NetBSD/sys/arch/alpha/stand/common/prom.c
nathanw 3fe600dd5c Experimentation reveals that the implementation of GET_ENV on at least
some systems chokes if the buffer is not 8-byte aligned. GCC only aligns
character arrays to 4-byte boundaries by default, so it's possible to get
unlucky and die in the boot blocks with a "kernel stack not valid halt".

Avoid the problem by using a local, aligned buffer as the argument to GET_ENV,
and copying the result into the caller's buffer.

Should fix PRs port-alpha/17682 and port-alpha/17717.
CVS ----------------------------------------------------------------------
2002-07-30 20:36:42 +00:00

148 lines
3.1 KiB
C

/* $NetBSD: prom.c,v 1.11 2002/07/30 20:36:42 nathanw Exp $ */
/*
* Mach Operating System
* Copyright (c) 1992 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
#include <lib/libkern/libkern.h>
#include <sys/types.h>
#include <machine/prom.h>
#include <machine/rpb.h>
#include "common.h"
int console;
#if !defined(NO_GETCHAR) || !defined(NO_PUTCHAR_HALT)
static int test_getchar(int *);
#endif
static void putonechar(int c);
void
init_prom_calls()
{
extern struct prom_vec prom_dispatch_v;
struct rpb *r;
struct crb *c;
char buf[4];
r = (struct rpb *)HWRPB_ADDR;
c = (struct crb *)((u_int8_t *)r + r->rpb_crb_off);
prom_dispatch_v.routine_arg = c->crb_v_dispatch;
prom_dispatch_v.routine = c->crb_v_dispatch->entry_va;
/* Look for console tty. */
prom_getenv(PROM_E_TTY_DEV, buf, 4);
console = buf[0] - '0';
}
#if !defined(NO_GETCHAR) || !defined(NO_PUTCHAR_HALT)
static int
test_getchar(xc)
int *xc;
{
prom_return_t ret;
ret.bits = prom_dispatch(PROM_R_GETC, console);
*xc = ret.u.retval;
return ret.u.status == 0 || ret.u.status == 1;
}
#endif
#if !defined(NO_GETCHAR)
int
getchar()
{
int c;
for (;;) {
if (test_getchar(&c)) {
if (c == 3)
halt();
return c;
}
}
}
#endif
static void
putonechar(c)
int c;
{
prom_return_t ret;
char cbuf = c;
do {
ret.bits = prom_dispatch(PROM_R_PUTS, console, &cbuf, 1);
} while ((ret.u.retval & 1) == 0);
}
void
putchar(c)
int c;
{
#if !defined(NO_PUTCHAR_HALT)
int typed_c;
#endif
if (c == '\r' || c == '\n') {
putonechar('\r');
c = '\n';
}
putonechar(c);
#if !defined(NO_PUTCHAR_HALT)
if (test_getchar(&typed_c))
if (typed_c == 3)
halt();
#endif
}
int
prom_getenv(id, buf, len)
int id, len;
char *buf;
{
/*
* On at least some systems, the GETENV call requires a
* 8-byte-aligned buffer, or it bails out with a "kernel stack
* not valid halt". Provide a local, aligned buffer here and
* then copy to the caller's buffer.
*/
static char abuf[128] __attribute__((aligned (8)));
prom_return_t ret;
ret.bits = prom_dispatch(PROM_R_GETENV, id, abuf, 128);
if (ret.u.status & 0x4)
ret.u.retval = 0;
len = min(len - 1, ret.u.retval);
memcpy(buf, abuf, len);
buf[len] = '\0';
return (len);
}