/* build a cdboot partition if there is an embedded boot floppy image */
int
cdpart(Disk *d)
{
uchar buf[2048];
ulong a, n;
uchar *p;
if(readdisk(d, buf, 17*2048, 2048) == -1
|| strcmp((char*)buf+1, "CD001\x01EL TORITO SPECIFICATION") != 0)
return 0;
p = buf + 0x47;
a = p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);
if(readdisk(d, buf, a*2048, 2048) == -1
|| memcmp((char*)buf, "\x01\x00\x00\x00", 4) != 0
|| memcmp((char*)buf+30, "\x55\xAA", 2) != 0
|| buf[0x20] != 0x88)
return 0;
p = buf+0x28;
a = p[0]|(p[1]<<8)|(p[2]<<16)|(p[3]<<24);
switch(buf[0x21]) {
case 1: n = 1200*1024; break;
case 2: n = 1440*1024; break;
case 3: n = 2880*1024; break;
default: return 0;
}
a = a * (uvlong)2048 / d->secsize;
n /= d->secsize;
addpart(d, "cdboot", a, a+n);
return 1;
}
void targa_readdisk(unsigned int col, unsigned int row,
BYTE *red, BYTE *green, BYTE *blue)
{
col *= 3;
*blue = (BYTE)readdisk(col, row);
*green = (BYTE)readdisk(++col, row);
*red = (BYTE)readdisk(col+1, row);
}
int boot_main(void)
{
struct elf32hdr eh;
struct elf32_phdr ph;
Elf32_Half i;
entry_t entry;
Elf32_Off pos = 0;
uart_puts("BL: Hello!\r\n");
struct mbr *mbr = (struct mbr *)MBR_ADDR;
uint32_t lba;
uintptr_t seg;
uint8_t *src = (uint8_t *)&(mbr->part_entry[1].first_sector_lba);
uint8_t *des = (uint8_t *)&lba;
for (int i = 0; i < sizeof(lba); ++i) {
des[i] = src[i];
}
/*
* Basically, we're reading a statically-linked ELF file.
* The logic is very simple: we locate every loadable segment
* in the ELF file, putting the content in appropriate memory
* address. After everything is loaded into the memory, jump
* to the entry address and continue execution.
*
* Ideally, we want to clean ".bss" section prior to jumping
* into the entry point. However, the space in MBR is very
* limited, so we'll leave the job to the kernel itself.
*/
/* Read the ELF header first */
readdisk(lba, pos, &eh, sizeof(eh));
pos = eh.e_phoff;
for (i = 0; i < eh.e_phnum; ++i) {
readdisk(lba, pos, &ph, sizeof(ph));
if (ph.p_type == PT_LOAD) {
seg = (void *)ph.p_paddr;
readdisk(lba, ph.p_offset, seg, ph.p_filesz);
}
pos += eh.e_phentsize;
}
entry = (entry_t)(eh.e_entry);
uart_puts("BL: Kernel loaded.\r\n");
(*entry)();
//spin:
while (1);
}
void main(void)
{
kputs("--DEBUG-- Hello world from BIOS in C!\n");
char mbr[SECTOR_SIZE];
readdisk(0,0,mbr,SECTOR_SIZE);
(*((void (*)(void*,void*))(VTRC2VTRE(mbr))))(&readdisk,mbr);
}
int
get_part(int disk, struct part_desc *pl)
{
int i, next, err;
long startsect;
err=readdisk(disk, 0, 1, &fs);
if (err) return err;
if (fs.magic!=FIRST_SECT_MAGIC)
return E2E_BADPART;
memset(pl,0,sizeof(*pl)*16);
for (i=0; i<4; i++) {
if (fs.part[i].sys_ind) {
pl[i].is_extended = fs.part[i].sys_ind==EXTENDED_PARTITION;
pl[i].start = fs.part[i].start_sectlo+(fs.part[i].start_secthi<<16);
pl[i].length = fs.part[i].nr_sectslo+(fs.part[i].nr_sectshi<<16);
pl[i].parttype = fs.part[i].sys_ind;
}
}
