On Sun, Jan 29, 2012 at 4:51 PM, Peter Crosthwaite <peter.crosthwa...@petalogix.com> wrote: > Hi All, > > So on the topic of these command line arguments for initrd, dtb and friends, > another related issue we have encountered (and have hacked around in our > tree) is not being able to relocate the initrd or kernel. Currently these > memory locations are hardcoded in arm_boot.c: > > #define KERNEL_ARGS_ADDR 0x100 > #define KERNEL_LOAD_ADDR 0x00010000 > #define INITRD_LOAD_ADDR 0x00d00000 > > If you see patch 6/7 in this same series I put in place a hack to override > the initrd location in memory, but I wonder if instead this should go up to > the command line interface as a parameter. Currently the machine model (or > arm_boot.c) defines exactly where kernels/initrds/command-line-args line in > memory, but since these are software properties should perhaps they go up to > the command line as -kernel,foo=bar options? E.G: > > qemu-system-arm > -kernel,kernel-image=/foo/zImage,kernel-addr=0x00010000,initrd=/foo/initrd,initrd_addr=0x00d00000
There's an opportunity here - QEMU needs the cmdline ability to load random binaries/elfs anyway, such as --load file@address e.g. --load image.bin@0xa4000000 -- load file.elf (no address required) This option or one like it would make it much easier and less hard-coded to assemble any sort of initial memory state. Extending this, kernels, initrds and DTBs all can have machine-specific preferred addresses but can be overriden in the same way: --kernel zImage@0x20000000 --initrd fs.img@0x40000000 and so on The '@' symbol will need to be escaped by it's a pretty natural syntax. John -- John Williams, PhD, B. Eng, B. IT PetaLogix - Linux Solutions for a Reconfigurable World w: www.petalogix.com p: +61-7-30090663 f: +61-7-30090663
