Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include "flashfs.h"

char*   prog;
ulong   sectsize;
ulong   nsects;
uchar*  sectbuff;
int     readonly;
ulong   delta;
int     eparity;

uchar   magic[] = { MAGIC0, MAGIC1, MAGIC2, FFSVERS };

int
putc3(uchar *buff, ulong v)
{
        if(v < (1 << 7)) {
                buff[0] = v;
                return 1;
        }

        if(v < (1 << 13)) {
                buff[0] = 0x80 | (v >> 7);
                buff[1] = v & ((1 << 7) - 1);
                return 2;
        }

        if(v < (1 << 21)) {
                buff[0] = 0x80 | (v >> 15);
                buff[1] = 0x80 | ((v >> 8) & ((1 << 7) - 1));
                buff[2] = v;
                return 3;
        }

        fprint(2, "%s: putc3 fail 0x%lux, called from %#p\n", prog, v, getcallerpc(&buff));
        abort();
        return -1;
}

int
getc3(uchar *buff, ulong *p)
{
        int c, d;

        c = buff[0];
        if((c & 0x80) == 0) {
                *p = c;
                return 1;
        }

        c &= ~0x80;
        d = buff[1];
        if((d & 0x80) == 0) {
                *p = (c << 7) | d;
                return 2;
        }

        d &= ~0x80;
        *p = (c << 15) | (d << 8) | buff[2];
        return 3;
}

ulong
get4(uchar *b)
{
        return  (b[0] <<  0) |
                (b[1] <<  8) |
                (b[2] << 16) |
                (b[3] << 24);
}

void
put4(uchar *b, ulong v)
{
        b[0] = v >>  0;
        b[1] = v >>  8;
        b[2] = v >> 16;
        b[3] = v >> 24;
}