ref: 1c7e58e75bc6b5620984f164d66354350b28dfe0
dir: /sys/src/boot/pc/sub.c/
#include <u.h>
#include <a.out.h>
#include "fns.h"
#include "mem.h"
void
putc(int c)
{
if(!nocga)
cgaputc(c);
if(uart >= 0)
uartputc(uart, c);
}
void
print(char *s)
{
while(*s != 0){
if(*s == '\n')
putc('\r');
putc(*s++);
}
}
int
readn(void *f, void *data, int len)
{
uchar *p, *e;
putc(' ');
p = data;
e = p + len;
while(p < e){
if(((ulong)p & 0xF000) == 0){
putc('\b');
putc(hex[((ulong)p>>16)&0xF]);
}
if((len = read(f, p, e - p)) <= 0)
break;
p += len;
}
putc('\b');
return p - (uchar*)data;
}
void
memmove(void *dst, void *src, int n)
{
uchar *d = dst;
uchar *s = src;
if(d < s){
while(n-- > 0)
*d++ = *s++;
} else if(d > s){
s += n;
d += n;
while(n-- > 0)
*--d = *--s;
}
}
int
memcmp(void *src, void *dst, int n)
{
uchar *d = dst;
uchar *s = src;
int r = 0;
while(n-- > 0){
r = *d++ - *s++;
if(r != 0)
break;
}
return r;
}
int
strlen(char *s)
{
char *p = s;
while(*p != '\0')
p++;
return p - s;
}
char*
strchr(char *s, int c)
{
for(; *s != 0; s++)
if(*s == c)
return s;
return nil;
}
void
memset(void *dst, int v, int n)
{
uchar *d = dst;
while(n > 0){
*d++ = v;
n--;
}
}
int
getc(void)
{
int c = 0;
if(!nokbd)
c = kbdgetc();
if(c == 0 && uart >= 0)
c = uartgetc(uart);
return c;
}
static int
readline(void *f, char *buf)
{
static char white[] = "\t ";
char *p;
p = buf;
do{
if(f == nil)
putc('>');
for(;;){
if(f == nil){
while((*p = getc()) == 0)
;
if(p == buf && (*p == '\b' || strchr(white, *p) != nil))
continue;
putc(*p);
if(*p == '\r')
putc('\n');
else if(*p == '\b'){
p--;
putc(' ');
putc('\b');
continue;
}
}else if(read(f, p, 1) <= 0)
return 0;
if(strchr("\r\n", *p) != nil)
break;
if(p == buf && strchr(white, *p) != nil)
continue; /* whitespace on start of line */
p++;
}
while(p > buf && strchr(white, p[-1]))
p--;
}while(p == buf);
*p = 0;
return p - buf;
}
static int
timeout(int ms)
{
long v;
volatile long *ticks = (long *) 0x46c;
v = *ticks;
while(ms > 0){
if(getc() != 0)
return 1;
if (v != *ticks) {
ms -= 55;
v = *ticks;
}
}
return 0;
}
#define BOOTLINE ((char*)CONFADDR)
#define BOOTLINELEN 64
#define BOOTARGS ((char*)(CONFADDR+BOOTLINELEN))
#define BOOTARGSLEN (4096-0x200-BOOTLINELEN)
char *confend;
static void apmconf(int);
static void e820conf(void);
static void ramdiskconf(int);
static void uartconf(char*);
static char*
getconf(char *s, char *buf)
{
char *p, *e;
int n;
n = strlen(s);
for(p = BOOTARGS; p < confend; p = e+1){
for(e = p+1; e < confend; e++)
if(*e == '\n')
break;
if(memcmp(p, s, n) == 0){
p += n;
n = e - p;
buf[n] = 0;
memmove(buf, p, n);
return buf;
}
}
return nil;
}
static int
delconf(char *s)
{
char *p, *e;
for(p = BOOTARGS; p < confend; p = e){
for(e = p+1; e < confend; e++){
if(*e == '\n'){
e++;
break;
}
}
if(memcmp(p, s, strlen(s)) == 0){
memmove(p, e, confend - e);
confend -= e - p;
*confend = 0;
return 1;
}
}
return 0;
}
char*
configure(void *f, char *path)
{
char *line, *kern, *s, *p;
int inblock, nowait, n;
static int once = 1;
if(once){
once = 0;
Clear:
memset(BOOTLINE, 0, BOOTLINELEN);
confend = BOOTARGS;
memset(confend, 0, BOOTARGSLEN);
e820conf();
ramdiskconf(0);
}
nowait = 1;
inblock = 0;
Loop:
while(readline(f, line = confend+1) > 0){
if(*line == 0 || strchr("#;=", *line) != nil)
continue;
if(*line == '['){
inblock = memcmp("[common]", line, 8) != 0;
continue;
}
if(memcmp("boot", line, 5) == 0){
nowait=1;
break;
}
if(memcmp("wait", line, 5) == 0){
nowait=0;
continue;
}
if(memcmp("show", line, 5) == 0){
print(BOOTARGS);
continue;
}
if(memcmp("clear", line, 5) == 0){
if(line[5] == '\0'){
print("ok\n");
goto Clear;
} else if(line[5] == ' ' && delconf(line+6))
print("ok\n");
continue;
}
if(inblock != 0 || (p = strchr(line, '=')) == nil)
continue;
*p++ = 0;
delconf(line);
if(memcmp("apm", line, 3) == 0){
apmconf(line[3] - '0');
continue;
}
if(memcmp("*nocga", line, 6) == 0)
nocga = 1;
if(memcmp("*nokbd", line, 6) == 0)
nokbd = 1;
if(memcmp("console", line, 8) == 0)
