Fix the CI jobs that fail on the Ubuntu 26.04 runner image

.github/workflows/test-endian.yml

@@ -25,9 +25,14 @@ jobs:
         run: |
           export DEBIAN_FRONTEND=noninteractive
           sudo apt-get update -o Acquire::Retries=3
+          # Ubuntu 26.04 dropped qemu-user-static: qemu-user carries the
+          # static emulators there, as qemu-ppc.
+          QEMU_PKG=qemu-user-static
+          apt-cache policy "$QEMU_PKG" | grep -q 'Candidate: [0-9]' \
+            || QEMU_PKG=qemu-user
           sudo apt-get install --no-install-recommends -y -q \
             -o Acquire::Retries=3 \
-            gcc-powerpc-linux-gnu libc6-dev-powerpc-cross qemu-user-static \
+            gcc-powerpc-linux-gnu libc6-dev-powerpc-cross "$QEMU_PKG" \
             dosfstools mtools e2fsprogs
 
       # Fixture generation takes minutes, so prove the cross toolchain works
@@ -39,8 +44,9 @@ jobs:
           powerpc-linux-gnu-gcc -static -o /tmp/be_probe /tmp/be_probe.c
           file /tmp/be_probe | grep -q 'MSB' \
             || { echo "cross-compiler did not produce a big-endian binary"; exit 1; }
-          qemu-ppc-static /tmp/be_probe \
-            || { echo "qemu-ppc-static cannot run a big-endian binary"; exit 1; }
+          QEMU_PPC=$(command -v qemu-ppc-static || command -v qemu-ppc)
+          "$QEMU_PPC" /tmp/be_probe \
+            || { echo "$QEMU_PPC cannot run a big-endian binary"; exit 1; }
           echo "big-endian toolchain OK"
 
       - name: generate filesystem fixtures

.github/workflows/test-sbom.yml

@@ -43,7 +43,12 @@ on:
 
 jobs:
   sbom_canary:
-    runs-on: ubuntu-latest
+    # Held on 24.04: the macro capture runs each compiler at its own default
+    # language standard, and from GCC 15 that default is C23, which defines
+    # macros (the <stdint.h> *_WIDTH family) that clang's default does not.
+    # The neutrality check below then fails on 26.04 until the capture pins a
+    # standard.
+    runs-on: ubuntu-24.04
     timeout-minutes: 20
 
     steps:

.github/workflows/test-x86-fsp-qemu.yml

@@ -45,7 +45,7 @@ jobs:
         run: |
           export DEBIAN_FRONTEND=noninteractive
           sudo apt-get update -o Acquire::Retries=3
-          sudo apt-get install --no-install-recommends -y -q -o Acquire::Retries=3 nasm gcc-multilib qemu-system-x86 swtpm uuid-dev
+          sudo apt-get install --no-install-recommends -y -q -o Acquire::Retries=3 nasm gcc-multilib qemu-system-x86 swtpm uuid-dev python3-setuptools
       - name: run test
         run: |
           ./tools/scripts/x86_fsp/qemu/test_qemu.sh
@@ -65,7 +65,7 @@ jobs:
         run: |
           export DEBIAN_FRONTEND=noninteractive
           sudo apt-get update -o Acquire::Retries=3
-          sudo apt-get install --no-install-recommends -y -q -o Acquire::Retries=3 nasm gcc-multilib qemu-system-x86 uuid-dev dosfstools mtools e2fsprogs
+          sudo apt-get install --no-install-recommends -y -q -o Acquire::Retries=3 nasm gcc-multilib qemu-system-x86 uuid-dev python3-setuptools dosfstools mtools e2fsprogs
       - name: run test
         run: |
           ./tools/scripts/x86_fsp/qemu/test_qemu.sh -f
@@ -84,7 +84,7 @@ jobs:
         run: |
           export DEBIAN_FRONTEND=noninteractive
           sudo apt-get update -o Acquire::Retries=3
-          sudo apt-get install --no-install-recommends -y -q -o Acquire::Retries=3 nasm gcc-multilib qemu-system-x86 swtpm uuid-dev
+          sudo apt-get install --no-install-recommends -y -q -o Acquire::Retries=3 nasm gcc-multilib qemu-system-x86 swtpm uuid-dev python3-setuptools
       - name: run test
         run: |
           ./tools/scripts/x86_fsp/qemu/test_qemu.sh -r

