scripts: Split installing Rust to its own script

Signed-off-by: Tim Crawford <tcrawford@system76.com>

scripts/install-deps.sh

@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-3.0-only
 
 set -eE
 
@@ -101,22 +102,8 @@ curl -sSf https://review.coreboot.org/tools/hooks/commit-msg \
   -o .git/modules/coreboot/hooks/commit-msg && \
   chmod +x .git/modules/coreboot/hooks/commit-msg
 
-RUSTUP_NEW_INSTALL=0
-if which rustup &> /dev/null; then
-  msg "Updating rustup"
-  rustup self update
-else
-  RUSTUP_NEW_INSTALL=1
-  msg "Installing Rust"
-  curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
-    | sh -s -- -y --default-toolchain stable
-
-  msg "Loading Rust environment"
-  source "${HOME}/.cargo/env"
-fi
-
-msg "Installing pinned Rust toolchain and components"
-rustup show
+msg "Installing Rust toolchain and components"
+./scripts/install-rust.sh
 
 msg "Installing EC dependencies"
 pushd ec
@@ -129,10 +116,5 @@ make CPUS="$(nproc)" crossgcc-i386
 make CPUS="$(nproc)" crossgcc-x64
 popd
 
-if [[ $RUSTUP_NEW_INSTALL = 1 ]]; then
-    msg "\x1B[33m>> rustup was just installed. Ensure cargo is on the PATH with:"
-    echo -e "    source ~/.cargo/env\n"
-fi
-
 msg "\x1B[32mSuccessfully installed dependencies"
 echo "Ready to run ./scripts/build.sh [model]" >&2

scripts/install-rust.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-3.0-only
+
+# Install Rust via rustup, along with the pinned toolchain.
+
+# shellcheck shell=dash
+# shellcheck disable=SC1091
+
+set -Ee
+
+RUSTUP_NEW_INSTALL=0
+
+# NOTE: rustup is used to allow multiple toolchain installations.
+if command -v rustup >/dev/null 2>&1; then
+    rustup self update
+else
+    RUSTUP_NEW_INSTALL=1
+    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
+        | sh -s -- -y --default-toolchain stable
+
+    . "${HOME}/.cargo/env"
+fi
+
+# XXX: rustup has no command to install a toolchain from a TOML file.
+# Rely on the fact that `show` will install the default toolchain.
+rustup show
+
+if [ "$RUSTUP_NEW_INSTALL" = "1" ]; then
+    printf "\e[33m>> rustup was just installed. Ensure cargo is on the PATH with:\e[0m\n"
+    printf "    source ~/.cargo/env\n\n"
+fi