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m68knommu: add uboot commandline argument passing support 

This patch adds m68knommu support for getting the kernel command line
arguments from uboot, including the passing of an initrd image from uboot.

We use this on a 5270/5271 based board, and have used it on the 5271evb
development board.  It is based on a patch found in the linux-2.6-denx
git tree, although that tree seems to have had lots of other changes
since which are not in the main Linus kernel.  I believe this will work
on all coldfires, although other m68knommu might be missing the _init_sp
stuff in head.S as far as I can tell.  I only have the coldfire to
test on.

Signed-off-by: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
This commit is contained in:
Lennart Sorensen 2009-09-18 13:49:36 -04:00 committed by Greg Ungerer
parent b0d22d66fd
commit 588baeac38
3 changed files with 107 additions and 2 deletions
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7
arch/m68knommu/Kconfig
View File

@ -533,6 +533,13 @@ config AVNET
default y
depends on (AVNET5282)
config UBOOT
bool "Support for U-Boot command line parameters"
help
If you say Y here kernel will try to collect command
line parameters from the initial u-boot stack.
default n
config 4KSTACKS
bool "Use 4Kb for kernel stacks instead of 8Kb"
default y

92
arch/m68knommu/kernel/setup.c
View File

@ -29,6 +29,8 @@
#include <linux/bootmem.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/root_dev.h>
#include <asm/setup.h>
#include <asm/irq.h>
@ -52,7 +54,6 @@ void (*mach_reset)(void);
void (*mach_halt)(void);
void (*mach_power_off)(void);
#ifdef CONFIG_M68000
#define CPU "MC68000"
#endif
@ -111,6 +112,69 @@ void (*mach_power_off)(void);
extern int _stext, _etext, _sdata, _edata, _sbss, _ebss, _end;
extern int _ramstart, _ramend;
#if defined(CONFIG_UBOOT)
/*
* parse_uboot_commandline
*
* Copies u-boot commandline arguments and store them in the proper linux
* variables.
*
* Assumes:
* _init_sp global contains the address in the stack pointer when the
* kernel starts (see head.S::_start)
*
* U-Boot calling convention:
* (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
*
* _init_sp can be parsed as such
*
* _init_sp+00 = u-boot cmd after jsr into kernel (skip)
* _init_sp+04 = &kernel board_info (residual data)
* _init_sp+08 = &initrd_start
* _init_sp+12 = &initrd_end
* _init_sp+16 = &cmd_start
* _init_sp+20 = &cmd_end
*
* This also assumes that the memory locations pointed to are still
* unmodified. U-boot places them near the end of external SDRAM.
*
* Argument(s):
* commandp = the linux commandline arg container to fill.
* size = the sizeof commandp.
*
* Returns:
*/
void parse_uboot_commandline(char *commandp, int size)
{
extern unsigned long _init_sp;
unsigned long *sp;
unsigned long uboot_kbd;
unsigned long uboot_initrd_start, uboot_initrd_end;
unsigned long uboot_cmd_start, uboot_cmd_end;
sp = (unsigned long *)_init_sp;
uboot_kbd = sp[1];
uboot_initrd_start = sp[2];
uboot_initrd_end = sp[3];
uboot_cmd_start = sp[4];
uboot_cmd_end = sp[5];
if (uboot_cmd_start && uboot_cmd_end)
strncpy(commandp, (const char *)uboot_cmd_start, size);
#if defined(CONFIG_BLK_DEV_INITRD)
if (uboot_initrd_start && uboot_initrd_end &&
(uboot_initrd_end > uboot_initrd_start)) {
initrd_start = uboot_initrd_start;
initrd_end = uboot_initrd_end;
ROOT_DEV = Root_RAM0;
printk(KERN_INFO "initrd at 0x%lx:0x%lx\n",
initrd_start, initrd_end);
}
#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
}
#endif /* #if defined(CONFIG_UBOOT) */
void __init setup_arch(char **cmdline_p)
{
int bootmap_size;
@ -128,7 +192,24 @@ void __init setup_arch(char **cmdline_p)
#if defined(CONFIG_BOOTPARAM)
strncpy(&command_line[0], CONFIG_BOOTPARAM_STRING, sizeof(command_line));
command_line[sizeof(command_line) - 1] = 0;
#endif
#endif /* CONFIG_BOOTPARAM */
#if defined(CONFIG_UBOOT)
/* CONFIG_UBOOT and CONFIG_BOOTPARAM defined, concatenate cmdline */
#if defined(CONFIG_BOOTPARAM)
/* Add the whitespace separator */
command_line[strlen(CONFIG_BOOTPARAM_STRING)] = ' ';
/* Parse uboot command line into the rest of the buffer */
parse_uboot_commandline(
&command_line[(strlen(CONFIG_BOOTPARAM_STRING)+1)],
(sizeof(command_line) -
(strlen(CONFIG_BOOTPARAM_STRING)+1)));
/* Only CONFIG_UBOOT defined, create cmdline */
#else
parse_uboot_commandline(&command_line[0], sizeof(command_line));
#endif /* CONFIG_BOOTPARAM */
command_line[sizeof(command_line) - 1] = 0;
#endif /* CONFIG_UBOOT */
printk(KERN_INFO "\x0F\r\n\nuClinux/" CPU "\n");
@ -204,6 +285,13 @@ void __init setup_arch(char **cmdline_p)
free_bootmem(memory_start, memory_end - memory_start);
reserve_bootmem(memory_start, bootmap_size, BOOTMEM_DEFAULT);
#if defined(CONFIG_UBOOT) && defined(CONFIG_BLK_DEV_INITRD)
if ((initrd_start > 0) && (initrd_start < initrd_end) &&
(initrd_end < memory_end))
reserve_bootmem(initrd_start, initrd_end - initrd_start,
BOOTMEM_DEFAULT);
#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
/*
* Get kmalloc into gear.
*/

10
arch/m68knommu/platform/coldfire/head.S
View File

@ -106,6 +106,9 @@
.global _ramvec
.global _ramstart
.global _ramend
#if defined(CONFIG_UBOOT)
.global _init_sp
#endif
/*****************************************************************************/
@ -124,6 +127,10 @@ _ramstart:
.long 0
_ramend:
.long 0
#if defined(CONFIG_UBOOT)
_init_sp:
.long 0
#endif
/*****************************************************************************/
@ -137,6 +144,9 @@ __HEAD
_start:
nop /* filler */
movew #0x2700, %sr /* no interrupts */
#if defined(CONFIG_UBOOT)
movel %sp,_init_sp /* save initial stack pointer */
#endif
/*
* Do any platform or board specific setup now. Most boards