Ian Campbell
2013-Aug-30 10:52 UTC
[PATCH] xen: arm: describe Xen boot protocol requirements
Signed-off-by: Ian Campbell <ian.campbell@citrix.com> --- docs/misc/arm/booting.txt | 30 ++++++++++++++++++++++++++++++ 1 files changed, 30 insertions(+), 0 deletions(-) create mode 100644 docs/misc/arm/booting.txt diff --git a/docs/misc/arm/booting.txt b/docs/misc/arm/booting.txt new file mode 100644 index 0000000..9802e5e --- /dev/null +++ b/docs/misc/arm/booting.txt @@ -0,0 +1,30 @@ +Booting Xen +==========+ +Xen follows the zImage protocol defined for 32-bit ARM Linux[1] and the +Image protocol defined for ARM64 Linux[2]. + +In both cases the recommendation to boot in HYP/EL2 mode is a strict +requirement for Xen. + +The exceptions to this on 32-bit ARM are as follows: + + Xen does not require the machine type to be passed in r1. This + register is ignored (so may be invalid or the actual machine type). + + Xen does not support the ATAG list and requires Device + Tree. Therefore r2 must point to the physical address of device tree + block (dtb) in system RAM. + + NOTE: although Xen uses the zImage protocol there is no compression + actually used. This should be transparent to the bootloader. The + zImage protocol should still be used and not the stricter "raw + (non-zImage)" protocol described in arm/Booting. + +There are no exception on 64-bit ARM. + +[1] linux/Documentation/arm/Booting +Latest version: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/arm/Booting + +[2] linux/Documentation/arm64/booting.txt +Latest version: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/arm64/booting.txt -- 1.7.2.5