Dear David, in message <3D062232.3010003 at cray.com> you wrote: > > I'm trying to keep a small trace buffer over re-boots > of linux from ppcboot, so give a mem=31M flag to linux > kernel. Yet by the time linux is up, it has overwritten > that memory anyway.. PPCBOOT is properly leaving it > be (with PRAM feature) and correct arg. goes to kernel..
Let me guess... you boot with a ramdisk image? > After 'reboot' from linux, the memory contents of > the last meg are still valid (in ppcboot) but by the time linux > is back up, the region has been trashed. Why? If you use a ramdisk image, you should read the documentation for the "initrd_high" environment variable in http://www.denx.de/doc/TQM8xxL/ppcboot.html#PPCBOOT-VARIABLES (or in the PPCBoot README). > Help, please. How to prevent linux from talking to > that memory region during bootup? Linux does not use the memory beyond what you tell it with "mem=". Hope this helps... [BTW: your CD is in the mail.] Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de Machines take me by surprise with great frequency. - Alan Turing ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
