Add prerequisite support for macOS

.github/workflows/macos.yml

@@ -0,0 +1,118 @@
+name: macOS
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+jobs:
+  build:
+    strategy:
+      matrix:
+        runner:
+          - macos-latest
+        ocaml-compiler:
+          - 5.5.0
+    name: >-
+      OCaml ${{ matrix.ocaml-compiler }}, macOS arm64
+    runs-on: ${{ matrix.runner }}
+    steps:
+    - uses: actions/checkout@v7
+    - uses: ocaml/setup-ocaml@v3
+      with:
+        ocaml-compiler: ${{ matrix.ocaml-compiler }}
+        opam-local-packages:
+    - name: Install opam packages
+      run: |
+        opam install dune ocamlfind ocaml-src opatch opam-installer
+    - name: Check out Solo5
+      uses: actions/checkout@v7
+      with:
+        repository: shym/solo5
+        ref: macos
+        path: solo5
+    - name: Install dependencies
+      run: brew install llvm lld
+    - name: Build and install Solo5
+      run: |
+        set -x
+        cd solo5
+        ./configure.sh --prefix="$(opam var prefix)" --disable-elftool \
+          --path-prepend="$(brew --prefix llvm)/bin:$(brew --prefix lld)/bin:"
+        make -j2
+        make install
+    - name: Build OCaml/Solo5
+      run: |
+        set -x
+        eval $(opam env)
+        pfx="$(opam var prefix)"
+        ./configure.sh --prefix="$pfx" \
+          --sysroot="$pfx/lib/ocaml-solo5" \
+          --target=aarch64-solo5-none-static \
+          --othertoolprefix=llvm- \
+          --ocaml-configure-option=--disable-function-sections \
+          --path-prepend="$(brew --prefix llvm)/bin:$(brew --prefix lld)/bin:"
+        make V=1 -j2
+        make install
+    - name: Show the toolchain configuration
+      run: |
+        set -x
+        opam exec -- ocamlfind -toolchain solo5 opt -config
+        opam exec -- ocamlfind -toolchain solo5 printconf
+        opam exec -- ocamlfind -toolchain solo5 list
+
+    # Do not build all the examples as hello is trying to link against an
+    # external fmt library and the opam-installed fmt is incompatible with the
+    # OCaml/Solo5 Stdlib (inconsistent assumptions...)
+    - name: Compile examples with hvt
+      run: |
+        MODE=hvt opam exec -- dune build --root example --display short \
+          config.exe sysfail.exe
+    - name: Compile examples with spt
+      run: |
+        MODE=spt opam exec -- dune build --root example --display short \
+          config.exe sysfail.exe
+    - name: Build an artifact of the spt executables
+      run: |
+        set -x
+        for e in config sysfail; do \
+          cp example/_build/solo5/$e.exe /tmp/$e.spt ; \
+        done
+        cd /tmp
+        tar caf unikernels.tar.zst *.spt
+    - name: Upload artifact
+      uses: actions/upload-artifact@v7
+      with:
+        name: unikernels
+        path: /tmp/unikernels.tar.zst
+        retention-days: 1
+
+  run:
+    name: Run unikernels
+    needs: build
+    runs-on: ubuntu-24.04-arm
+    steps:
+    - name: Install dependencies
+      run: |
+        sudo apt-get install -y libseccomp-dev pkg-config
+    - name: Check out Solo5
+      uses: actions/checkout@v7
+      with:
+        repository: solo5/solo5
+        ref: v0.12.0
+        path: solo5
+    - name: Build Solo5 tenders
+      run: |
+        set -x
+        cd solo5
+        ./configure.sh --disable-toolchain
+        make -j3
+    - name: Download artifact
+      uses: actions/download-artifact@v8
+      with:
+        name: unikernels
+    - name: Run the spt unikernels
+      run: |
+        set -x
+        tar xaf unikernels.tar.zst
+        solo5/tenders/spt/solo5-spt config.spt
+        ! solo5/tenders/spt/solo5-spt sysfail.spt

