commit 1083f3681841f79903c56a31504ce1a00f5e5501
author Juan Yescas <jyescas@google.com> Fri Jul 14 10:42:31 2023 -0700
committer Juan Yescas <jyescas@google.com> Mon Jul 24 13:48:52 2023 -0700
tree 979d7e29b82808b2ffe36533a697ee3f18688fe6
parent 36c619075ee16e2902b6668e88806dd0ae9ca248

16k: core: Add flag to make AOSP page size agnostic

The new boolean flag will be PRODUCT_PAGE_SIZE_AGNOSTIC.

When PRODUCT_PAGE_SIZE_AGNOSTIC is true:

- AOSP will use getpagesize() to retrieve the page size.
- The flag `TARGET_MAX_PAGE_SIZE_SUPPORTED` has to be equals to `65536`.
- AOSP will be able to use 4k/16k page size Linux kernels

When PRODUCT_PAGE_SIZE_AGNOSTIC is false:

- AOSP will only support 4k page size kernels.

Test: source build/envsetup.sh
      lunch aosp_raven_64-userdebug
      get_build_var TARGET_PAGE_SIZE_AGNOSTIC
      get_build_var PRODUCT_MAX_PAGE_SIZE_SUPPORTED
      65536

      source build/envsetup.sh
      lunch aosp_raven_64-userdebug
      build/make/core/config.mk:414: error: TARGET_MAX_PAGE_SIZE_SUPPORTED has to be 65536 to support page size agnostic.
      10:32:55 dumpvars failed with: exit status 1

Bug: 289419664
Change-Id: If8fc243a3e2cad77414a53a29805c7b6d349d4dd

core/config.mk

diff --git a/core/config.mk b/core/config.mk
index 55ff6ba..920e457 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -425,6 +425,7 @@
 endif
 
 # Set TARGET_MAX_PAGE_SIZE_SUPPORTED.
+# TARGET_MAX_PAGE_SIZE_SUPPORTED indicates the alignment of the ELF segments.
 ifdef PRODUCT_MAX_PAGE_SIZE_SUPPORTED
   TARGET_MAX_PAGE_SIZE_SUPPORTED := $(PRODUCT_MAX_PAGE_SIZE_SUPPORTED)
 else ifeq ($(strip $(call is-low-mem-device)),true)
@@ -440,6 +441,19 @@
 endif
 .KATI_READONLY := TARGET_MAX_PAGE_SIZE_SUPPORTED
 
+# Boolean variable determining if AOSP is page size agnostic. This means
+# that AOSP can use a kernel configured with 4k/16k/64k PAGE SIZES.
+TARGET_PAGE_SIZE_AGNOSTIC := false
+ifdef PRODUCT_PAGE_SIZE_AGNOSTIC
+  TARGET_PAGE_SIZE_AGNOSTIC := $(PRODUCT_PAGE_SIZE_AGNOSTIC)
+  ifeq ($(TARGET_PAGE_SIZE_AGNOSTIC),true)
+      ifneq ($(TARGET_MAX_PAGE_SIZE_SUPPORTED),65536)
+          $(error TARGET_MAX_PAGE_SIZE_SUPPORTED has to be 65536 to support page size agnostic)
+      endif
+  endif
+endif
+.KATI_READONLY := TARGET_PAGE_SIZE_AGNOSTIC
+
 # Pruned directory options used when using findleaves.py
 # See envsetup.mk for a description of SCAN_EXCLUDE_DIRS
 FIND_LEAVES_EXCLUDES := $(addprefix --prune=, $(SCAN_EXCLUDE_DIRS) .repo .git)