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#include "project.h"
void
mbr_entry_show (MBR_entry * e)
{
printf (" flags %02x start chs %5d/%3d/%2d start sector %10d\n",
e->bootable,
MBR_CYLINDER (e->chs_start.cs),
e->chs_start.head, MBR_SECTOR (e->chs_start.cs), e->start);
printf (" system %02x end chs %5d/%3d/%2d end sector %10d\n",
e->system,
MBR_CYLINDER (e->chs_end.cs),
e->chs_end.head, MBR_SECTOR (e->chs_end.cs),
e->size + e->start - 1);
}
void
mbr_show (MBR * m)
{
int i;
printf (" PMBR:\n");
for (i = 0; i < 4; ++i)
{
if (m->entry[i].system)
{
printf (" Entry %d:\n", i);
mbr_entry_show (&m->entry[i]);
}
}
if (memcmp (m->signature, MBR_SIGNATURE, sizeof (m->signature)))
{
printf (" Signature INVALID\n");
}
else
{
printf (" Signature valid\n");
}
}
MBR
mbr_new (uint64_t lbas)
{
uint64_t cyls = lbas;
MBR ret = { 0 };
cyls = cyls / (63 * 255);
if (cyls > 1023)
cyls = 1023;
ret.entry[0].bootable = 0;
ret.entry[0].chs_start.cs = MBR_CS (0, 1);
ret.entry[0].system = MBR_PARTITION_TYPE_EFI;
ret.entry[0].chs_end.head = 254;
ret.entry[0].chs_end.cs = MBR_CS (cyls, 63);
ret.entry[0].start = 1;
ret.entry[0].size = lbas - 1;
memcpy (ret.signature, MBR_SIGNATURE, sizeof (ret.signature));
return ret;
}
static CHS
sector_to_chs (uint32_t lba)
{
CHS ret;
int c;
int h;
int s;
c = lba / (63 * 255);
if (c > 1023)
{
ret.head = 254;
ret.cs = MBR_CS (1023, 63);
return ret;
}
lba -= (c * 63 * 255);
h = lba / 63;
lba -= (h * 63);
s = lba + 1;
ret.head = h;
ret.cs = MBR_CS (c, s);
return ret;
}
static CHS
invalid_chs (void)
{
CHS ret;
ret.head = 254;
ret.cs = MBR_CS (1023, 63);
return ret;
}
void
mbr_entry_from_gpt_entry (MBR_entry * m, GPT_header * h, GPT_entry * g,
int bootable, uint8_t type)
{
MBR ret = { 0 };
uint32_t start = g->start;
uint32_t end = g->end;
m->system = type;
m->bootable = bootable ? MBR_PARTITION_BOOTABLE : 0x00;
m->chs_start = invalid_chs ();
m->chs_end = invalid_chs ();
m->start = start;
m->size = (end - start) + 1;
if (type == MBR_PARTITION_TYPE_EFI)
{
m->size += m->start -1;
m->start = 1;
}
}
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