Update twrp.sh OTA with xz and sparse image support

base.mk

@@ -72,6 +72,9 @@ PRODUCT_COPY_FILES += \
 	device/phh/treble/twrp/twrp.sh:system/bin/twrp.sh \
 	device/phh/treble/twrp/busybox-armv7l:system/bin/busybox_phh
 
+PRODUCT_PACKAGES += \
+    simg2img_simple
+
 ifneq (,$(wildcard external/exfat))
 PRODUCT_PACKAGES += \
 	mkfs.exfat \

cmds/Android.bp

@@ -16,3 +16,11 @@ cc_binary {
 		"uevent.cpp",
 	],
 }
+
+cc_binary {
+	name: "simg2img_simple",
+	srcs: [
+		"simg2img_simple.cpp",
+	],
+	host_supported: true,
+}

cmds/simg2img_simple.cpp

@@ -0,0 +1,97 @@
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/sendfile.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct sparse_header {
+  uint32_t	magic;		/* 0xed26ff3a */
+  uint16_t	major_version;	/* (0x1) - reject images with higher major versions */
+  uint16_t	minor_version;	/* (0x0) - allow images with higer minor versions */
+  uint16_t	file_hdr_sz;	/* 28 bytes for first revision of the file format */
+  uint16_t	chunk_hdr_sz;	/* 12 bytes for first revision of the file format */
+  uint32_t	blk_sz;		/* block size in bytes, must be a multiple of 4 (4096) */
+  uint32_t	total_blks;	/* total blocks in the non-sparse output image */
+  uint32_t	total_chunks;	/* total chunks in the sparse input image */
+  uint32_t	image_checksum; /* CRC32 checksum of the original data, counting "don't care" */
+				/* as 0. Standard 802.3 polynomial, use a Public Domain */
+				/* table implementation */
+} sparse_header_t;
+
+#define SPARSE_HEADER_MAGIC	0xed26ff3a
+
+#define CHUNK_TYPE_RAW		0xCAC1
+#define CHUNK_TYPE_FILL		0xCAC2
+#define CHUNK_TYPE_DONT_CARE	0xCAC3
+#define CHUNK_TYPE_CRC32    0xCAC4
+
+typedef struct chunk_header {
+  uint16_t	chunk_type;	/* 0xCAC1 -> raw; 0xCAC2 -> fill; 0xCAC3 -> don't care */
+  uint16_t	reserved1;
+  uint32_t	chunk_sz;	/* in blocks in output image */
+  uint32_t	total_sz;	/* in bytes of chunk input file including chunk header and data */
+} chunk_header_t;
+
+/* Following a Raw or Fill or CRC32 chunk is data.
+ *  For a Raw chunk, it's the data in chunk_sz * blk_sz.
+ *  For a Fill chunk, it's 4 bytes of the fill data.
+ *  For a CRC32 chunk, it's 4 bytes of CRC32
+ */
+
+void nsendfile(int out_fd, int in_fd, size_t count) {
+	while(count) {
+		ssize_t res = splice(in_fd, NULL, out_fd, NULL, count, 0);
+		if(res == 0 || res == -1) exit(112);
+		count -= res;
+	}
+}
+
+int main() {
+	sparse_header_t hdr;
+	if(read(0, &hdr, sizeof(hdr)) != sizeof(hdr)) exit(1);
+	if(hdr.magic != SPARSE_HEADER_MAGIC) exit(2);
+	if(hdr.blk_sz != 4096) exit(6);
+	if(hdr.major_version != 1) exit(11);
+	if(hdr.minor_version != 0) exit(12);
+	if(hdr.file_hdr_sz != 28) exit(13);
+	if(hdr.chunk_hdr_sz != 12) exit(14);
+
+	char block[4096];
+	for(unsigned i=0; i<hdr.total_chunks; i++) {
+		chunk_header_t chunk;
+		if(read(0, &chunk, sizeof(chunk)) != sizeof(chunk)) exit(3);
+		if(chunk.chunk_type == CHUNK_TYPE_RAW) {
+			if(chunk.total_sz != sizeof(chunk_header_t) + (chunk.chunk_sz * hdr.blk_sz)) exit(7);
+
+			nsendfile(1, 0, hdr.blk_sz * chunk.chunk_sz);
+		} else if(chunk.chunk_type == CHUNK_TYPE_FILL) {
+			if(chunk.total_sz != 4 + sizeof(chunk_header_t)) exit(7);
+
+			uint32_t fill;
+			if(read(0, &fill, sizeof(fill)) != sizeof(fill)) exit(5);
+			//memset takes a char, not a int32, hence the check 
+			if(fill != 0) exit(6);
+			memset(block, fill, hdr.blk_sz);
+			for(unsigned i=0; i<chunk.chunk_sz; i++)
+				if(write(1, block, hdr.blk_sz) != hdr.blk_sz) exit(8);
+		} else if(chunk.chunk_type == CHUNK_TYPE_DONT_CARE) {
+			if(chunk.total_sz != sizeof(chunk_header_t)) exit(9);
+
+			memset(block, 0, hdr.blk_sz);
+			for(unsigned i=0; i<chunk.chunk_sz; i++)
+				if(write(1, block, hdr.blk_sz) != hdr.blk_sz) exit(10);
+		} else if(chunk.chunk_type == CHUNK_TYPE_CRC32) {
+			if(chunk.total_sz != 4 + sizeof(chunk_header_t)) exit(7);
+			uint32_t crc32;
+			if(read(0, &crc32, sizeof(crc32)) != sizeof(crc32)) exit(5);
+			/* ignore crc32 */
+		} else {
+			exit(4);
+		}
+	}
+	fsync(1);
+	return 0;
+}

twrp/twrp.sh

@@ -126,6 +126,9 @@ done
 
 blockdev --setrw "$system"
 
+
+for method in xz-sparse sparse raw;do
+	(
 		size="$(sed -En '2s/^([0-9]+) .*/\1/p' /cache/phh/block.map)"
 		block_size="$(sed -En '2s/.* ([0-9]*)$/\1/p' /cache/phh/block.map)"
 		n_ranges="$(sed -n 3p /cache/phh/block.map)"
@@ -134,10 +137,21 @@ for i in $(seq 1 $n_ranges);do
 			range_start="$(sed -En $((i+3))'s/^([0-9]+) .*/\1/p' /cache/phh/block.map)"
 			range_end="$(sed -En $((i+3))'s/^.* ([0-9]+)$/\1/p' /cache/phh/block.map)"
 			n_blocks=$((range_end-range_start))
-	busybox_phh dd bs=$block_size skip=$range_start seek=$block_id count=$n_blocks if=$dev of=$system
+			busybox_phh dd bs=$block_size skip=$range_start count=$n_blocks if=$dev
 
 			block_id=$((block_id+n_blocks))
 		done
+	) | (
+		set -e
+		if [ "$method" == xz-sparse ];then
+			busybox_phh xz -d -c | simg2img_simple > $system
+		elif [ "$method" == sparse ];then
+			simg2img_simple > $system
+		elif [ "$method" == raw ];then
+			cat > $system
+		fi
+	) && break
+done
 
 sync
 reboot