sload.c

mips架构的bootloader,99左右的版本 但源代码现在没人更新了

/*************************************************************
 * File: mon/sload.c
 * Purpose: S-record loader
 * Author: Phil Bunce ([e-mail])
 * Revision History:
 *	970303	Removed duplicate globals
 *	970303	Switched chksum to static.
 *	970901	Added getNextSloadAdr(). Needed for sdtf cmd.
 *	970919	Changed getNextSloadAdr to getHighLoadAdr for BSO. Also
 *		changed code to make nextaddr be highest addr, not last.
 *	970920	Added msgs for illegal loads.
 *	980404	Added DL_MFLAG
 *	981212	Accept but ignore S5 recs (ghs)
 */

#include <stdio.h>
#include <termio.h>
#include <string.h>
#include <mon.h>

/*
 * Useful S-records for testing purposes:
 *	S0030000FC
 *	S309900200001234567860
 *	S7058002000073
 *
 */

static int chksum;
static Ulong nextaddr;
char recbuf[MAXREC];

/*************************************************************
*  sload(rec,offset,pLen,pFlags)
*	load Motorola S-records
*	returns:
*		-1 on error
*		0  at end
*		N  for data records (N = bytes transferred)
*/
sload(rec,offset,pLen,pFlags)
char *rec;
Ulong offset;
int *pLen,*pFlags;
{
int len,x,flags;

flags = *pFlags;
*pLen = 0;
len = 0;
if(rec[0] == 'S') {
	if (rec[1] >= '7' && rec[1] <= '9') {
		if (flags&DL_MFLAG) ; /* don't set entry address */
		else if (!endrec(rec,offset,flags)) return(0);
		else return(-1);
		}
	else if (rec[1] == 'D') {
		flags |= DL_DFLAG;
		*pFlags = flags;
		if (regChain) /* 970920 */
		  printf("ERROR: Reset controller before reloading driver.\n");
		}
	else if (rec[1] == '4') {
		if (dlsym(rec,(flags&DL_AFLAG)?0:offset,flags)) return(-1);
		}
	else if (rec[1] >= '1' && rec[1] <= '3') {
		if (!regChain && !(flags&DL_DFLAG))  /* 970920 */
			printf("ERROR: Load driver first.\n");
		else if (flags&DL_MFLAG) ; /* don't load memory */
		else if (x=datarec(rec,offset,&len,flags)) return(x);
		}
	else if (rec[1] == '0') return(1);
	else if (rec[1] == '5') ; /* accept but ignore S5 recs (ghs) */
	else return(-1);
	}
else return(-1);

if (len >= 0) {
	*pLen = len;
	return(1);
	}
else return(-1);
}

/*************************************************************
*  datarec(p,offset,pLen,flags)
*	handle an S-record data record
*/
datarec(p,offset,pLen,flags)
Uchar *p;
Ulong offset;
int *pLen,flags;
{
int len,i,cs;
Ulong addr,v;

*pLen = 0;
chksum = 0;
if (!gethex(&len,&p[2],2)) return(-1);
chksum += len;
if (len*2 != strlen(p)-4) return(-2);
i = 4; addr = 0;
switch (p[1]) {
	case '3' :
		if (!gethex(&v,&p[i],2)) return(-1);
		addr = (addr<<8)+v;
		chksum += v;
		i += 2;
		/* fall thru */
	case '2' :
		if (!gethex(&v,&p[i],2)) return(-1);
		addr = (addr<<8)+v;
		chksum += v;
		i += 2;
		/* fall thru */
	case '1' :
		if (!gethex(&v,&p[i],2)) return(-1);
		addr = (addr<<8)+v;
		chksum += v;
		if (!gethex(&v,&p[i+2],2)) return(-1);
		addr = (addr<<8)+v;
		chksum += v;
		break;
	default  : return(-3);
	}

#if 0
/* This stuff is to implement input files under PMON. It is not clear
 * whether something like this is possible under IMON. For the moment
 * I have disabled it.
 */
if (flags&DL_TFLAG) {
	if (getGpr(7) == 0) {
		topClientMem -= addr;
		putGpr(29,clienttos());
		tbase = topClientMem-addr;
		putGpr(7,topClientMem);
		}
	addr += tbase;
	}
else addr += offset;
#else
addr += offset;
#endif

p = &p[i+4];
len -= (i/2)+1; /* substract address and chksum fields from length */
for (i=0;i<len;i++,p+=2) {
	if (!gethex(&v,p,2)) return(-1);
	if (flags&DL_DFLAG) store_byte(addr++,v);
	else write_target(XT_MEM,addr++,v,1);
	chksum += v;
	}

if (!gethex(&cs,p,2)) return(-1);
if (!(flags&DL_IFLAG) && cs != ((~chksum)&0xff)) return(-4);
*pLen = i;
if (addr > nextaddr) nextaddr = addr;
return(0);
}

/*************************************************************
*  writec(fd,ch)
*/
writec(fd,ch)
int fd;
Uchar ch;
{
write(fd,&ch,1);
}

/*************************************************************
*  dlsym(p,offset,flags)
*	handle S4 records, i.e., symbols
*/
dlsym(p,offset,flags)
Uchar *p;
Ulong offset;
int flags;
{
Uchar val;
Ulong adr;
int len,csum;
Uchar name[LINESZ],*t;

/* 
S4LLAAAAAAAANNNNNNNN,AAAAAAAANNNNNN,AAAAAAAANNNNNNNNNN,CC
LL=length AAAAAAAA=addr NNNN,=name CC=checksum 
*/

if (flags&DL_DFLAG) return(0);	/* ignore syms if loading a driver */

p += 2; /* skip past S4 */
if (!gethex(&len,p,2)) return(1);
p += 2; /* skip past length */
for (;len > 2;) {
	if (!gethex(&adr,p,8)) return(2);
	p += 8; /* skip past addr */
	len -= 8;

	t = (Uchar *)strchr(p,',');
	if (t == 0) return(1);
	strNcpy(name,p,t-p);
	len -= t-p;

	if (!newsym(name,adr+offset)) return(3);

	p = t+1;
	}
if (!gethex(&csum,p,2)) return(4);
/* csum neither generated nor checked */
return(0);
}

/*************************************************************
*  endrec(p,offset,flags)
*	handle the S-record termination record
*/
endrec(p,offset,flags)
Uchar *p;
Ulong offset;
int flags;
{
Ulong adr;

switch (p[1]) {
	case '7' : if (!gethex(&adr,&p[4],8)) return(-1); break;
	case '8' : if (!gethex(&adr,&p[4],6)) return(-1); break;
	case '9' : if (!gethex(&adr,&p[4],4)) return(-1); break;
	}
if (!(flags&DL_DFLAG)) putPc(adr+offset);
return(0);
}

/*************************************************************
*  Ulong getHighLoadAdr()
*/
Ulong getHighLoadAdr()
{
return nextaddr;
}