From 6850dd945ea7eb0beedb25435bf2bc16741aec38 Mon Sep 17 00:00:00 2001
From: ths <ths@c046a42c-6fe2-441c-8c8c-71466251a162>
Date: Fri, 5 Jan 2007 18:56:04 +0000
Subject: [PATCH] Support for Bochs "growing" images, by Volker Ruppert.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2296 c046a42c-6fe2-441c-8c8c-71466251a162
---
 block-bochs.c | 40 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/block-bochs.c b/block-bochs.c
index febb4d3fd6..35e2a6cf01 100644
--- a/block-bochs.c
+++ b/block-bochs.c
@@ -28,7 +28,8 @@
 /**************************************************************/
 
 #define HEADER_MAGIC "Bochs Virtual HD Image"
-#define HEADER_VERSION 0x00010000
+#define HEADER_VERSION 0x00020000
+#define HEADER_V1 0x00010000
 #define HEADER_SIZE 512
 
 #define REDOLOG_TYPE "Redolog"
@@ -37,7 +38,7 @@
 // not allocated: 0xffffffff
 
 // always little-endian
-struct bochs_header {
+struct bochs_header_v1 {
     char magic[32]; // "Bochs Virtual HD Image"
     char type[16]; // "Redolog"
     char subtype[16]; // "Undoable" / "Volatile" / "Growing"
@@ -56,6 +57,27 @@ struct bochs_header {
     } extra;
 };
 
+// always little-endian
+struct bochs_header {
+    char magic[32]; // "Bochs Virtual HD Image"
+    char type[16]; // "Redolog"
+    char subtype[16]; // "Undoable" / "Volatile" / "Growing"
+    uint32_t version;
+    uint32_t header; // size of header
+    
+    union {
+	struct {
+	    uint32_t catalog; // num of entries
+	    uint32_t bitmap; // bitmap size
+	    uint32_t extent; // extent size
+	    uint32_t reserved; // for ???
+	    uint64_t disk; // disk size
+	    char padding[HEADER_SIZE - 64 - 8 - 24];
+	} redolog;
+	char padding[HEADER_SIZE - 64 - 8];
+    } extra;
+};
+
 typedef struct BDRVBochsState {
     int fd;
 
@@ -79,7 +101,8 @@ static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
     if (!strcmp(bochs->magic, HEADER_MAGIC) &&
 	!strcmp(bochs->type, REDOLOG_TYPE) &&
 	!strcmp(bochs->subtype, GROWING_TYPE) &&
-	(le32_to_cpu(bochs->version) == HEADER_VERSION))
+	((le32_to_cpu(bochs->version) == HEADER_VERSION) ||
+	(le32_to_cpu(bochs->version) == HEADER_V1)))
 	return 100;
 
     return 0;
@@ -90,6 +113,7 @@ static int bochs_open(BlockDriverState *bs, const char *filename, int flags)
     BDRVBochsState *s = bs->opaque;
     int fd, i;
     struct bochs_header bochs;
+    struct bochs_header_v1 header_v1;
 
     fd = open(filename, O_RDWR | O_BINARY);
     if (fd < 0) {
@@ -109,11 +133,17 @@ static int bochs_open(BlockDriverState *bs, const char *filename, int flags)
     if (strcmp(bochs.magic, HEADER_MAGIC) ||
         strcmp(bochs.type, REDOLOG_TYPE) ||
         strcmp(bochs.subtype, GROWING_TYPE) ||
-	(le32_to_cpu(bochs.version) != HEADER_VERSION)) {
+	((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
+	(le32_to_cpu(bochs.version) != HEADER_V1))) {
         goto fail;
     }
 
-    bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
+    if (le32_to_cpu(bochs.version) == HEADER_V1) {
+      memcpy(&header_v1, &bochs, sizeof(bochs));
+      bs->total_sectors = le64_to_cpu(header_v1.extra.redolog.disk) / 512;
+    } else {
+      bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
+    }
 
     lseek(s->fd, le32_to_cpu(bochs.header), SEEK_SET);
 
-- 
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