From 08b42146b0927e769ede9ae4c80efe40cb539cc3 Mon Sep 17 00:00:00 2001
From: Gary Tierney <gary.tierney@fastmail.com>
Date: Sun, 9 Mar 2025 10:35:14 +0000
Subject: [PATCH] Disable dynamic CRT linkage

---
 .github/workflows/push.yml |  4 +++
 Dockerfile                 |  3 +-
 README.md                  | 62 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 README.md

diff --git a/.github/workflows/push.yml b/.github/workflows/push.yml
index fb46497..cb8d285 100644
--- a/.github/workflows/push.yml
+++ b/.github/workflows/push.yml
@@ -22,8 +22,10 @@ jobs:
         platform:
           - docker: linux/amd64
             runner: ubuntu-24.04
+            rust: x86_64-unknown-linux-gnu
           - docker: linux/arm64
             runner: ubuntu-24.04-arm
+            rust: aarch64-unknown-linux-gnu
     steps:
       - name: Prepare
         run: |
@@ -62,6 +64,8 @@ jobs:
           outputs: type=image,push-by-digest=true,name-canonical=true,push=true
           cache-from: type=registry,ref=${{ env.REGISTRY_IMAGE }}:cache
           cache-to: type=inline
+          build-args:
+            TARGET=${{ matrix.platform.rust }}
 
       - name: Export digest
         run: |
diff --git a/Dockerfile b/Dockerfile
index 0d732d9..c983ecd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,13 +8,14 @@ ENV RUSTUP_HOME=/usr/local/rustup \
     PATH=/usr/local/cargo/bin:$PATH \
     RUST_VERSION=1.85.0
 
+ARG TARGET
 WORKDIR /work
 RUN --mount=type=cache,target=/usr/local/cargo/registry \
     --mount=type=cache,target=/usr/local/rustup \
     --mount=type=bind,target=/work,rw \
     curl https://sh.rustup.rs -sSf | bash -s -- -y --default-toolchain "${RUST_VERSION}" && \
     rustup install stable && \
-    cargo build --locked --release && \
+    RUSTFLAGS='-C target-feature=+crt-static' cargo build --locked --release --target ${TARGET} && \
     mkdir /out/ && mv /work/target/${TARGET}/release/my-cpu /out/
 
 FROM scratch
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..91ab2f0
--- /dev/null
+++ b/README.md
@@ -0,0 +1,62 @@
+# my-cpu
+
+A utility to detect the current CPU and select a matching binary to run from the result.
+
+## Overview
+
+`my-cpu` is a tool that helps you run CPU-specific binaries by detecting the host CPU architecture and matching it against provided patterns. This is useful for running optimized binaries based on the CPU capabilities of the host system.
+
+## Features
+
+- Automatic CPU detection using LLVM
+- Regular expression based matching for CPU selection
+- Fallback binary support
+- Command passthrough to selected binary
+
+## Installation
+
+### From Source
+
+```bash
+cargo build --release
+```
+
+### Using Docker
+
+```bash
+docker build -t my-cpu .
+```
+
+## Usage
+
+```bash
+my-cpu --fallback /path/to/fallback/binary -t /path/to/binary:regex [command args...]
+```
+
+### Arguments
+
+- `--fallback <PATH>`: Path to the fallback binary to be used if the CPU cannot be detected or there are no matches
+- `-t, --target <PATH:REGEX>`: One or more target pairs specified as path to binary and a regex pattern to match against the CPU name
+- `[command...]`: The command arguments to pass to the selected binary
+
+### Example
+
+```bash
+my-cpu --fallback /usr/bin/app-generic \
+       -t /usr/bin/app-x64-v4:x86-64-v4 \
+       -t /usr/bin/app-avx512:".*avx512.*" \
+       -- --some-arg value
+```
+
+This will:
+1. Detect the current CPU
+2. Try to match it against the provided patterns
+3. Run the matching binary (or fallback) with the provided arguments
+
+## Building
+
+### Requirements
+
+- Rust 1.85.0 or later
+- LLVM 19 or later
+- C++ compiler