next=4;
for (i=0; i<4; i++) {
if (fs.part[i].sys_ind==EXTENDED_PARTITION) {
startsect = pl[i].start;
while (1) {
if (next==16)
return 0;
err=readdisk(disk, startsect, 1, &fs2);
if (err) return err;
if (fs2.magic!=FIRST_SECT_MAGIC)
return E2E_BADPART;
pl[next].start = startsect + fs2.part[0].start_sectlo+(fs2.part[0].start_secthi<<16);
pl[next].length = fs2.part[0].nr_sectslo+(fs2.part[0].nr_sectshi<<16);
next++;
if (fs2.part[1].sys_ind!=EXTENDED_PARTITION)
break;
startsect += fs2.part[1].start_sectlo+(fs2.part[1].start_secthi<<16);
}
}
}
return 0;
}
void writedisk(size_t sec_num, ssize_t offset, const void *buf, size_t len) {
while(len) {
readdisk(sec_num,0,NULL,0);
int slen=(len+offset<SECTOR_SIZE)?len:(SECTOR_SIZE-offset);
memcpy(DMAbuf+offset, buf, slen);
SET_DMA(DMA, DMAbuf, sec_num, DMA_WRITE);
while(DMA_ISWRITE(DMA));
buf+=slen;
sec_num++;
len-=slen;
offset=0;
}
}
int
getfstype(int disk, unsigned short parttype, unsigned long start)
{
static union {
u_char bytes[512];
u_short shorts[256];
u_long longs[128];
} testblock;
int err;
if (parttype == PART_SWAP)
return SWAP;
if (parttype == PART_DOS32)
return MSDOSFS;
err=readdisk(disk, start, 1, &testblock);
if (err) return -err;
#if 0
if (strncmp(testblock.bytes+3,"MSDOS",5)==0) /* There must be a better way to do this */
return MSDOSFS;
#endif
err=readdisk(disk, start+2, 1, &testblock);
if (err) return -err;
if (testblock.shorts[28]==EXT2_SUPER_MAGIC)
return EXT2FS;
err=readdisk(disk, start+7, 1, &testblock);
if (err) return -err;
if (memcmp(testblock.bytes+0x1f6, "SWAP-SPACE", 10)==0)
return SWAP;
return 0;
}
void
sbdiskhash(Shabuf *sb, vlong eoffset)
{
static uchar dbuf[4*M];
int n;
while(sb->offset < eoffset){
n = sizeof dbuf;
if(sb->offset+n > eoffset)
n = eoffset - sb->offset;
readdisk(dbuf, sb->offset, n);
sbupdate(sb, dbuf, sb->offset, n);
}
}
static uchar*
pagein(vlong offset, int len)
{
pageout();
if(offset >= partend){
memset(buf, 0xFB, sizeof buf);
return buf;
}
if(offset+len > partend){
memset(buf, 0xFB, sizeof buf);
len = partend - offset;
}
bufoffset = offset;
buflen = len;
readdisk(buf, offset, len);
memmove(sbuf, buf, len);
return buf;
}
int
p9part(Disk *d, char *name, ulong pstart)
{
char partbuf[512];
char *field[4], *line[Npart+1], *name2;
ulong start, end;
int i, n;
name2 = smprint("%s%s", d->prefix, name);
d = opendisk(name2, 1, 0);
if(!d) {
fprint(2, "%s: %r\n", name2);
free(name2);
return 0;
}
free(name2);
if(readdisk(d, partbuf, 512, sizeof partbuf) == -1)
return 0;
partbuf[sizeof partbuf - 1] = '\0';
if(strncmp(partbuf, "part ", 5) != 0
|| (n = getfields(partbuf, line, Npart+1, 0, "\n")) == 0)
return 0;
for(i = 0; i < n; i++) {
if(strncmp(line[i], "part ", 5) != 0)
break;
if(getfields(line[i], field, 4, 0, " ") != 4)
break;
start = strtoul(field[2], 0, 0);
end = strtoul(field[3], 0, 0);
if(start >= end)
break;
addpart(d, field[1], pstart+start, pstart+end);
}
return 0;
}