Add CI job for producing a static bare metal binary

ci/test/00_setup_env_riscv_bare_cross.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2019-present The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+export LC_ALL=C.UTF-8
+
+export CONTAINER_NAME=ci_native_riscv_bare
+
+export CI_IMAGE_NAME_TAG="docker.io/ubuntu:24.04"
+export PACKAGES="autoconf automake autotools-dev curl python3 python3-pip libmpc-dev libmpfr-dev libgmp-dev gawk build-essential bison flex texinfo gperf libtool patchutils bc zlib1g-dev libexpat-dev ninja-build git cmake libglib2.0-dev libslirp-dev"
+export BITCOIN_CONFIG="-DCMAKE_C_COMPILER=/opt/riscv-ilp32/bin/riscv32-unknown-elf-gcc \
+ -DCMAKE_CXX_COMPILER=/opt/riscv-ilp32/bin/riscv32-unknown-elf-g++ \
+ -DBUILD_KERNEL_LIB=OFF \
+ -DBUILD_UTIL_CHAINSTATE=OFF \
+ -DBUILD_TESTS=OFF \
+ -DBUILD_BENCH=OFF \
+ -DBUILD_FUZZ_BINARY=OFF \
+ -DBUILD_DAEMON=OFF \
+ -DBUILD_TX=OFF \
+ -DBUILD_UTIL=OFF \
+ -DBUILD_CLI=OFF \
+ -DENABLE_WALLET=OFF \
+ -DCMAKE_SYSTEM_NAME=Generic \
+ "
+
+export BARE_METAL_RISCV="true"
+export RUN_UNIT_TESTS="false"
+export RUN_FUNCTIONAL_TESTS="false"
+export NO_DEPENDS="true"

ci/test/01_base_install.sh

@@ -84,6 +84,29 @@ if [[ ${USE_MEMORY_SANITIZER} == "true" ]]; then
   rm -rf /msan/llvm-project
 fi
 
+if [[ ${BARE_METAL_RISCV} == "true" ]]; then
+    ${CI_RETRY_EXE} git clone --depth=1 https://github.com/riscv-collab/riscv-gnu-toolchain -b 2024.11.22 /riscv/gcc
+    ( cd /riscv/gcc;
+      ./configure --prefix=/opt/riscv-ilp32 --with-arch=rv32gc --with-abi=ilp32;
+      make -j "$MAKEJOBS";
+      make install; )
+    rm -rf /riscv/gcc
+
+    ${CI_RETRY_EXE} git clone --depth=1 https://sourceware.org/git/newlib-cygwin.git -b topic/3.6 /riscv/newlib
+    ( cd /riscv/newlib;
+      mkdir build && cd build;
+      ../configure \
+          --target=riscv32-unknown-elf --with-arch=rv32gc --with-abi=ilp32 --disable-shared --disable-multilib\
+          --prefix=/opt/newlib \
+          CC_FOR_TARGET=/opt/riscv-ilp32/bin/riscv32-unknown-elf-gcc \
+          CXX_FOR_TARGET=/opt/riscv-ilp32/bin/riscv32-unknown-elf-g++ \
+          AR_FOR_TARGET=/opt/riscv-ilp32/bin/riscv32-unknown-elf-ar \
+          RANLIB_FOR_TARGET=/opt/riscv-ilp32/bin/riscv32-unknown-elf-ranlib
+      make -j "$MAKEJOBS";
+      make install; )
+    rm -rf /riscv/newlib
+fi
+
 if [[ "${RUN_TIDY}" == "true" ]]; then
   ${CI_RETRY_EXE} git clone --depth=1 https://github.com/include-what-you-use/include-what-you-use -b clang_"${TIDY_LLVM_V}" /include-what-you-use
   cmake -B /iwyu-build/ -G 'Unix Makefiles' -DCMAKE_PREFIX_PATH=/usr/lib/llvm-"${TIDY_LLVM_V}" -S /include-what-you-use

ci/test/03_test_script.sh

@@ -132,6 +132,61 @@ bash -c "${PRINT_CCACHE_STATISTICS}"
 du -sh "${DEPENDS_DIR}"/*/
 du -sh "${PREVIOUS_RELEASES_DIR}"
 
+if [[ ${BARE_METAL_RISCV} == "true" ]]; then
+    cmake --build . --target bitcoin_consensus
+
+    echo -e "#include <script/script_error.h>\n int main() { return ScriptErrorString(ScriptError_t::SCRIPT_ERR_UNKNOWN_ERROR).size() > 0; }" > test.cpp
+
+    /opt/riscv-ilp32/bin/riscv32-unknown-elf-g++ -I "${BASE_ROOT_DIR}"/src -g -std=c++20 -march=rv32gc -mabi=ilp32 -c test.cpp -o test.o
+
+    echo -e ".section .text
+          .global _start
+          .type _start, @function
+
+          _start:
+              .option push
+              .option norelax
+              la gp, __global_pointer$
+              .option pop
+
+              call main
+
+              # Put Exit2 system call number into the a7 register
+              li a7, 93
+              ecall" > start.s
+
+    /opt/riscv-ilp32/bin/riscv32-unknown-elf-gcc -c start.s -o start.o
+
+    echo -e "#include <sys/stat.h>
+          void _exit(int code) { while(1); }
+          int _sbrk(int incr) { return 0; }
+          int _write(int file, char *ptr, int len) { return 0; }
+          int _close(int file) { return -1; }
+          int _fstat(int file, struct stat *st) { st->st_mode = S_IFCHR; return 0; }
+          int _isatty(int file) { return 1; }
+          int _lseek(int file, int ptr, int dir) { return 0; }
+          int _read(int file, char *ptr, int len) { return 0; }
+          int _kill(int pid, int sig) { return -1; }
+          int _getpid(void) { return -1; }" > syscalls.c
+
+    /opt/riscv-ilp32/bin/riscv32-unknown-elf-gcc -g -march=rv32i -mabi=ilp32 -c syscalls.c -o syscalls.o
+
+    /opt/riscv-ilp32/bin/riscv32-unknown-elf-g++ -g -std=c++20 -march=rv32gc -mabi=ilp32 \
+        -nostdlib \
+        /opt/riscv-ilp32/lib/gcc/riscv32-unknown-elf/14.2.0/crtbegin.o \
+        test.o \
+        start.o \
+        syscalls.o \
+        src/libbitcoin_consensus.a \
+        src/crypto/libbitcoin_crypto.a \
+        src/secp256k1/lib/libsecp256k1.a \
+        /opt/riscv-ilp32/riscv32-unknown-elf/lib/libstdc++.a \
+        /opt/newlib/riscv32-unknown-elf/lib/libc.a \
+        /opt/newlib/riscv32-unknown-elf/lib/libm.a \
+        /opt/riscv-ilp32/lib/gcc/riscv32-unknown-elf/14.2.0/libgcc.a \
+        -o test.elf
+fi
+
 if [[ $HOST = *-mingw32 ]]; then
   "${BASE_ROOT_DIR}/ci/test/wrap-wine.sh"
 fi