ptgen: create separate images for gpt data structure

This patch creates 2 or 3 gpt images:
 image.start: PMBR + GPT Header
 image.entry: GPT Entry Table
 image.end:   GPT Entry Table + Alternative GPT HEADER

If GPT Entry table follow GPT Header without gap, then
image.entry will be joined to the end of image.start file.

Signed-off-by: Mikhail Kshevetskiy <[email protected]>

diff --git a/src/ptgen.c b/src/ptgen.c
index d675abda9ac6a35f218ac4979a3b1d7a217463d1..d9fb7442994ea44a0a7a9b2313dd912dff514e0f 100644 (file)
--- a/src/ptgen.c
+++ b/src/ptgen.c
@@ -172,6 +172,7 @@ bool use_guid_partition_table = false;
 struct partinfo parts[GPT_ENTRY_MAX];
 char *filename = NULL;
 
+int gpt_split_image = false;
 int gpt_alternate = false;
 uint64_t gpt_first_entry_sector = GPT_FIRST_ENTRY_SECTOR;
 uint64_t gpt_last_usable_sector = 0;
@@ -422,6 +423,7 @@ static int gen_gptable(uint32_t signature, guid_t guid, unsigned nr)
        uint64_t sect = GPT_SIZE + gpt_first_entry_sector;
        int fd, ret = -1;
        unsigned i, pmbr = 1;
+       char img_name[strlen(filename) + 20];
 
        memset(pte, 0, sizeof(struct pte) * MBR_ENTRY_MAX);
        memset(gpte, 0, GPT_ENTRY_SIZE * GPT_ENTRY_MAX);
@@ -516,8 +518,13 @@ static int gen_gptable(uint32_t signature, guid_t guid, unsigned nr)
                fprintf(stderr, "PartitionEntryLBA=%" PRIu64 ", FirstUsableLBA=%" PRIu64 ", LastUsableLBA=%" PRIu64 "\n",
                        gpt_first_entry_sector, gpt_first_entry_sector + GPT_SIZE, gpt_last_usable_sector);
 
-       if ((fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC, 0644)) < 0) {
-               fprintf(stderr, "Can't open output file '%s'\n",filename);
+       if (!gpt_split_image)
+               strcpy(img_name, filename);
+       else
+               snprintf(img_name, sizeof(img_name), "%s.start", filename);
+
+       if ((fd = open(img_name, O_WRONLY|O_CREAT|O_TRUNC, 0644)) < 0) {
+               fprintf(stderr, "Can't open output file '%s'\n",img_name);
                return ret;
        }
 
@@ -544,7 +551,24 @@ static int gen_gptable(uint32_t signature, guid_t guid, unsigned nr)
                goto fail;
        }
 
-       lseek(fd, gpt_first_entry_sector * DISK_SECTOR_SIZE, SEEK_SET);
+       lseek(fd, 2 * DISK_SECTOR_SIZE - 1, SEEK_SET);
+       if (write(fd, "\x00", 1) != 1) {
+               fputs("write failed.\n", stderr);
+               goto fail;
+       }
+
+       if (!gpt_split_image || (gpt_first_entry_sector == GPT_FIRST_ENTRY_SECTOR)) {
+               lseek(fd, gpt_first_entry_sector * DISK_SECTOR_SIZE, SEEK_SET);
+       } else {
+               close(fd);
+
+               snprintf(img_name, sizeof(img_name), "%s.entry", filename);
+               if ((fd = open(img_name, O_WRONLY|O_CREAT|O_TRUNC, 0644)) < 0) {
+                       fprintf(stderr, "Can't open output file '%s'\n",img_name);
+                       return ret;
+               }
+       }
+
        if (write(fd, &gpte, GPT_ENTRY_SIZE * GPT_ENTRY_MAX) != GPT_ENTRY_SIZE * GPT_ENTRY_MAX) {
                fputs("write failed.\n", stderr);
                goto fail;
@@ -557,7 +581,19 @@ static int gen_gptable(uint32_t signature, guid_t guid, unsigned nr)
                gpth.crc32 = 0;
                gpth.crc32 = cpu_to_le32(gpt_crc32(&gpth, GPT_HEADER_SIZE));
 
-               lseek(fd, end * DISK_SECTOR_SIZE - GPT_ENTRY_SIZE * GPT_ENTRY_MAX, SEEK_SET);
+               if (!gpt_split_image) {
+                       lseek(fd, end * DISK_SECTOR_SIZE - GPT_ENTRY_SIZE * GPT_ENTRY_MAX, SEEK_SET);
+               } else {
+                       close(fd);
+
+                       end = GPT_SIZE;
+                       snprintf(img_name, sizeof(img_name), "%s.end", filename);
+                       if ((fd = open(img_name, O_WRONLY|O_CREAT|O_TRUNC, 0644)) < 0) {
+                               fprintf(stderr, "Can't open output file '%s'\n",img_name);
+                               return ret;
+                       }
+               }
+
                if (write(fd, &gpte, GPT_ENTRY_SIZE * GPT_ENTRY_MAX) != GPT_ENTRY_SIZE * GPT_ENTRY_MAX) {
                        fputs("write failed.\n", stderr);
                        goto fail;
@@ -583,7 +619,7 @@ fail:
 
 static void usage(char *prog)
 {
-       fprintf(stderr, "Usage: %s [-v] [-n] [-g] -h <heads> -s <sectors> -o <outputfile>\n"
+       fprintf(stderr, "Usage: %s [-v] [-n] [-b] [-g] -h <heads> -s <sectors> -o <outputfile>\n"
                        "          [-a <part number>] [-l <align kB>] [-G <guid>]\n"
                        "          [-e <gpt_entry_offset>] [-d <gpt_disk_size>]\n"
                        "          [[-t <type> | -T <GPT part type>] [-r] [-N <name>] -p <size>[@<start>]...] \n", prog);
@@ -625,7 +661,7 @@ int main (int argc, char **argv)
        guid_t guid = GUID_INIT( signature, 0x2211, 0x4433, \
                        0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0x00);
 
-       while ((ch = getopt(argc, argv, "h:s:p:a:t:T:o:vnHN:gl:rS:G:e:d:")) != -1) {
+       while ((ch = getopt(argc, argv, "h:s:p:a:t:T:o:vnbHN:gl:rS:G:e:d:")) != -1) {
                switch (ch) {
                case 'o':
                        filename = optarg;
@@ -669,6 +705,10 @@ int main (int argc, char **argv)
                                gpt_last_usable_sector = total_sectors - GPT_SIZE - 2;
                        }
                        break;
+               case 'b':
+                       gpt_alternate = true;
+                       gpt_split_image = true;
+                       break;
                case 'h':
                        heads = (int)strtoul(optarg, NULL, 0);
                        break;