uartconf(p);
s = confend;
memmove(confend, line, n = strlen(line)); confend += n;
*confend++ = '=';
memmove(confend, p, n = strlen(p)); confend += n;
*confend++ = '\n';
*confend = 0;
print(s);
}
kern = getconf("bootfile=", path);
if(f != nil){
close(f);
f = nil;
if(kern != nil && (nowait==0 || timeout(1000)))
goto Loop;
}
if(kern == nil){
print("no bootfile\n");
goto Loop;
}
while((p = strchr(kern, '!')) != nil)
kern = p+1;
return kern;
}
static void
hexfmt(char *s, int i, ulong a)
{
s += i;
while(i > 0){
*--s = hex[a&15];
a >>= 4;
i--;
}
}
static void
addconfx(char *s, int w, ulong v)
{
int n;
n = strlen(s);
memmove(confend, s, n);
hexfmt(confend+n, w, v);
confend += n+w;
*confend = 0;
}
static void
apmconf(int id)
{
uchar *a;
char *s;
a = (uchar*)CONFADDR;
memset(a, 0, 20);
apm(id);
if(memcmp(a, "APM", 4) != 0)
return;
s = confend;
addconfx("apm", 1, id);
addconfx("=ax=", 4, *((ushort*)(a+4)));
addconfx(" ebx=", 8, *((ulong*)(a+12)));
addconfx(" cx=", 4, *((ushort*)(a+6)));
addconfx(" dx=", 4, *((ushort*)(a+8)));
addconfx(" di=", 4, *((ushort*)(a+10)));
addconfx(" esi=", 8, *((ulong*)(a+16)));
*confend++ = '\n';
*confend = 0;
print(s);
}
static void
e820conf(void)
{
struct {
uvlong base;
uvlong len;
ulong typ;
ulong ext;
} e;
uvlong v;
ulong bx;
char *s;
bx=0;
s = confend;
do{
bx = e820(bx, &e);
if(e.len != 0 && (e.ext & 3) == 1){
if(confend == s){
/* single entry <= 1MB is useless */
if(bx == 0 && e.typ == 1 && e.len <= 0x100000)
break;
memmove(confend, "*e820=", 6);
confend += 6;
}
addconfx("", 1, e.typ);
v = e.base;
addconfx(" 0x", 8, v>>32);
addconfx("", 8, v&0xffffffff);
v += e.len;
addconfx(" 0x", 8, v>>32);
addconfx("", 8, v&0xffffffff);
*confend++ = ' ';
}
} while(bx);
if(confend == s)
return;
*confend++ = '\n';
*confend = 0;
print(s);
}
static int
checksum(void *v, int n)
{
uchar *p, s;
s = 0;
p = v;
while(n-- > 0)
s += *p++;
return s;
}
static void
ramdiskconf(int id)
{
struct {
/* ACPI header */
char sig[4];
u32int len;
uchar revision;
uchar csum;
char oem_id[6];
char oem_table_id[8];
u32int oem_revision;
char asl_compiler_id[4];
u32int asl_compiler_revision;
u32int safe_hook;
/* MDI structure */
u16int bytes;
uchar version_minor;
uchar version_major;
u32int diskbuf;
u32int disksize;
u32int cmdline;
u32int oldint13;
u32int oldint15;
u16int olddosmem;
uchar bootloaderid;
uchar sector_shift;
u16int dpt_ptr;
} *mbft;
int shift;
char *s;
#define BDA ((uchar*)0x400)
mbft = (void*)((((BDA[0x14]<<8) | BDA[0x13])<<10) - 1024);
for(; (ulong)&mbft->sector_shift < 0xA0000; mbft = (void*)((ulong)mbft + 16)){
if(memcmp("mBFT", mbft, 4) == 0
&& mbft->len < 1024 && (uchar*)mbft + mbft->len > &mbft->sector_shift
&& checksum(mbft, mbft->len) == 0)
goto Found;
}
return;
Found:
shift = mbft->sector_shift;
if(shift == 0)
shift = 9;
s = confend;
addconfx("ramdisk", 1, id);
addconfx("=0x", 8, mbft->diskbuf);
addconfx(" 0x", 8, mbft->disksize<<shift);
addconfx(" 0x", 8, 1UL<<shift);
*confend++ = '\n';
*confend = 0;
print(s);
}
static void
uartconf(char *s)
{
if(*s >= '0' && *s <= '3'){
uart = *s - '0';
uartinit(uart, (7<<5) | 3); /* b9660 l8 s1 */
} else
uart = -1;
}
static ulong
beswal(ulong l)
{
uchar *p = (uchar*)&l;
return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
}
char*
bootkern(void *f)
{
uchar *e, *d, *t;
ulong n;
Exec ex;
while(a20() < 0)
print("a20 enable failed\n");
if(readn(f, &ex, sizeof(ex)) != sizeof(ex))
return "bad header";
e = (uchar*)(beswal(ex.entry) & ~0xF0000000UL);
switch(beswal(ex.magic)){
case S_MAGIC:
if(readn(f, e, 8) != 8)
goto Error;
case I_MAGIC:
break;
default:
return "bad magic";
}
t = e;
n = beswal(ex.text);
if(readn(f, t, n) != n)
goto Error;
t += n;
d = (uchar*)PGROUND((ulong)t);
memset(t, 0, d - t);
n = beswal(ex.data);
if(readn(f, d, n) != n)
goto Error;
d += n;
t = (uchar*)PGROUND((ulong)d);
t += PGROUND(beswal(ex.bss));
memset(d, 0, t - d);
close(f);
unload();
print("boot\n");
jump(e);
Error:
return "i/o error";
}