[coreboot-gerrit] [XS] Change in coreboot[main]: lib/jpeg: enable dst-pixel-format allowlist

[Nigel Tao (Code Review)]

Nigel Tao has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/84340?usp=email )

Change subject: lib/jpeg: enable dst-pixel-format allowlist
......................................................................

lib/jpeg: enable dst-pixel-format allowlist

Wuffs can decode image files to a variety of pixel formats (BGRA vs
RGBA, premultiplied vs non-premultiplied alpha, 8-bit vs 16-bit, etc).
If Coreboot always decodes to BGRA and never to RGBA then we can cut out
the unused code paths at compile time, via configuration macros.

Before  fallback/ramstage  84180 LZMA (174340 decompressed)
After   fallback/ramstage  83513 LZMA (173056 decompressed) = 99.21%

It's not a large saving, but every little bit helps.

Change-Id: Ie29592f74f245cb890d18b68060640e9bab192b2
---
M src/lib/jpeg.c
1 file changed, 7 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/40/84340/1

diff --git a/src/lib/jpeg.c b/src/lib/jpeg.c
index 617ab0b..2de58b6 100644
--- a/src/lib/jpeg.c
+++ b/src/lib/jpeg.c
@@ -9,6 +9,10 @@
 #include "jpeg.h"

#define WUFFS_CONFIG__AVOID_CPU_ARCH
+#define WUFFS_CONFIG__DST_PIXEL_FORMAT__ENABLE_ALLOWLIST
+#define WUFFS_CONFIG__DST_PIXEL_FORMAT__ALLOW_BGR_565
+#define WUFFS_CONFIG__DST_PIXEL_FORMAT__ALLOW_BGR
+#define WUFFS_CONFIG__DST_PIXEL_FORMAT__ALLOW_BGRA_NONPREMUL
 #define WUFFS_CONFIG__MODULES
 #define WUFFS_CONFIG__MODULE__BASE
 #define WUFFS_CONFIG__MODULE__JPEG
@@ -62,6 +66,9 @@
    	return JPEG_DECODE_FAILED;
    }

+	/* The WUFFS_BASE__PIXEL_FORMAT__FOOBAR values used here match
+	 * "#define WUFFS_CONFIG__DST_PIXEL_FORMAT__ALLOW_FOOBAR" above.
+	 */
    uint32_t pixfmt;
    switch (depth) {
    case 16: