On Mon, Jan 30, 2012 at 10:28 AM, John Williams <john.willi...@petalogix.com> wrote: > 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
And while we're at it how about overriding arbitrary boot PC addresses as well? --boot-addr 0xdeadbeef It should be possible to boot random bootrom code in QEMU without hacking on the machine model. qemu-system-arm -M foo --file bootrom.bin@0x000000 --boot-addr 0x00001000 We bumped into this recently - we need a cleaner way of telling QEMU if it's pretending to be just the machine with some minimal initial state as above(for running bootloaders, baremetal etc), or it's being the machine *plus* a bootloader (booting vmlinux/zimage). Currently it's pretty hacky. John > > -- 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 -- 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
