Re: U-boot and linux command line parameters
From: David Gibson <hidden>
Date: 2009-05-25 00:17:53
On Sun, May 24, 2009 at 02:38:52PM -0700, Mirek23 wrote:
Dear All, I use linux kernel 2.6.23 and u-boot 1.2.0 (on ppc405 virtex-4 ) for some time. All works fine when the kernel together with initramfs is smaller than 8MB. If it is bigger than the kernel does not boot properly. First of all I would like to know how the address for the linux command line parameters is "transferred" from u-boot to linux for ppc405 (virtex4 chip)? (via some registers or is it a fixed address in the memory ie. 8MB?) Does somebody know what should be changed, in the kernel, in order to move this limitation from 8MB to let say 12MB? I would be grateful for any hint.
IIRC, U-boot 1.2.0 is a version of u-boot before it became device tree aware. Which means if I'm reading the cuboot.c code correctly, the command line address is passed to the kernel at entry in r6, with the length in r7. With later, device-tree aware u-boot versions, the command line is instead passed as a device tree property. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson