New script to build libc and libm

(cherry picked from commit 5014f15)

Author: iartemov-ledger

tools/build_newlib.sh

@@ -0,0 +1,92 @@
+#!/usr/bin/env bash
+
+set -exu
+
+TARGET_CPU=""
+OUTPUT_DIR=""
+
+while getopts "t:o:" opt
+do
+    case "$opt" in
+        t)
+            TARGET_CPU="$OPTARG"
+            ;;
+        o)
+            OUTPUT_DIR="$OPTARG"
+            ;;
+        ?)
+            exit 1
+            ;;
+    esac
+done
+shift "$((OPTIND - 1))"
+
+if [ -z "${TARGET_CPU}" ] || [ -z "${OUTPUT_DIR}" ]
+then
+    echo "Usage: $0 -t TARGET_CPU -o OUTPUT_FILE" >&2
+    exit 1
+fi
+
+
+mkdir -p "$OUTPUT_DIR"
+OUTPUT_DIR=$(realpath "$OUTPUT_DIR")
+
+
+# ENV SETUP
+WORKDIR="$(pwd)"
+SRC="${WORKDIR}/newlib"
+BUILD="${SRC}/arm_none_eabi_build"
+INSTALL="${SRC}/arm_none_eabi_install"
+cd "${WORKDIR}"
+
+# Installing newlib build dependencies
+apt update
+apt install -y --no-install-recommends texinfo
+
+# Get the latest fixed version
+git clone --depth=1 --single-branch --branch newlib-4.5.0 https://sourceware.org/git/newlib-cygwin.git "${SRC}"
+
+# Build configuration
+mkdir -p "${BUILD}" "${INSTALL}"
+cd "${BUILD}"
+
+CFLAGS_FOR_TARGET="-ffunction-sections -fdata-sections -fshort-wchar -DPREFER_SIZE_OVER_SPEED -mcpu=${TARGET_CPU} -mthumb -mlittle-endian" \
+    ../configure  \
+    `# Setup` \
+    --host=x86_64-linux-gnu `# Host` \
+    --target=arm-none-eabi ` # Target` \
+    --disable-multilib `# Building only one library` \
+    --prefix="${INSTALL}" `#  Installation prefix` \
+    `# Options` \
+    --disable-silent-rules `# verbose build output (undo: "make V=0")` \
+    --disable-dependency-tracking `# speeds up one-time build` \
+    --enable-newlib-reent-small `# enable small reentrant struct support` \
+    --disable-newlib-fvwrite-in-streamio `# disable iov in streamio ` \
+    --disable-newlib-fseek-optimization `# disable fseek optimization` \
+    --disable-newlib-wide-orient `# Turn off wide orientation in streamio`\
+    --enable-newlib-nano-malloc `# use small-footprint nano-malloc implementation`\
+    --disable-newlib-unbuf-stream-opt `# disable unbuffered stream optimization in streamio` \
+    --enable-lite-exit `# enable light weight exit` \
+    --enable-newlib-global-atexit `# enable atexit data structure as global` \
+    --enable-newlib-nano-formatted-io `# Use small-footprint nano-formatted-IO implementation`\
+    --disable-newlib-supplied-syscalls `# disable newlib from supplying syscalls`\
+    --disable-nls `# do not use Native Language Support` \
+    --enable-target-optspace `# optimize for space (emits -g -Os)`
+
+
+# Compilation
+make "-j$(nproc)"
+make install
+
+# Removing the .ARM.exidx section
+arm-none-eabi-objcopy -R .ARM.exidx "${INSTALL}/arm-none-eabi/lib/libc.a"
+
+# Stripping debug symbols
+arm-none-eabi-strip --strip-debug "${INSTALL}/arm-none-eabi/lib/libc.a"
+arm-none-eabi-strip --strip-debug "${INSTALL}/arm-none-eabi/lib/libm.a"
+
+# Copy back
+mkdir -p "$OUTPUT_DIR"
+cp "${INSTALL}/arm-none-eabi/lib/libc.a" "$OUTPUT_DIR"
+cp "${INSTALL}/arm-none-eabi/lib/libm.a" "$OUTPUT_DIR"
+