> > Normally is it the uboot that uncompresses the kernel or the kernel > uncompress itself? > > >>How would something compressed uncompress itself? If u-boot is being > used > >>it will uncompress a compressed kernel and put the image at physical > 0. > > Small correction. Just like a self extracting binary, a kernel can have > a decompression code prepended to the start of kernel which can > decompress the > Kernel. This is how redboot for xscale is structured or syslinux /lilo > for x86.
This also happens with the boot wrapper that is in arch/{ppc,powerpc}/boot > > Although u-boot has simplified this step by doing the CRC checksum of > the > uiMage header as well as data and also decompress the kernel. Based on > load > address, entry point, the kernel can start executing. > > Now, whether cache is enable or not, MMU is enabled/disabled depends on > the > Developer. In current u-boot, the MMU is not used. I-Cache is On and > D-cache > is off. I'm not sure what sub-arch we are talking about, but some do have the MMU on. - kumar