mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-12 14:23:00 +00:00
54841ab50c
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>
136 lines
3.5 KiB
C
136 lines
3.5 KiB
C
/**
|
|
* Copyright 2010 Freescale Semiconductor
|
|
* Author: Timur Tabi <timur@freescale.com>
|
|
*
|
|
* 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 file provides support for the ngPIXIS, a board-specific FPGA used on
|
|
* some Freescale reference boards.
|
|
*
|
|
* A "switch" is black rectangular block on the motherboard. It contains
|
|
* eight "bits". The ngPIXIS has a set of memory-mapped registers (SWx) that
|
|
* shadow the actual physical switches. There is also another set of
|
|
* registers (ENx) that tell the ngPIXIS which bits of SWx should actually be
|
|
* used to override the values of the bits in the physical switches.
|
|
*
|
|
* The following macros need to be defined:
|
|
*
|
|
* PIXIS_BASE - The virtual address of the base of the PIXIS register map
|
|
*
|
|
* PIXIS_LBMAP_SWITCH - The switch number (i.e. the "x" in "SWx"). This value
|
|
* is used in the PIXIS_SW() macro to determine which offset in
|
|
* the PIXIS register map corresponds to the physical switch that controls
|
|
* the boot bank.
|
|
*
|
|
* PIXIS_LBMAP_MASK - A bit mask the defines which bits in SWx to use.
|
|
*
|
|
* PIXIS_LBMAP_SHIFT - The shift value that corresponds to PIXIS_LBMAP_MASK.
|
|
*
|
|
* PIXIS_LBMAP_ALTBANK - The value to program into SWx to tell the ngPIXIS to
|
|
* boot from the alternate bank.
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <command.h>
|
|
#include <watchdog.h>
|
|
#include <asm/cache.h>
|
|
#include <asm/io.h>
|
|
|
|
#include "ngpixis.h"
|
|
|
|
/*
|
|
* Reset the board. This ignores the ENx registers.
|
|
*/
|
|
void pixis_reset(void)
|
|
{
|
|
out_8(&pixis->rst, 0);
|
|
|
|
while (1);
|
|
}
|
|
|
|
/*
|
|
* Reset the board. Like pixis_reset(), but it honors the ENx registers.
|
|
*/
|
|
void pixis_bank_reset(void)
|
|
{
|
|
out_8(&pixis->vctl, 0);
|
|
out_8(&pixis->vctl, 1);
|
|
|
|
while (1);
|
|
}
|
|
|
|
/**
|
|
* Set the boot bank to the power-on default bank
|
|
*/
|
|
void clear_altbank(void)
|
|
{
|
|
/* Tell the ngPIXIS to use this the bits in the physical switch for the
|
|
* boot bank value, instead of the SWx register. We need to be careful
|
|
* only to set the bits in SWx that correspond to the boot bank.
|
|
*/
|
|
clrbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
|
|
}
|
|
|
|
/**
|
|
* Set the boot bank to the alternate bank
|
|
*/
|
|
void set_altbank(void)
|
|
{
|
|
/* Program the alternate bank number into the SWx register.
|
|
*/
|
|
clrsetbits_8(&PIXIS_SW(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK,
|
|
PIXIS_LBMAP_ALTBANK);
|
|
|
|
/* Tell the ngPIXIS to use this the bits in the SWx register for the
|
|
* boot bank value, instead of the physical switch. We need to be
|
|
* careful only to set the bits in SWx that correspond to the boot bank.
|
|
*/
|
|
setbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
|
|
}
|
|
|
|
|
|
int pixis_reset_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
|
|
{
|
|
unsigned int i;
|
|
char *p_altbank = NULL;
|
|
char *unknown_param = NULL;
|
|
|
|
/* No args is a simple reset request.
|
|
*/
|
|
if (argc <= 1)
|
|
pixis_reset();
|
|
|
|
for (i = 1; i < argc; i++) {
|
|
if (strcmp(argv[i], "altbank") == 0) {
|
|
p_altbank = argv[i];
|
|
continue;
|
|
}
|
|
|
|
unknown_param = argv[i];
|
|
}
|
|
|
|
if (unknown_param) {
|
|
printf("Invalid option: %s\n", unknown_param);
|
|
return 1;
|
|
}
|
|
|
|
if (p_altbank)
|
|
set_altbank();
|
|
else
|
|
clear_altbank();
|
|
|
|
pixis_bank_reset();
|
|
|
|
/* Shouldn't be reached. */
|
|
return 0;
|
|
}
|
|
|
|
U_BOOT_CMD(
|
|
pixis_reset, CONFIG_SYS_MAXARGS, 1, pixis_reset_cmd,
|
|
"Reset the board using the FPGA sequencer",
|
|
"- hard reset to default bank\n"
|
|
"pixis_reset altbank - reset to alternate bank\n"
|
|
);
|