On Tue, 2 Nov 2010 10:17:23 +0100 Stefan Roese <s...@denx.de> wrote: > Hi Heiko, > > On Tuesday 02 November 2010 09:55:46 Heiko Schocher wrote: > > >> - preloader copies first page of nand (nand_spl code) to > > >> > > >> 0xbb000000 (some cpu internal mem) and jumps to this address > > >> > > >> - nand_spl does lowlevelinit, relocate itself to TEXT_BASE (nand_spl > > >> code) > > > > > > Why is this relocation needed? I understand that this 0xbb000000 > > > > Thats the question to solve ... don;t know, why nand_spl code > > on arm (and other architectures?) do this ... I try to have a look > > to find out, if we can run the nand_spl code complete from > > this address, and immedietaly copy u-boot from nand to ram ... > > On PPC4xx we need to copy the code from the original location (4KiB loaded > via > the ROM IPL boot loader) to SDRAM and continue running it from there. This is > necessary since we can't run from the original location (0xfffffxxx) and use > the PPC4xx NAND controller at the same time.
We have the same restriction on FSL NAND controllers -- certainly the eLBC, and I think also the NFC which is used on ARM, though I'm less familiar with that one. > So there is no relocation to TEXT_BASE on 4xx but "only" a copy to > CONFIG_SYS_NAND_BOOT_SPL_DST. It looks like you do memory init from assembly code to pull that off. On 83xx/85xx we do an actual relocation of the NAND SPL. Not sure about ARM. -Scott _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