arch.mk

@@ -2609,6 +2609,10 @@ endif
 # x86-64 FSP targets
 ifeq ("${FSP}", "1")
   CFLAGS+=-DWOLFBOOT_FSP=1
+  # State the baseline CPU. A distribution compiler can default to a newer
+  # level (Ubuntu's amd64v3 variant targets x86-64-v3), and the BMI2-class
+  # instructions it then emits fault on a CPU, real or emulated, without them.
+  CFLAGS+=-march=x86-64
   USE_GCC_HEADLESS=0
   LD_START_GROUP =
   LD_END_GROUP =

src/string.c

@@ -257,6 +257,11 @@ int memcmp(const void *_s1, const void *_s2, size_t n)
     return diff;
 }
 
+/* A C23 <string.h> defines memchr as a macro that keeps the constness of
+ * its argument; this is the function itself. */
+#ifdef memchr
+#undef memchr
+#endif
 void* memchr(void const *s, int c_in, size_t n)
 {
     unsigned char c = (unsigned char)c_in;

tools/fs-test/README.md

@@ -82,7 +82,7 @@ Two notes on the fixtures:
 
 ## Big-endian coverage
 
-`make check` also runs the fixtures as **big-endian PowerPC** under `qemu-user`, when `powerpc-linux-gnu-gcc` and `qemu-ppc-static` are installed. It skips with a note otherwise.
+`make check` also runs the fixtures as **big-endian PowerPC** under `qemu-user`, when `powerpc-linux-gnu-gcc` and `qemu-ppc-static` (or `qemu-ppc`, on distributions whose `qemu-user` package replaced `qemu-user-static`) are installed. It skips with a note otherwise.
 
 This matters because the parsers read every multi-byte on-media field through byte-wise accessors (`fs_le16` / `fs_le32`) rather than casting a buffer to a struct. That should make them endian-neutral, and the big-endian run proves it instead of assuming it.
 

tools/fs-test/runtests.sh

@@ -65,8 +65,11 @@ neg ext4-4k.img       0 "/a/b/c/d/e/f/g/h/i/j/k/l.itb" "path too deep"
 # entries, and every FAT32/ext4 field. All of it is read byte-wise, so the
 # whole stack should be endian-neutral. Prove it by running the same
 # fixtures as big-endian PowerPC under qemu-user.
+# The emulator is qemu-ppc-static where the qemu-user-static package exists,
+# and qemu-ppc from qemu-user on distributions that dropped it.
+QEMU_PPC=$(command -v qemu-ppc-static || command -v qemu-ppc || true)
 if command -v powerpc-linux-gnu-gcc >/dev/null 2>&1 && \
-   command -v qemu-ppc-static >/dev/null 2>&1; then
+   [ -n "$QEMU_PPC" ]; then
     echo
     echo "=== big-endian (PowerPC), full stack incl. MBR/GPT ==="
     # Do NOT hide this build. A cross-compile failure here (a missing
@@ -86,7 +89,7 @@ if command -v powerpc-linux-gnu-gcc >/dev/null 2>&1 && \
         local img="$1" path="$2"
         [ -f "$F/$img" ] || return
         printf "  %-26s " "$img"
-        if qemu-ppc-static ./fs-test-be verify "$F/$img" 0 "$path" \
+        if "$QEMU_PPC" ./fs-test-be verify "$F/$img" 0 "$path" \
                 "$F/payload/os.itb" >/dev/null 2>&1; then
             echo "PASS"; pass=$((pass + 1))
         else
@@ -102,7 +105,7 @@ if command -v powerpc-linux-gnu-gcc >/dev/null 2>&1 && \
     fi
 else
     echo
-    echo "  (big-endian check skipped: needs powerpc-linux-gnu-gcc + qemu-ppc-static)"
+    echo "  (big-endian check skipped: needs powerpc-linux-gnu-gcc + qemu-ppc-static or qemu-ppc)"
 fi
 
 echo

tools/scripts/x86_fsp/qemu/qemu_build_fsp.sh

@@ -59,6 +59,9 @@ download_sbl_patch_and_patch_edkii() {
 }
 
 build_qemu_fsp() {
+    # This EDK2 release's host tools are pre-C23 code (old-style function
+    # declarations), and C23 is the default from GCC 15.
+    export BUILD_CC="${BUILD_CC:-gcc -std=gnu17}"
     (cd "$WORK_DIR/edk2" &&
          python ./BuildFsp.py &&
          cd BuildFsp &&