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#include "boot.h"
/*
* this doesn't yet use the crc
*/
typedef struct Uboot Uboot;
struct Uboot {
Queue* iq;
Block* partial;
ulong csum;
long bno;
uchar buf[64];
int nleft;
int ntimeout;
};
static Uboot uboot;
ulong crc32(void *buf, int n, ulong crc);
static void
uartbrecv(uchar *p, int n)
{
Uboot *ub;
Block *b;
ub = &uboot;
if(n > 0 && ub->iq != nil){
b = iallocb(n);
memmove(b->wp, p, n);
b->wp += n;
qbwrite(ub->iq, b);
}
}
int
uartinit(void)
{
return 1<<0;
}
Partition*
setuartpart(int, char *s)
{
static Partition pp[1];
if(strcmp(s, "boot") != 0 && strcmp(s, "disk") != 0)
return 0;
pp[0].start = 0;
pp[0].end = 2*1024*1024;
strcpy(pp[0].name, "boot");
return pp;
}
long
uartseek(int, long)
{
/* start the boot */
if(uboot.iq == nil)
uboot.iq = qopen(64*1024, 0, 0, 0);
if(uboot.partial){
freeb(uboot.partial);
uboot.partial = 0;
}
print("uart: start transmission\n");
uartsetboot(uartbrecv);
uboot.csum = ~0;
uboot.bno = 0;
uboot.nleft = 0;
uboot.ntimeout = 0;
return 0;
}
static long
uartreadn(void *buf, int nb)
{
ulong start;
Uboot *ub;
int l;
Block *b;
uchar *p;
p = buf;
ub = &uboot;
start = m->ticks;
while(nb > 0){
b = ub->partial;
ub->partial = nil;
if(b == nil){
ub->ntimeout = 0;
while((b = qget(ub->iq)) == 0){
if(TK2MS(m->ticks - start) >= 15*1000){
if(++ub->ntimeout >= 3){
print("uart: timeout\n");
return 0;
}
uartputs("n", 1);
}
}
}
l = BLEN(b);
if(l > nb)
l = nb;
memmove(p, b->rp, l);
b->rp += l;
if(b->rp >= b->wp)
freeb(b);
else
ub->partial = b;
nb -= l;
p += l;
}
return p-(uchar*)buf;
}
long
uartread(int, void *buf, long n)
{
uchar *p;
int l;
static uchar lbuf[64];
p = buf;
if((l = uboot.nleft) > 0){
if(l > n)
l = n;
uboot.nleft -= l;
memmove(p, uboot.buf, l);
p += l;
n -= l;
}
while(n > 0){
l = uartreadn(lbuf, sizeof(lbuf));
if(l < sizeof(lbuf))
return 0;
if(l > n){
uboot.nleft = l-n;
memmove(uboot.buf, lbuf+n, uboot.nleft);
l = n;
}
memmove(p, lbuf, l);
n -= l;
p += l;
uboot.bno++;
uartputs("y", 1);
}
return p-(uchar*)buf;
}
/*
* from Rob Warnock
*/
static ulong crc32tab[256]; /* initialised on first call to crc32 */
enum {
CRC32POLY = 0x04c11db7 /* AUTODIN II, Ethernet, & FDDI */
};
/*
* Build auxiliary table for parallel byte-at-a-time CRC-32.
*/
static void
initcrc32(void)
{
int i, j;
ulong c;
for(i = 0; i < 256; i++) {
for(c = i << 24, j = 8; j > 0; j--)
if(c & (1<<31))
c = (c<<1) ^ CRC32POLY;
else
c <<= 1;
crc32tab[i] = c;
}
}
ulong
crc32(void *buf, int n, ulong crc)
{
uchar *p;
if(crc32tab[1] == 0)
initcrc32();
crc = ~crc;
for(p = buf; --n >= 0;)
crc = (crc << 8) ^ crc32tab[(crc >> 24) ^ *p++];
return ~crc;
}
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