chore: determine the current architecture in build time (#49)

More podman and non-buildx friendly

Author: adelton

builder/Dockerfile

@@ -1,6 +1,6 @@
 ARG OS_CODENAME=jammy
 
-FROM ubuntu:${OS_CODENAME} AS base
+FROM ubuntu:${OS_CODENAME}
 
 ARG DEBIAN_FRONTEND=noninteractive
 ARG GCC_ARM_VERSION=14.2.rel1
@@ -38,21 +38,12 @@ RUN uv venv \
 # Add venv to PATH
 ENV PATH="$VIRTUAL_ENV/bin:$PATH"
 
-FROM base AS base-amd64
-ENV GCC_ARM_ARCH=x86_64
-
-FROM base AS base-arm64
-ENV GCC_ARM_ARCH=aarch64
-
-ARG TARGETARCH
-
-FROM base-${TARGETARCH}
-
 # Install ARM toolchain
-RUN wget --quiet https://developer.arm.com/-/media/Files/downloads/gnu/${GCC_ARM_VERSION}/binrel/arm-gnu-toolchain-${GCC_ARM_VERSION}-${GCC_ARM_ARCH}-arm-none-eabi.tar.xz -O - \
-        | tar -xJ -C /opt
+RUN wget --quiet https://developer.arm.com/-/media/Files/downloads/gnu/${GCC_ARM_VERSION}/binrel/arm-gnu-toolchain-${GCC_ARM_VERSION}-$( uname -m )-arm-none-eabi.tar.xz -O - \
+        | tar -xJ -C /opt \
+	&& ln -s /opt/arm-gnu-toolchain-*-arm-none-eabi /opt/arm-gnu-toolchain-arm-none-eabi
 
-ENV PATH=/opt/arm-gnu-toolchain-${GCC_ARM_VERSION}-${GCC_ARM_ARCH}-arm-none-eabi/bin/:${PATH}
+ENV PATH=/opt/arm-gnu-toolchain-arm-none-eabi/bin/:${PATH}
 
 VOLUME ["/src"]
 ENTRYPOINT ["/usr/bin/dumb-init", "--"]