.github/workflows/test.yml

@@ -17,7 +17,7 @@ jobs:
           - runner: ubuntu-latest
             ocaml-compiler: 5.4.1
     name: >-
-      OCaml ${{ matrix.ocaml-compiler }}
+      OCaml ${{ matrix.ocaml-compiler }}, Linux
       ${{ case(matrix.runner=='ubuntu-latest', 'x86_64', 'arm64') }}
     runs-on: ${{ matrix.runner }}
     steps:

Makefile

@@ -26,8 +26,11 @@ nolibc/libnolibc.a: phony-nolibc
 
 .PHONY: phony-nolibc
 phony-nolibc:
-	$(MAKE) -C nolibc libnolibc.a \
+	+env PATH="$(MAKECONF_PATH_PREPEND)$$PATH" \
+	  $(MAKE) -C nolibc libnolibc.a \
 	    "CC=$(MAKECONF_TOOLCHAIN)-cc" \
+	    "AR=$(MAKECONF_TOOLPREFIX)ar" \
+	    "RANLIB=$(MAKECONF_TOOLPREFIX)ranlib" \
 	    "FREESTANDING_CFLAGS=$(NOLIBC_CFLAGS)"
 
 # OPENLIBM
@@ -36,8 +39,11 @@ openlibm/libopenlibm.a: phony-openlibm
 
 .PHONY: phony-openlibm
 phony-openlibm:
-	$(MAKE) -C openlibm libopenlibm.a \
+	+env PATH="$(MAKECONF_PATH_PREPEND)$$PATH" \
+	  $(MAKE) -C openlibm libopenlibm.a \
 	     "CC=$(MAKECONF_TOOLCHAIN)-cc" \
+	     "AR=$(MAKECONF_TOOLPREFIX)ar" \
+	     "RANLIB=$(MAKECONF_TOOLPREFIX)ranlib" \
 	     "CPPFLAGS=$(LIB_CFLAGS)"
 
 # TOOLCHAIN
@@ -72,6 +78,7 @@ $(TOOLDIR_FOR_BUILD)/$(MAKECONF_TARGET_ARCH)-solo5-ocaml-%: \
 	ARCH="$(MAKECONF_TARGET_ARCH)" \
 	  SOLO5_TOOLCHAIN="$(MAKECONF_TOOLCHAIN)" \
 	  OTHERTOOLPREFIX="$(MAKECONF_TOOLPREFIX)" \
+	  PATH_PREPEND="$(MAKECONF_PATH_PREPEND)" \
 	  TOOL_CFLAGS="$(TOOLCHAIN_BUILD_CFLAGS)" \
 	  TOOL_LDFLAGS="$(TOOLCHAIN_BUILD_LDFLAGS)" \
 	  sh $< $* > $@
@@ -82,6 +89,7 @@ $(TOOLDIR_FINAL)/$(MAKECONF_TARGET_ARCH)-solo5-ocaml-%: \
 	ARCH="$(MAKECONF_TARGET_ARCH)" \
 	  SOLO5_TOOLCHAIN="$(MAKECONF_TOOLCHAIN)" \
 	  OTHERTOOLPREFIX="$(MAKECONF_TOOLPREFIX)" \
+	  PATH_PREPEND="$(MAKECONF_PATH_PREPEND)" \
 	  TOOL_CFLAGS="$(TOOLCHAIN_FINAL_CFLAGS)" \
 	  TOOL_LDFLAGS="$(TOOLCHAIN_FINAL_LDFLAGS)" \
 	  sh $< $* > $@

configure.sh

@@ -31,12 +31,17 @@ Options:
         (default: \`TARGET-cc -dumpmachine\`-).
     --ocaml-configure-option=OPTION
         Add an option to the OCaml compiler configuration.
+    --path-prepend=VAL
+        Prepend VAL to PATH in toolchain. For instance:
+        --path-prepend=/usr/local/llvm-21/bin:
+        (note the required explicit ':' separator at the end)
 EOM
     exit 1
 }
 
