cpu/x86/64bit: Generate static page tables from an assembly file
This removes the need for a tool to generate simple identity pages.
Future patches will link this page table directly into the stages on
some platforms so having an assembly file makes a lot of sense.
This also optimizes the size of the page of each 4K page by placing
the PDPE_table below the PDE.
Change-Id: Ia1e31b701a2584268c85d327bf139953213899e3
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63725
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
diff --git a/src/cpu/x86/64bit/Makefile.inc b/src/cpu/x86/64bit/Makefile.inc
index 721e620..1895498 100644
--- a/src/cpu/x86/64bit/Makefile.inc
+++ b/src/cpu/x86/64bit/Makefile.inc
@@ -5,3 +5,15 @@
romstage-y += mode_switch.S
postcar-y += mode_switch.S
ramstage-y += mode_switch.S
+
+# Add --defsym=_start=0 to suppress a linker warning.
+$(objcbfs)/pt: $(dir)/pt.S
+ $(CC_bootblock) $(CFLAGS_bootblock) $(CPPFLAGS_bootblock) -o $@.tmp $< -Wl,--section-start=.rodata=$(CONFIG_ARCH_X86_64_PGTBL_LOC),--defsym=_start=0
+ $(OBJCOPY_ramstage) -Obinary -j .rodata $@.tmp $@
+ rm $@.tmp
+
+cbfs-files-y += pagetables
+pagetables-file := $(objcbfs)/pt
+pagetables-type := raw
+pagetables-compression := none
+pagetables-COREBOOT-position := $(CONFIG_ARCH_X86_64_PGTBL_LOC)