PKGBUILDs/alarm/kodi-rpi-git/use-mcpu-avoiding-march-and-mtune.patch

From 2e2417894ac5d35bc3d93b86c18f4df299f4d933 Mon Sep 17 00:00:00 2001
From: graysky <graysky@archlinux.us>
Date: Sat, 12 Dec 2020 09:10:28 -0500
Subject: [PATCH] use -mcpu= avoiding -march and -mtune for armv7h

From what I understand, when building on ARM, it's best to avoid the -march=
flag and rather use -mcpu= flag due to differences in meaning on ARM vs x86[1].
Additionally, this patch avoids thousands of warns like the following when
building for armv7h:
 cc1: warning: switch '-mcpu=cortex-a72' conflicts with '-march=armv8-a'

This is due to the way ffmpeg's configure script defines -march=armv8-a when it
encounters any cortex-a* passed to it.

for reference and to experiment:
untar ffmpeg, run ./configure, then inspect the output of ffbuild/config.mak and adjust:
kodi-build/build/ffmpeg/src/ffmpeg-build/ffmpeg-prefix/src/ffmpeg-build/ffbuild/config.mak

1. https://community.arm.com/developer/tools-software/tools/b/tools-software-ides-blog/posts/compiler-flags-across-architectures-march-mtune-and-mcpu

---
 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index 8569a60..0d3aafb 100755
--- a/configure
+++ b/configure
@@ -4948,7 +4948,7 @@ elif enabled arm; then
 
     case $cpu in
         armv*)
-            cpuflags="-march=$cpu"
+            cpuflags="-mcpu=cortex-a53"
             subarch=$(echo $cpu | sed 's/[^a-z0-9]//g')
         ;;
         *)
-- 
2.29.2