 OCAML_CONFIGURE_OPTIONS=
 MAKECONF_PREFIX=/usr/local
+MAKECONF_PATH_PREPEND=
 
 while [ $# -gt 0 ]; do
     OPT="$1"
@@ -57,6 +62,9 @@ while [ $# -gt 0 ]; do
         --ocaml-configure-option=*)
             OCAML_CONFIGURE_OPTIONS="${OCAML_CONFIGURE_OPTIONS} ${OPT#*=}"
             ;;
+        --path-prepend=*)
+            MAKECONF_PATH_PREPEND="${OPT#*=}"
+            ;;
         --help)
             usage
             ;;
@@ -96,4 +104,5 @@ MAKECONF_TOOLCHAIN=${CONFIG_TARGET}
 MAKECONF_TOOLPREFIX=${MAKECONF_TOOLPREFIX}
 MAKECONF_TARGET_ARCH=${TARGET_ARCH}
 MAKECONF_OCAML_CONFIGURE_OPTIONS=${OCAML_CONFIGURE_OPTIONS}
+MAKECONF_PATH_PREPEND=${MAKECONF_PATH_PREPEND}
 EOM

example/dune

@@ -26,6 +26,8 @@
 (rule
  (targets manifest.c)
  (deps manifest.json)
+ (mode promote)
+ (enabled_if %{bin-available:solo5-elftool})
  (action
   (run solo5-elftool gen-manifest manifest.json manifest.c)))
 

example/dune-project

@@ -1 +1 @@
-(lang dune 2.7)
+(lang dune 3.2)

example/manifest.c

@@ -0,0 +1,13 @@
+/* Generated by solo5-elftool version v0.12.0, do not edit */
+
+#define MFT_ENTRIES 1
+#include "mft_abi.h"
+
+MFT1_NOTE_DECLARE_BEGIN
+{
+  .version = MFT_VERSION, .entries = 1,
+  .e = {
+    { .name = "", .type = MFT_RESERVED_FIRST },
+  }
+}
+MFT1_NOTE_DECLARE_END

gen_toolchain_tool.sh

@@ -14,11 +14,12 @@ gen_cc() {
 
   CFLAGS="$TOOL_CFLAGS"
   LDFLAGS="$TOOL_LDFLAGS"
-  EXTRALIBS=""
 
+  # GCC lowers aarch64 C11 atomics to libgcc __aarch64_* outline helpers by
+  # default; inline them so the freestanding link needs no compiler runtime.
   case "$ARCH" in
     aarch64)
-      EXTRALIBS="-lgcc"
+      CFLAGS="$CFLAGS -mno-outline-atomics"
       ;;
   esac
 
@@ -35,6 +36,7 @@ gen_cc() {
 # Just like the Solo5 cc, we assume that we are linking, unless we find an
 # argument suggesting we are compiling but we call Solo5' cc regardless
 
+PATH="$PATH_PREPEND\$PATH"
 compiling=
 for arg in "\$@"; do
   case "\$arg" in
@@ -60,7 +62,6 @@ if [ -z "\$compiling" ]; then
     -Wl,--start-group \\
     -lnolibc \\
     -lopenlibm \\
-    $EXTRALIBS \\
     -Wl,--end-group
 fi
 
@@ -119,10 +120,13 @@ gen_tool() {
 
   cat << EOF
 #!/bin/sh
+PATH="$PATH_PREPEND\$PATH"
 exec $TOOL "\$@"
 EOF
 }
 
+PATH="$PATH_PREPEND$PATH"
+
 case "$1" in
   cc|gcc)
     gen_cc

nolibc/vfprintf.c

@@ -121,7 +121,10 @@ static const unsigned char states[]['z'-'A'+1] = {
 union arg
 {
 	uintmax_t i;
-	long double f;
+	/* double, not long double: avoids pulling libgcc soft-float (__extenddftf2,
+	   __trunctfdf2) into freestanding links; %L is treated as double (fmt_fp
+	   formats at double). */
+	double f;
 	void *p;
 };
 
@@ -151,7 +154,7 @@ static void pop_arg(union arg *arg, int type, va_list *ap)
 	break; case UIPTR:	arg->i = (uintptr_t)va_arg(*ap, void *);
 #endif
 	break; case DBL:	arg->f = va_arg(*ap, double);
-	break; case LDBL:	arg->f = va_arg(*ap, long double);
+	break; case LDBL:	arg->f = va_arg(*ap, double);
 	}
 }