On Tue, Jun 11, 2002 at 12:21:19PM -0700, Tim Lai wrote: > > Hi, I am new to linux and trying to get some help from > some linux experts out here. I've been reading and > searching the mail list archive for the past few > weeks. > Here is what I have so far: > > I have a ppc750 broad with vxWorks bootrom. I do not > have any device to reflash the broad. I read one of > the mail archive that someone write a program to > work with vxWorks bootrom. And this is what I want > to do. I plan to convert the vmlinux image to asm and > put it in the .text section of another elf file. > Load this elf file and relocate the vmlinux image to > 0xC000000. Is this a feasible approach? > > After the vxWorks bootrom come up, the BAT setting is > phy = virt. The board has 8Meg of RAM. Knowing the > linux kernel need to be at 0xC000000, should I change > the BAT setting to map 7-8M to 0xC0000000, then > copy the image to 0xC0000000? > > I am a little confuse about the MMU in linux. Here is > what I understand: > after the bootrom, the CPU MMU should be phy = virt > after linux booted, linux MMU takes over, and kernel > space is 0xc0000000, and user space is 0x0 to > 0xc0000000. What happened in between? Who is > responible for doing the mapping?
However you want to do it, get the vmlinux located at physical 0 and set r3-r7 as documented in head.S Read head.S and you will see that it takes care of (with some outside calls) all core MMU init for Linux. Regards, -- Matt Porter porter at cox.net This is Linux Country. On a quiet night, you can hear Windows reboot. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
