Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

firmware-utils/ptgen: add support for EBR (MBR extended partition) #24

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

firmware-utils/ptgen: add support for EBR (MBR extended partition) #24

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
101 changes: 94 additions & 7 deletions src/ptgen.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -107,6 +107,7 @@ typedef struct {
#define MBR_DISK_SIGNATURE_OFFSET 440
#define MBR_PARTITION_ENTRY_OFFSET 446
#define MBR_BOOT_SIGNATURE_OFFSET 510
#define MBR_MSDOS_SYSTYPE_EXTENDED 5

#define DISK_SECTOR_SIZE 512

Expand Down Expand Up @@ -169,6 +170,12 @@ int sectors = -1;
int kb_align = 0;
bool ignore_null_sized_partition = false;
bool use_guid_partition_table = false;
bool use_mbr_extended_partition = false;
/**
* If only MBR: 4 primary partitions is enough, or use 3 primary partitions and 1 extended partition.
* If MBR with EBR: At least 5 are needed, 3 primary, 1 extended, 1 logic.
* If GPT: At most 128 can be used under Windows.
*/
struct partinfo parts[GPT_ENTRY_MAX];
char *filename = NULL;

Expand Down Expand Up @@ -324,7 +331,7 @@ static inline void init_utf16(char *str, uint16_t *buf, unsigned bufsize)
}

/* check the partition sizes and write the partition table */
static int gen_ptable(uint32_t signature, int nr)
static int gen_ptable(uint32_t signature, int nr, int realnr)
{
struct pte pte[MBR_ENTRY_MAX];
unsigned long start, len, sect = 0;
Expand Down Expand Up @@ -364,7 +371,7 @@ static int gen_ptable(uint32_t signature, int nr)
to_chs(start + len - 1, pte[i].chs_end);

if (verbose)
fprintf(stderr, "Partition %d: start=%ld, end=%ld, size=%ld\n",
fprintf(stderr, "MBR Partition %d: start=%ld, end=%ld, size=%ld\n",
i,
(long)start * DISK_SECTOR_SIZE,
(long)(start + len) * DISK_SECTOR_SIZE,
Expand Down Expand Up @@ -395,6 +402,70 @@ static int gen_ptable(uint32_t signature, int nr)
goto fail;
}

if (use_mbr_extended_partition) {
int _start = 0;
int offset = pte[3].start * 512;

for (i = nr; i < realnr; i++) {
unsigned long sect = 0;
int start = sectors, len;
struct pte ebrpte[2];
memset(ebrpte, 0, sizeof(ebrpte));

if (!parts[i].size) {
if (ignore_null_sized_partition)
continue;
fprintf(stderr, "Invalid size in partition %d!\n", i);
return -1;
}

ebrpte[0].active = 0;
ebrpte[0].type = parts[i].type;

if (kb_align != 0)
start = round_to_kb(start);
ebrpte[0].start = cpu_to_le32(start);

sect = start + parts[i].size * 2;
if (kb_align == 0)
sect = round_to_cyl(sect);
ebrpte[0].length = cpu_to_le32(len = sect - start);

to_chs(start, ebrpte[0].chs_start);
to_chs(start + len - 1, ebrpte[0].chs_end);

/* ebrpte[1] -> point next EBR */
if (realnr - i > 1) {
_start += sect;
ebrpte[1].active = 0;
ebrpte[1].type = MBR_MSDOS_SYSTYPE_EXTENDED;
ebrpte[1].start = cpu_to_le32(_start);
ebrpte[1].length = 512;
to_chs(_start, ebrpte[1].chs_start);
to_chs(_start + 511, ebrpte[1].chs_end);
}

if (verbose)
fprintf(stderr, "EBR Partition %d: start=%ld, end=%ld, size=%ld\n", i - nr, (long)start * 512, ((long)start + (long)len) * 512, (long)len * 512);
printf("%ld\n", (long)start * 512);
printf("%ld\n", (long)len * 512);

lseek(fd, offset + 446, SEEK_SET);
if (write(fd, ebrpte, sizeof(struct pte) * 2) != sizeof(struct pte) * 2) {
fprintf(stderr, "write failed.\n");
goto fail;
}

lseek(fd, offset + 510, SEEK_SET);
if (write(fd, "\x55\xaa", 2) != 2) {
fprintf(stderr, "write failed.\n");
goto fail;
}

offset += sect * 512;
}
}

ret = 0;
fail:
close(fd);
Expand Down Expand Up @@ -568,7 +639,7 @@ static int gen_gptable(uint32_t signature, guid_t guid, unsigned nr)

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] [-g] [-e] -h <heads> -s <sectors> -o <outputfile>\n"
" [-a <part number>] [-l <align kB>] [-G <guid>]\n"
" [[-t <type> | -T <GPT part type>] [-r] [-N <name>] -p <size>[@<start>]...] \n", prog);
exit(EXIT_FAILURE);
Expand Down Expand Up @@ -607,7 +678,7 @@ 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:")) != -1) {
while ((ch = getopt(argc, argv, "h:s:p:a:t:T:o:evnHN:gl:rS:G:")) != -1) {
switch (ch) {
case 'o':
filename = optarg;
Expand All @@ -624,17 +695,26 @@ int main (int argc, char **argv)
case 'H':
hybrid = 1;
break;
case 'e':
use_mbr_extended_partition = 1;
break;
case 'h':
heads = (int)strtoul(optarg, NULL, 0);
break;
case 's':
sectors = (int)strtoul(optarg, NULL, 0);
break;
case 'p':
if (part > GPT_ENTRY_MAX - 1 || (!use_guid_partition_table && part > 3)) {
fputs("Too many partitions\n", stderr);
if (part > GPT_ENTRY_MAX - 1 || ((!use_guid_partition_table && !use_mbr_extended_partition) && part > 3)) {
fputs("Too many partitions, please add the -e parameter to automatically enable MBR extended partition\n", stderr);
exit(EXIT_FAILURE);
}
if (part == 3 && use_mbr_extended_partition) {
parts[part++].type = MBR_MSDOS_SYSTYPE_EXTENDED;
parts[part].size = to_kbytes(optarg);
parts[part++].type = type;
break;
}
p = strchr(optarg, '@');
if (p) {
*(p++) = 0;
Expand Down Expand Up @@ -709,5 +789,12 @@ int main (int argc, char **argv)
return gen_gptable(signature, guid, part) ? EXIT_FAILURE : EXIT_SUCCESS;
}

return gen_ptable(signature, part) ? EXIT_FAILURE : EXIT_SUCCESS;
if (part > 4) {
int logic_parts_sizes = 0;
for (int i = 4; i < part; i++)
logic_parts_sizes += kb_align / 2 + parts[i].size;
parts[3].size = logic_parts_sizes;
}

return gen_ptable(signature, part > 3 ? 4 : part, part) ? EXIT_FAILURE : EXIT_SUCCESS;
}