u-boot/board/freescale/m5249evb/m5249evb.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

113 lines
3.2 KiB
C

/*
* (C) Copyright 2004
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* 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
*/
#include <common.h>
#include <command.h>
#include <malloc.h>
#include <asm/immap.h>
/* Prototypes */
int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
int checkboard (void) {
ulong val;
uchar val8;
puts ("Board: ");
puts("Freescale M5249EVB");
val8 = ((uchar)~((uchar)mbar2_readLong(MCFSIM_GPIO1_READ) >> 4)) & 0xf;
printf(" (Switch=%1X)\n", val8);
/*
* Set LED on
*/
val = mbar2_readLong(MCFSIM_GPIO1_OUT) & ~CONFIG_SYS_GPIO1_LED;
mbar2_writeLong(MCFSIM_GPIO1_OUT, val); /* Set LED on */
return 0;
};
phys_size_t initdram (int board_type) {
unsigned long junk = 0xa5a59696;
/*
* Note:
* RC = ([(RefreshTime/#rows) / (1/BusClk)] / 16) - 1
*/
#ifdef CONFIG_SYS_FAST_CLK
/*
* Busclk=70MHz, RefreshTime=64ms, #rows=4096 (4K)
* SO=1, NAM=0, COC=0, RTIM=01 (6clk refresh), RC=39
*/
mbar_writeShort(MCFSIM_DCR, 0x8239);
#elif CONFIG_SYS_PLL_BYPASS
/*
* Busclk=5.6448MHz, RefreshTime=64ms, #rows=8192 (8K)
* SO=1, NAM=0, COC=0, RTIM=01 (6clk refresh), RC=02
*/
mbar_writeShort(MCFSIM_DCR, 0x8202);
#else
/*
* Busclk=36MHz, RefreshTime=64ms, #rows=4096 (4K)
* SO=1, NAM=0, COC=0, RTIM=01 (6clk refresh), RC=22 (562 bus clock cycles)
*/
mbar_writeShort(MCFSIM_DCR, 0x8222);
#endif
/*
* SDRAM starts at 0x0000_0000, CASL=10, CBM=010, PS=10 (16bit port),
* PM=1 (continuous page mode)
*/
/* RE=0 (keep auto-refresh disabled while setting up registers) */
mbar_writeLong(MCFSIM_DACR0, 0x00003324);
/* BAM=007c (bits 22,21 are bank selects; 256kB blocks) */
mbar_writeLong(MCFSIM_DMR0, 0x01fc0001);
/** Precharge sequence **/
mbar_writeLong(MCFSIM_DACR0, 0x0000332c); /* Set DACR0[IP] (bit 3) */
*((volatile unsigned long *) 0x00) = junk; /* write to a memory location to init. precharge */
udelay(0x10); /* Allow several Precharge cycles */
/** Refresh Sequence **/
mbar_writeLong(MCFSIM_DACR0, 0x0000b324); /* Enable the refresh bit, DACR0[RE] (bit 15) */
udelay(0x7d0); /* Allow gobs of refresh cycles */
/** Mode Register initialization **/
mbar_writeLong(MCFSIM_DACR0, 0x0000b364); /* Enable DACR0[IMRS] (bit 6); RE remains enabled */
*((volatile unsigned long *) 0x800) = junk; /* Access RAM to initialize the mode register */
return CONFIG_SYS_SDRAM_SIZE * 1024 * 1024;
};
int testdram (void) {
/* TODO: XXX XXX XXX */
printf ("DRAM test not implemented!\n");
return (0);
}