On Wed, Apr 25, 2001 at 06:38:03PM +0200, Shoudong Xu wrote:
>
> Hi,
>
> I try to run linuxppc_2_5 (ramdisk size = 4096KB and initrd supported) with a
> root fs (build by myself) on a Force powerCore 6750 board with the following
> configuration : root =/dev/ram
> Here , I can not pass commond string the kernel , so I have to modify the
> file arch/ppc/kernel/setup.c direct
> - sprintf(cmd_line,/*"nfsroot=10.0.0.69:/opt/hardhat/devkit/ppc/4xx/target
> */"ip=autoconf");
> + sprintf(cmd_line,"root=/dev/ram")
> Then make zImage.initrd to get a kernel image -- zImage.initrd.pcore and I
> burn it to user_flash1
<snip>
> Questions:
> 1)Why can't linux mount the root filessystem? How to mount ?
You need to apply the following patch (the second hunk actually fixes
the bug):
diff -u -r1.14 pcore_setup.c
--- pcore_setup.c 2001/03/30 02:41:29 1.14
+++ pcore_setup.c 2001/05/01 15:31:29
@@ -116,10 +116,15 @@
/* Lookup PCI host bridges */
board_type = pcore_find_bridges();
+#ifdef CONFIG_BLK_DEV_INITRD
+ if (initrd_start)
+ ROOT_DEV = MKDEV(RAMDISK_MAJOR, 0); /* /dev/ram */
+ else
+#endif
#ifdef CONFIG_ROOT_NFS
- ROOT_DEV = to_kdev_t(0x00ff); /* /dev/nfs pseudo device */
+ ROOT_DEV = to_kdev_t(0x00ff); /* /dev/nfs pseudo device */
#else
- ROOT_DEV = to_kdev_t(0x0802); /* /dev/sda2 */
+ ROOT_DEV = to_kdev_t(0x0802); /* /dev/sda2 */
#endif
}
@@ -216,6 +221,14 @@
pcore_init(unsigned long r3, unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7)
{
+#ifdef CONFIG_BLK_DEV_INITRD
+ if ( r4 )
+ {
+ initrd_start = r4 + KERNELBASE;
+ initrd_end = r5 + KERNELBASE;
+ }
+#endif
+
/* Copy cmd_line parameters */
if ( r6)
{
> 2)Can linux mount the flash as it's root filesystem direct?
Sure, just enable MTD/block/ffs support and provide a driver for your'
flash device if not supported.
--
Matt Porter
MontaVista Software, Inc.
mporter at mvista.com
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