Switch to new esp32ulp tool (binutils-gdb vs binutils-esp32ulp)

Espressif has switched from the binutils-esp32ulp repo (the original
fork of binutils to support their microcontrollers) to their new
repo binutils-gdb. (see espressif/esp-idf@a9bd454)

The ESP-IDF also uses the esp32ulp assembler/linker from the new
repo now. The main difference is that this is now the officially
maintained implementation. The other difference is that there are now
not different binaries for each esp32 variant, but one set of binaries.

To select which esp32 variant to target, the esp32ulp-elf-as binary
now accepts the --mcpu argument, for example --mcpu=esp32s2. The
default is still the original esp32, so omitting the argument means
one effected selected --mcpu=esp32.

Note: Because Espressif provides pre-built binaries we are no longer
building esp32ulp, but simply downloading the binaries and using
those.

Author: wnienhaus

.github/workflows/run_tests.yaml

@@ -40,25 +40,32 @@ jobs:
         test $(micropython -c 'print("test")') = "test"
         popd
 
-    - name: Build binutils-esp32ulp
-      id: build_binutils
+    - name: Fetch binutils-esp32ulp
+      id: fetch_binutils
       run: |
-        echo "Building binutils-esp32ulp"
-        # building requires an older version of gcc
-        sudo apt-get install -y gcc-7 g++-7
-        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 7
-        sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 7
-        git clone --depth 1 https://github.com/espressif/binutils-esp32ulp.git
-        pushd binutils-esp32ulp
-        git describe --always --tags
-        ./configure --target=esp32ulp-elf --prefix=$PWD/dist --disable-doc --disable-gdb --disable-libdecnumber --disable-readline --disable-sim
-        echo "MAKEINFO = :" >> Makefile
-        make
-        make install-strip
-        export PATH=$PATH:$PWD/dist/bin
-        echo "bin_dir=$PWD/dist/bin" >> $GITHUB_OUTPUT
+        echo "Fetching URL of pre-built esp32ulp-elf binaries"
+        ## URL to pre-built binaries is published in esp-idf
+        IDFVER=v5.0.1
+        curl -s \
+          -o tools.json \
+          https://raw.githubusercontent.com/espressif/esp-idf/$IDFVER/tools/tools.json
+        URL=$(<tools.json jq -r '
+          .tools[]
+            | select(.name == "esp32ulp-elf").versions[]
+            | select(.status == "recommended")
+            | .["linux-amd64"]
+            | .url
+            // empty
+        ')
+
+        echo "Downloading esp32ulp-elf from $URL"
+        curl -sL \
+           -o /tmp/esp32ulp-elf.tar.gz \
+           $URL
+        tar xfvz /tmp/esp32ulp-elf.tar.gz esp32ulp-elf/bin
+        export PATH=$PATH:$PWD/esp32ulp-elf/bin
+        echo "bin_dir=$PWD/esp32ulp-elf/bin" >> $GITHUB_OUTPUT
         esp32ulp-elf-as --version | grep 'esp32ulp-elf' > /dev/null
-        popd
 
     ###### Run tests ######
 
@@ -73,15 +80,14 @@ jobs:
       id: compat_tests
       run: |
         export PATH=$PATH:${{ steps.build_micropython.outputs.bin_dir }}
-        export PATH=$PATH:${{ steps.build_binutils.outputs.bin_dir }}
+        export PATH=$PATH:${{ steps.fetch_binutils.outputs.bin_dir }}
         cd tests
         ./01_compat_tests.sh
 
     - name: Run compat tests with RTC macros
       id: compat_rtc_tests
       run: |
         export PATH=$PATH:${{ steps.build_micropython.outputs.bin_dir }}
-        export PATH=$PATH:${{ steps.build_binutils.outputs.bin_dir }}
+        export PATH=$PATH:${{ steps.fetch_binutils.outputs.bin_dir }}
         cd tests
-        ln -s ../binutils-esp32ulp  # already cloned earlier. reuse.
         ./02_compat_rtc_tests.sh