u-boot/arch/powerpc/cpu/74xx_7xx/cpu.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

313 lines
6.6 KiB
C

/*
* (C) Copyright 2001
* Josh Huber <huber@mclx.com>, Mission Critical Linux, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* cpu.c
*
* CPU specific code
*
* written or collected and sometimes rewritten by
* Magnus Damm <damm@bitsmart.com>
*
* minor modifications by
* Wolfgang Denk <wd@denx.de>
*
* more modifications by
* Josh Huber <huber@mclx.com>
* added support for the 74xx series of cpus
* added support for the 7xx series of cpus
* made the code a little less hard-coded, and more auto-detectish
*/
#include <common.h>
#include <command.h>
#include <74xx_7xx.h>
#include <asm/cache.h>
#if defined(CONFIG_OF_LIBFDT)
#include <libfdt.h>
#include <fdt_support.h>
#endif
DECLARE_GLOBAL_DATA_PTR;
cpu_t
get_cpu_type(void)
{
uint pvr = get_pvr();
cpu_t type;
type = CPU_UNKNOWN;
switch (PVR_VER(pvr)) {
case 0x000c:
type = CPU_7400;
break;
case 0x0008:
type = CPU_750;
if (((pvr >> 8) & 0xff) == 0x01) {
type = CPU_750CX; /* old CX (80100 and 8010x?)*/
} else if (((pvr >> 8) & 0xff) == 0x22) {
type = CPU_750CX; /* CX (82201,82202) and CXe (82214) */
} else if (((pvr >> 8) & 0xff) == 0x33) {
type = CPU_750CX; /* CXe (83311) */
} else if (((pvr >> 12) & 0xF) == 0x3) {
type = CPU_755;
}
break;
case 0x7000:
type = CPU_750FX;
break;
case 0x7002:
type = CPU_750GX;
break;
case 0x800C:
type = CPU_7410;
break;
case 0x8000:
type = CPU_7450;
break;
case 0x8001:
type = CPU_7455;
break;
case 0x8002:
type = CPU_7457;
break;
case 0x8003:
type = CPU_7447A;
break;
case 0x8004:
type = CPU_7448;
break;
default:
break;
}
return type;
}
/* ------------------------------------------------------------------------- */
#if !defined(CONFIG_BAB7xx)
int checkcpu (void)
{
uint type = get_cpu_type();
uint pvr = get_pvr();
ulong clock = gd->cpu_clk;
char buf[32];
char *str;
puts ("CPU: ");
switch (type) {
case CPU_750CX:
printf ("750CX%s v%d.%d", (pvr&0xf0)?"e":"",
(pvr>>8) & 0xf,
pvr & 0xf);
goto PR_CLK;
case CPU_750:
str = "750";
break;
case CPU_750FX:
str = "750FX";
break;
case CPU_750GX:
str = "750GX";
break;
case CPU_755:
str = "755";
break;
case CPU_7400:
str = "MPC7400";
break;
case CPU_7410:
str = "MPC7410";
break;
case CPU_7447A:
str = "MPC7447A";
break;
case CPU_7448:
str = "MPC7448";
break;
case CPU_7450:
str = "MPC7450";
break;
case CPU_7455:
str = "MPC7455";
break;
case CPU_7457:
str = "MPC7457";
break;
default:
printf("Unknown CPU -- PVR: 0x%08x\n", pvr);
return -1;
}
printf ("%s v%d.%d", str, (pvr >> 8) & 0xFF, pvr & 0xFF);
PR_CLK:
printf (" @ %s MHz\n", strmhz(buf, clock));
return (0);
}
#endif
/* these two functions are unimplemented currently [josh] */
/* -------------------------------------------------------------------- */
/* L1 i-cache */
int
checkicache(void)
{
return 0; /* XXX */
}
/* -------------------------------------------------------------------- */
/* L1 d-cache */
int
checkdcache(void)
{
return 0; /* XXX */
}
/* -------------------------------------------------------------------- */
static inline void
soft_restart(unsigned long addr)
{
/* SRR0 has system reset vector, SRR1 has default MSR value */
/* rfi restores MSR from SRR1 and sets the PC to the SRR0 value */
__asm__ __volatile__ ("mtspr 26, %0" :: "r" (addr));
__asm__ __volatile__ ("li 4, (1 << 6)" ::: "r4");
__asm__ __volatile__ ("mtspr 27, 4");
__asm__ __volatile__ ("rfi");
while(1); /* not reached */
}
#if !defined(CONFIG_PCIPPC2) && \
!defined(CONFIG_BAB7xx) && \
!defined(CONFIG_ELPPC) && \
!defined(CONFIG_PPMC7XX)
/* no generic way to do board reset. simply call soft_reset. */
void
do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr;
/* flush and disable I/D cache */
__asm__ __volatile__ ("mfspr 3, 1008" ::: "r3");
__asm__ __volatile__ ("ori 5, 5, 0xcc00" ::: "r5");
__asm__ __volatile__ ("ori 4, 3, 0xc00" ::: "r4");
__asm__ __volatile__ ("andc 5, 3, 5" ::: "r5");
__asm__ __volatile__ ("sync");
__asm__ __volatile__ ("mtspr 1008, 4");
__asm__ __volatile__ ("isync");
__asm__ __volatile__ ("sync");
__asm__ __volatile__ ("mtspr 1008, 5");
__asm__ __volatile__ ("isync");
__asm__ __volatile__ ("sync");
#ifdef CONFIG_SYS_RESET_ADDRESS
addr = CONFIG_SYS_RESET_ADDRESS;
#else
/*
* note: when CONFIG_SYS_MONITOR_BASE points to a RAM address,
* CONFIG_SYS_MONITOR_BASE - sizeof (ulong) is usually a valid
* address. Better pick an address known to be invalid on your
* system and assign it to CONFIG_SYS_RESET_ADDRESS.
*/
addr = CONFIG_SYS_MONITOR_BASE - sizeof (ulong);
#endif
soft_restart(addr);
while(1); /* not reached */
}
#endif
/* ------------------------------------------------------------------------- */
/*
* For the 7400 the TB clock runs at 1/4 the cpu bus speed.
*/
#ifndef CONFIG_SYS_BUS_CLK
#define CONFIG_SYS_BUS_CLK gd->bus_clk
#endif
unsigned long get_tbclk(void)
{
return CONFIG_SYS_BUS_CLK / 4;
}
/* ------------------------------------------------------------------------- */
#if defined(CONFIG_WATCHDOG)
#if !defined(CONFIG_PCIPPC2) && !defined(CONFIG_BAB7xx)
void
watchdog_reset(void)
{
}
#endif /* !CONFIG_PCIPPC2 && !CONFIG_BAB7xx */
#endif /* CONFIG_WATCHDOG */
/* ------------------------------------------------------------------------- */
#ifdef CONFIG_OF_LIBFDT
void ft_cpu_setup(void *blob, bd_t *bd)
{
do_fixup_by_prop_u32(blob, "device_type", "cpu", 4,
"timebase-frequency", bd->bi_busfreq / 4, 1);
do_fixup_by_prop_u32(blob, "device_type", "cpu", 4,
"bus-frequency", bd->bi_busfreq, 1);
do_fixup_by_prop_u32(blob, "device_type", "cpu", 4,
"clock-frequency", bd->bi_intfreq, 1);
fdt_fixup_memory(blob, (u64)bd->bi_memstart, (u64)bd->bi_memsize);
fdt_fixup_ethernet(blob);
}
#endif
/* ------------------------------------------------------------------------- */