Hi Ame, > So maybe I need to clarify some more. The PPC460 data sheet > is not too clear on this yet. However, here are my thoughts > on this. Lets just take the simple case as an example. We > have a plurality of 460s where a single one is the master. > Between the master and all the slaves is a PCI bridge. The > slaves are hardwired to boot from pci bus memory -- according > to the datasheet that is at a fixed address. So there does > not appear to be any need to do anything to the slave upon > power up.
Really? I didn't see a comment about the fixed address when I parsed the data sheet. Where is that comment in PP460EX_DS2063.pdf, rev 1.09 April 14, 2008? > Now the master boots and then allocates a chunk > of contiguous memory using a kernel driver or whatever is > needed. The image is just whatever the flash image would > normally contain (uboot + kernel + rootfs). Or you could just have a u-boot image, and then use u-boot to fetch the kernel and rootfs. > The address of that chunk is then given to the pci bridge > so that it can perform inbound translation from the address > that the PPC slaves will use to the address where the image > is physically located. Then the slaves are taken out of reset > and begin reading "flash" across the pci bus which really goes > through the bridge and is mapped to the DRAM on the master (or I > guess it could be the flash on the master, but DRAM seemed > easier since it is already running). > > Ok, so how many holes does this approach have? This seems reasonable to me. However, without the full users manual for the 460EX, and the users manual for the pci bridge, I can't really comment more. Cheers, Dave ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ U-Boot-Users mailing list U-Boot-Users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/u-boot-users
