On Tue, Feb 18, 2014 at 10:09:10AM -0600, Dennis Gilmore wrote:
I'm putting what I have for the documentation so far at the end of this email. I think that soc families should have a common settings file, each board should have its on file and then we have a common set of configurations on how to boot.
For the next round, please put this into doc/ as part of the first patch. Thanks!
[snip]
fdt_addr_r: Mandatory, This is the location where the sysboot/pxeboot with load the dtb to, using the fdtdir/devicetreedir or fdt/devicetree options in the pxe/extlinux config file. The location can be anywhere in ram it just needs to not overlap with anything, allowing 1 megabyte seems to be a safe option.
ramdisk_addr_r: Mandatory, This is the location where the sysboot/pxeboot with load the initramfs to, using the initrd option in the pxe/extlinux config file, the location of the initramfs does not matter, there needs to be enough room to be able to store any image. Making the image the last item stored should allow for any initramfs to fit and not overwrite anything else.
kernel_addr_r: Mandatory,
pxe_addr_r: Mandatory, used by the PXE code to hold the pxelinux config file. The location can be anywhere in ram it just needs to not overlap with anything, allowing 1 megabyte seems to be a safe option.
scriptaddr: Mandatory,
suggested mapping: 16M
We need to talk much more about the suggested mapping as there's a few hard requirements that must be obeyed. The device tree _must_ be placed within kernel accessible low mem and not overwritten by zImage decompression. A reference to Documentation/arm/Booting in the kernel would also be helpful and then summarize saying kernel_addr_r should be above 32MiB and below 128MiB from the base of system ram.