[S] Change in coreboot[master]: Makefile.inc: Support FILENAME-REGION-compression CBFS flag

[Jérémy Compostella (Code Review)]

Attention is currently required from: Martin L Roth.

Jérémy Compostella has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/77230?usp=email )

Change subject: Makefile.inc: Support FILENAME-REGION-compression CBFS flag
......................................................................

Makefile.inc: Support FILENAME-REGION-compression CBFS flag

The `FILENAME-REGION-compression' CBFS flag allows to specify a
compression algorithm per REGION.  Similarily, to `-align' or
`-position', it overrides the `FILENAME-compression' flag for a
particular `REGION'.

It can be use to set the compression to `none' for a particular region
in which the file is going to be use in pre-memory stages and
therefore cannot be uncompressed without alterating the more desired
compressed version for other regions.

BUG=b:279173035
TEST=Verified that with `vtb.bin-COREBOOT-compression := none' the
     vbt.bin in the COREBOOT region is not compressed.

Change-Id: I4e3b827407aeca60f27270ee5d3fa606047a80d5
Signed-off-by: Jeremy Compostella 
---
M Documentation/getting_started/build_system.md
M Makefile.inc
2 files changed, 17 insertions(+), 10 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/30/77230/1

diff --git a/Documentation/getting_started/build_system.md b/Documentation/getting_started/build_system.md
index 787c833..7f19bbe 100644
--- a/Documentation/getting_started/build_system.md
+++ b/Documentation/getting_started/build_system.md
@@ -71,8 +71,9 @@
 Since FMAP policies depend on features using FMAP, that's kept separate from
 the cbfs-files class.

-The `position` and `align` options for file `foo` can be overwritten for a
-region `REGION` using `foo-REGION-position` and `foo-REGION-align`.
+The `position`, `align` and `compression` options for file `foo` can be
+overwritten for a region `REGION` using `foo-REGION-position`,
+`foo-REGION-align` and `foo-REGION-compression`.

The regions that each file should end in can be defined by overriding a
 function called `regions-for-file` that's called as
diff --git a/Makefile.inc b/Makefile.inc
index b5665a7..f3371c1 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -957,17 +957,23 @@
 update-file-for-region = \
    $(subst $(spc),*,$(call extract_nth,1,$(1))|$(call extract_nth,2,$(1))|$(call extract_nth,3,$(1))|$(call extract_nth,4,$(1))|$($(call extract_nth,2,$(1))-$(2)-position)|$($(call extract_nth,2,$(1))-$(2)-align)|$(call extract_nth,7,$(1)))

+# $(call update-file-compression-for-region,file string from $(cbfs-files),region name)
+# Update compression according to overrides for region if available
+# Returns the updated file string
+update-file-compression-for-region = $(subst $(spc),*,$(call extract_nth,1,$(1))|$(call extract_nth,2,$(1))|$(call extract_nth,3,$(1))|$(if $($(call extract_nth,2,$(1))-$(2)-compression),$($(call extract_nth,2,$(1))-$(2)-compression),$(call extract_nth,4,$(1)))|$(call extract_nth,5,$(1))|$(call extract_nth,6,$(1))|$(call extract_nth,7,$(1)))
+
 # $(call placed-files-in-region,region name)
 # like all-files-in-region, but updates the files to contain region overrides
-# to position or alignment.
-placed-files-in-region = $(foreach file,$(call all-files-in-region,$(1)), \
-	$(if $($(call extract_nth,2,$(file))-$(1)-position), \
-		$(if $($(call extract_nth,2,$(file))-$(1)-align), \
-			$(error It is not allowed to specify both alignment and position for $(call extract_nth,2,$(file))-$(1))) \
-		$(call update-file-for-region,$(file),$(1)), \
-		$(if $($(call extract_nth,2,$(file))-$(1)-align), \
+# to position, alignment or compression.
+placed-files-in-region = $(foreach file,$(call all-files-in-region,$(1)),\
+	$(call update-file-compression-for-region,$(strip \
+		$(if $($(call extract_nth,2,$(file))-$(1)-position), \
+			$(if $($(call extract_nth,2,$(file))-$(1)-align), \
+				$(error It is not allowed to specify both alignment and position for $(call extract_nth,2,$(file))-$(1))) \
    		$(call update-file-for-region,$(file),$(1)), \
-			$(file))))
+			$(if $($(call extract_nth,2,$(file))-$(1)-align), \
+				$(call update-file-for-region,$(file),$(1)), \
+				$(file)))),$(1)))

# $(call sort-files,subset of $(cbfs-files))
 # reorders the files in the given set to list files at fixed positions first,