From 632971af15de952f04356e138ab81654add6e10b Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Sun, 21 Nov 2021 05:55:20 -0800
Subject: [PATCH] Properly support v4 image headers

---
 native/jni/magiskboot/bootimg.cpp | 33 +++++++++++++++++++++++++++----
 native/jni/magiskboot/bootimg.hpp | 14 +++++++++++++
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/native/jni/magiskboot/bootimg.cpp b/native/jni/magiskboot/bootimg.cpp
index 73365cbdf..743bec824 100644
--- a/native/jni/magiskboot/bootimg.cpp
+++ b/native/jni/magiskboot/bootimg.cpp
@@ -52,7 +52,8 @@ static size_t restore(int fd, const char *filename) {
 void dyn_img_hdr::print() {
     uint32_t ver = header_version();
     fprintf(stderr, "%-*s [%u]\n", PADDING, "HEADER_VER", ver);
-    fprintf(stderr, "%-*s [%u]\n", PADDING, "KERNEL_SZ", kernel_size());
+    if (!is_vendor)
+        fprintf(stderr, "%-*s [%u]\n", PADDING, "KERNEL_SZ", kernel_size());
     fprintf(stderr, "%-*s [%u]\n", PADDING, "RAMDISK_SZ", ramdisk_size());
     if (ver < 3)
         fprintf(stderr, "%-*s [%u]\n", PADDING, "SECOND_SZ", second_size());
@@ -219,8 +220,8 @@ static format_t check_fmt_lg(uint8_t *buf, unsigned sz) {
     format_t fmt = check_fmt(buf, sz);
     if (fmt == LZ4_LEGACY) {
         // We need to check if it is LZ4_LG
-        unsigned off = 4;
-        unsigned block_sz;
+        uint32_t off = 4;
+        uint32_t block_sz;
         while (off + sizeof(block_sz) <= sz) {
             memcpy(&block_sz, buf + off, sizeof(block_sz));
             off += sizeof(block_sz);
@@ -292,6 +293,13 @@ name = hdr_addr + off;                  \
 off += hdr->name##_size();              \
 off = do_align(off, hdr->page_size());
 
+#define get_ignore(name)                                            \
+if (hdr->name##_size()) {                                           \
+    auto blk_sz = do_align(hdr->name##_size(), hdr->page_size());   \
+    ignore_size += blk_sz;                                          \
+    off += blk_sz;                                                  \
+}
+
 void boot_img::parse_image(uint8_t *addr, format_t type) {
     hdr = create_hdr(addr, type);
 
@@ -314,6 +322,11 @@ void boot_img::parse_image(uint8_t *addr, format_t type) {
     get_block(recovery_dtbo);
     get_block(dtb);
 
+    ignore = hdr_addr + off;
+    get_ignore(signature)
+    get_ignore(vendor_ramdisk_table)
+    get_ignore(bootconfig)
+
     if (int dtb_off = find_dtb_offset(kernel, hdr->kernel_size()); dtb_off > 0) {
         kernel_dtb = kernel + dtb_off;
         hdr->kernel_dt_size = hdr->kernel_size() - dtb_off;
@@ -364,7 +377,13 @@ void boot_img::parse_image(uint8_t *addr, format_t type) {
         fprintf(stderr, "%-*s [%s]\n", PADDING, "KERNEL_FMT", fmt2name[k_fmt]);
     }
     if (auto size = hdr->ramdisk_size()) {
-        r_fmt = check_fmt_lg(ramdisk, size);
+        if (hdr->is_vendor && hdr->header_version() >= 4) {
+            // v4 vendor boot contains multiple ramdisks
+            // Do not try to mess with it for now
+            r_fmt = UNKNOWN;
+        } else {
+            r_fmt = check_fmt_lg(ramdisk, size);
+        }
         if (r_fmt == MTK) {
             fprintf(stderr, "MTK_RAMDISK_HDR\n");
             flags[MTK_RAMDISK] = true;
@@ -636,6 +655,12 @@ void repack(const char *src_img, const char *out_img, bool skip_comp) {
         file_align();
     }
 
+    // Directly copy ignored blobs
+    if (boot.ignore_size) {
+        // ignore_size should already be aligned
+        xwrite(fd, boot.ignore, boot.ignore_size);
+    }
+
     // Proprietary stuffs
     if (boot.flags[SEANDROID_FLAG]) {
         xwrite(fd, SEANDROID_MAGIC, 16);
diff --git a/native/jni/magiskboot/bootimg.hpp b/native/jni/magiskboot/bootimg.hpp
index 6929cb91f..4893848fb 100644
--- a/native/jni/magiskboot/bootimg.hpp
+++ b/native/jni/magiskboot/bootimg.hpp
@@ -367,6 +367,11 @@ struct dyn_img_hdr {
     decl_var(header_size, 32)
     decl_var(dtb_size, 32)
 
+    // v4 specific
+    decl_val(signature_size, uint32_t)
+    decl_val(vendor_ramdisk_table_size, uint32_t)
+    decl_val(bootconfig_size, uint32_t)
+
     virtual ~dyn_img_hdr() {
         free(raw);
     }
@@ -495,6 +500,8 @@ struct dyn_img_v3 : public dyn_img_hdr_boot {
 
 struct dyn_img_v4 : public dyn_img_v3 {
     impl_cls(v4)
+
+    impl_val(signature_size)
 };
 
 struct dyn_img_hdr_vendor : public dyn_img_hdr {
@@ -524,6 +531,9 @@ struct dyn_img_vnd_v3 : public dyn_img_hdr_vendor {
 
 struct dyn_img_vnd_v4 : public dyn_img_vnd_v3 {
     impl_cls(vnd_v4)
+
+    impl_val(vendor_ramdisk_table_size)
+    impl_val(bootconfig_size)
 };
 
 #undef __impl_cls
@@ -610,6 +620,10 @@ struct boot_img {
     uint8_t *recovery_dtbo;
     uint8_t *dtb;
 
+    // Pointer to blocks defined in header, but we do not care
+    uint8_t *ignore;
+    size_t ignore_size = 0;
+
     boot_img(const char *);
     ~boot_img();