n", p, hdr->dtb_addr);
 	}
 }
+
+/**
+ * android_image_print_dtb_info - Print info for one DTB blob in DTB area.
+ * @fdt: DTB header
+ * @index: Number of DTB blob in DTB area.
+ *
+ * Return: true on success or false on error.
+ */
+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 blobs in DTB area.
+ * @hdr_addr: Boot image header address
+ *
+ * DTB payload in Android Boot Image v2+ can be in one of following formats:
+ *   1. Concatenated DTB blobs
+ *   2. Android DTBO format (see CONFIG_CMD_ADTIMG for details)
+ *
+ * This function does next:
+ *   1. Prints out the format used in DTB area
+ *   2. Iterates over all DTB blobs in DTB area and prints out the info for
+ *      each blob.
+ *
+ * Return: true on success or false on error.
+ */
+bool android_image_print_dtb_contents(ulong hdr_addr)
+{
+	const struct andr_img_hdr *hdr;
+	bool res;
+	ulong dtb_img_addr;	/* address of DTB part in boot image */
+	u32 dtb_img_size;	/* size of DTB payload in boot image */
+	ulong dtb_addr;		/* address of DTB blob with specified index  */
+	u32 i;			/* index iterator */
+
+	res = android_image_get_dtb_img_addr(hdr_addr, &dtb_img_addr);
+	if (!res)
+		return false;
+
+	/* Check if DTB area of boot image is in DTBO format */
+	if (android_dt_check_header(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 blobs */
+	hdr = map_sysmem(hdr_addr, sizeof(*hdr));
+	dtb_img_size = hdr->dtb_size;
+	unmap_sysmem(hdr);
+	i = 0;
+	dtb_addr = dtb_img_addr;
+	while (dtb_addr < dtb_img_addr + dtb_img_size) {
+		const struct fdt_header *fdt;
+		u32 dtb_size;
+
+		fdt = map_sysmem(dtb_addr, sizeof(*fdt));
+		if (fdt_check_header(fdt) != 0) {
+			unmap_sysmem(fdt);
+			printf("Error: Invalid FDT header for index %u\n", i);
+			return false;
+		}
+
+		res = android_image_print_dtb_info(fdt, i);
+		if (!res) {
+			unmap_sysmem(fdt);
+			return false;
+		}
+
+		dtb_size = fdt_totalsize(fdt);
+		unmap_sysmem(fdt);
+		dtb_addr += dtb_size;
+		++i;
+	}
+
+	return true;
+}
 #endif
diff --git a/include/image.h b/include/image.h
index 9c6b6d6054b..4e36b87f42f 100644
--- a/include/image.h
+++ b/include/image.h
@@ -1425,10 +1425,15 @@ 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(ulong hdr_addr, 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(ulong hdr_addr);
+#endif
 
 #endif /* CONFIG_ANDROID_BOOT_IMAGE */