the following patch was just integrated into master: commit 623368113c7fb0a7382cb28ecfba5384cd4f12a0 Author: Julius Werner jwerner@chromium.org Date: Mon May 18 13:11:12 2015 -0700
arm64: Decouple MMU functions from memranges
The current arm64 MMU interface is difficult to use in pre-RAM environments. It is based on the memranges API which makes use of malloc(), and early stages usually don't have a heap. It is also built as a one-shot interface that requires all memory ranges to be laid out beforehand, which is a problem when existing areas need to change (e.g. after initializing DRAM).
The long-term goal of this patch is to completely switch to a configure-as-you-go interface based on the mmu_config_range() function, similar to what ARM32 does. As a first step this feature is added side-by-side to the existing interface so that existing SoC implementations continue to work and can be slowly ported over one by one. Like the ARM32 version it does not garbage collect page tables that become unused, so repeated mapping at different granularities will exhaust the available table space (this is presumed to be a reasonable limitation for a firmware environment and keeps the code much simpler).
Also do some cleanup, align comments between coreboot and libpayload for easier diffing, and change all error cases to assert()s. Right now the code just propagates error codes up the stack until it eventually reaches a function that doesn't check them anymore. MMU configuration errors (essentially just misaligned requests and running out of table space) should always be compile-time programming errors, so failing hard and fast seems like the best way to deal with them.
BRANCH=None BUG=None TEST=Compile-tested rush_ryu. Booted on Oak and hacked MMU init to use mmu_config_range() insted of memranges. Confirmed that CRCs over all page tables before and after the change are equal.
Change-Id: I93585b44a277c1d96d31ee9c3dd2522b5e10085b Signed-off-by: Patrick Georgi pgeorgi@chromium.org Original-Commit-Id: f10fcba107aba1f3ea239471cb5a4f9239809539 Original-Change-Id: I6a2a11e3b94e6ae9e1553871f0cccd3b556b3e65 Original-Signed-off-by: Julius Werner jwerner@chromium.org Original-Reviewed-on: https://chromium-review.googlesource.com/271991 Original-Reviewed-by: Aaron Durbin adurbin@chromium.org Reviewed-on: http://review.coreboot.org/10304 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel paulepanter@users.sourceforge.net Reviewed-by: Stefan Reinauer stefan.reinauer@coreboot.org
See http://review.coreboot.org/10304 for details.
-gerrit