add compatibility tests using good example code off the net

The test script will fetch the ESP-IDF framework to have all necessary
include files, and will then fetch two sources of example code (ulptool and
binutil-esp32_ulp's own test examples).

The examples are fetched rather than duplicated into this repo, to avoid
potential licensing and attribution issues.

Author: wnienhaus

Diff for: .github/workflows/run_tests.yaml

@@ -70,5 +70,13 @@ jobs:
         export PATH=$PATH:${{ steps.build_micropython.outputs.bin_dir }}
         export PATH=$PATH:${{ steps.build_binutils.outputs.bin_dir }}
         cd tests
-        ln -s ../binutils-esp32ulp  # already cloned earlier. reuse.
         ./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 }}
+        cd tests
+        ln -s ../binutils-esp32ulp  # already cloned earlier. reuse.
+        ./02_compat_rtc_tests.sh

Diff for: tests/02_compat_rtc_tests.sh

@@ -0,0 +1,118 @@
+#!/bin/bash
+
+# export PYTHONPATH=.:$PYTHONPATH
+
+set -e
+
+make_log_dir() {
+   mkdir -p log
+}
+
+fetch_esp_idf() {
+    [ -d esp-idf ] && return
+
+    echo "Fetching esp-idf"
+    log_file=log/fetch-esp-idf.log
+    git clone --depth 1 \
+        https://github.com/espressif/esp-idf.git 1>$log_file 2>&1
+}
+
+fetch_ulptool_examples() {
+    [ -d ulptool ] && return
+
+    echo "Fetching ulptool examples"
+    log_file=log/fetch-ulptool.log
+    git clone --depth 1 \
+        https://github.com/duff2013/ulptool 1>$log_file 2>&1
+}
+
+fetch_binutils_esp32ulp_examples() {
+    [ -d binutils-esp32ulp ] && return
+
+    echo "Fetching binutils-esp32ulp examples"
+    log_file=log/fetch-binutils.log
+    git clone --depth 1 \
+        https://github.com/espressif/binutils-esp32ulp.git 1>$log_file 2>&1
+}
+
+build_defines_db() {
+    local defines_db=defines.db
+
+    if [ "$1" = "-r" ] && [ -s "${defines_db}" ]; then
+        # reuse existing defines.db
+        return
+    fi
+
+    echo "Building defines DB from include files"
+    log_file=log/build_defines_db.log
+    rm -f "${defines_db}"
+    micropython -m esp32_ulp.parse_to_db \
+        esp-idf/components/soc/esp32/include/soc/*.h \
+        esp-idf/components/esp_common/include/*.h 1>$log_file
+}
+
+make_log_dir
+fetch_esp_idf
+fetch_ulptool_examples
+fetch_binutils_esp32ulp_examples
+build_defines_db $1
+
+for src_file in ulptool/src/ulp_examples/*/*.s binutils-esp32ulp/gas/testsuite/gas/esp32ulp/esp32/*.s; do
+
+    src_name="${src_file%.s}"
+
+    echo "Testing $src_file"
+
+    test_name="${src_name##*/}"
+
+    # for now, skip files that contain known bugs in esp32_ulp (essentially a todo list of what to fix)
+    for I in rtcio esp32ulp_all esp32ulp_globals esp32ulp_jumpr esp32ulp_ranges test_reg; do
+        if [ "${test_name}" = "$I" ]; then
+            # these are old bugs, and not related to the RTC macro handling functionality
+            # they will still be great to fix over time
+            echo -e "\tSkipping... known bugs in esp32_ulp"
+            continue 2
+        fi
+    done
+
+    # for now, skip files that contain unsupported things (macros)
+    for I in i2c i2c_dev stack i2c_wr test1 test_jumpr test_macro; do
+        if [ "${test_name}" = "$I" ]; then
+            echo -e "\tSkipping... not yet supported"
+            continue 2
+        fi
+    done
+
+    echo -e "\tBuilding using py-esp32-ulp"
+    ulp_file="${src_name}.ulp"
+    log_file="${src_name}.log"
+    micropython -m esp32_ulp $src_file 1>$log_file   # generates $ulp_file
+
+    pre_file="${src_name}.pre"
+    obj_file="${src_name}.o"
+    elf_file="${src_name}.elf"
+    bin_file="${src_name}.bin"
+
+    echo -e "\tBuilding using binutils"
+    gcc -I esp-idf/components/soc/esp32/include -I esp-idf/components/esp_common/include \
+        -x assembler-with-cpp \
+        -E -o ${pre_file} $src_file
+    esp32ulp-elf-as -o $obj_file ${pre_file}
+    esp32ulp-elf-ld -T esp32.ulp.ld -o $elf_file $obj_file
+    esp32ulp-elf-objcopy -O binary $elf_file $bin_file
+
+    if ! diff $ulp_file $bin_file 1>/dev/null; then
+        echo -e "\tBuild outputs differ!"
+        echo ""
+        echo "Compatibility test failed for $src_file"
+        echo "py-esp32-ulp log:"
+        cat $log_file
+        echo "py-esp32-ulp output:"
+        xxd $ulp_file
+        echo "binutils output:"
+        xxd $bin_file
+        exit 1
+    else
+        echo -e "\tBuild outputs match"
+    fi
+done