edk2-firmware: Respect RECIPE_SYSROOT

This is particularly useful to make sure the compiler uses the recipe
sysroot for headers avoiding host contaminations like:

| opts-GCC.h:42:
| /usr/include/stdint.h:26:10: fatal error: 'bits/libc-header-start.h'
file not found
| #include <bits/libc-header-start.h>

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-oniro-staging/recipes-bsp/uefi/edk2-firmware/0001-Respect-BUILD_CFLAGS-in-GCC_ALL_CC_FLAGS.patch

+From 35b7765e0e140f45ff25348c81172baca6197f52 Mon Sep 17 00:00:00 2001
+From: Andrei Gherzan <andrei.gherzan@huawei.com>
+Date: Fri, 12 Aug 2022 00:23:37 +0200
+Subject: [PATCH] Respect BUILD_CFLAGS in GCC_ALL_CC_FLAGS
+
+Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>
+Upstream-Status: Inappropriate [OE specific]
+---
+ BaseTools/Conf/tools_def.template | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
+index f2bb6247e8..e19d34214f 100755
+--- a/BaseTools/Conf/tools_def.template
++++ b/BaseTools/Conf/tools_def.template
+@@ -1867,7 +1867,7 @@ NOOPT_*_*_OBJCOPY_ADDDEBUGFLAG     = --add-gnu-debuglink=$(DEBUG_DIR)/$(MODULE_N
+ *_*_*_DTCPP_PATH                   = DEF(DTCPP_BIN)
+ *_*_*_DTC_PATH                     = DEF(DTC_BIN)
+ 
+-DEFINE GCC_ALL_CC_FLAGS            = -g -Os -fshort-wchar -fno-builtin -fno-strict-aliasing -Wall -Werror -Wno-array-bounds -include AutoGen.h -fno-common
++DEFINE GCC_ALL_CC_FLAGS            = -g -Os -fshort-wchar -fno-builtin -fno-strict-aliasing -Wall -Werror -Wno-array-bounds -include AutoGen.h -fno-common --sysroot=ENV(TARGET_SYSROOT)
+ DEFINE GCC_IA32_CC_FLAGS           = DEF(GCC_ALL_CC_FLAGS) -m32 -malign-double -freorder-blocks -freorder-blocks-and-partition -O2 -mno-stack-arg-probe
+ DEFINE GCC_X64_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) -mno-red-zone -Wno-address -mno-stack-arg-probe
+ DEFINE GCC_ARM_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) -mlittle-endian -mabi=aapcs -fno-short-enums -funsigned-char -ffunction-sections -fdata-sections -fomit-frame-pointer -Wno-address -mthumb -mfloat-abi=soft -fno-pic -fno-pie
+-- 
+2.25.1
+

meta-oniro-staging/recipes-bsp/uefi/edk2-firmware_%.bbappend

@@ -2,9 +2,18 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+FILESEXTRAPATHS:prepend := "${THISDIR}/${BPN}:"
+SRC_URI += " \
+	file://0001-Respect-BUILD_CFLAGS-in-GCC_ALL_CC_FLAGS.patch \
+"
+
 export GCC5_ARM_PREFIX = "${TARGET_PREFIX}"
 export CLANG38_ARM_PREFIX = "${TARGET_PREFIX}"
 
+# This is passed in the 0001-Respect-BUILD_CFLAGS-in-GCC_ALL_CC_FLAGS.patch
+# patch so that the build can find the right headers in the sysroot.
+export TARGET_SYSROOT = "${RECIPE_SYSROOT}"
+
 EDK2_BUILD_RELEASE:toolchain-clang = "1"
 
 do_configure:prepend() {