tools: use riscv32-esp-elf toolchain for ESP32-S2 RISC-V ULP

riscv32-esp-elf toolchain (used for ESP32-C3) can also be used for
ESP32-S2 RISC-V ULP coprocessor.

This removes the riscv-none-embed-gcc toolchain which was originally
used for the ULP, and updates the docs and CMake files to use
riscv32-esp-elf.

Some flags are cleaned up and workarounds removed from CMake toolchain
file.

components/ulp/cmake/toolchain-esp32s2-ulp-riscv.cmake

@@ -1,18 +1,15 @@
 # CMake toolchain file for ULP-RISC-V
 set(CMAKE_SYSTEM_NAME Generic)
 
-# Not best solution, needs to figure why the compiler detection
-# fails in CI
-set(CMAKE_C_COMPILER_FORCED TRUE)
-set(CMAKE_CXX_COMPILER_FORCED TRUE)
-
-set(CMAKE_C_COMPILER "riscv-none-embed-gcc")
-set(CMAKE_ASM_COMPILER "riscv-none-embed-gcc")
-
-if(NOT ASM_DIALECT)
-    set(ASM_DIALECT "")
-endif()
-
-set(CMAKE_C_FLAGS "-Os -march=rv32imc -mdiv -fdata-sections -ffunction-sections")
-set(CMAKE_ASM_FLAGS "-march=rv32imc -mdiv -x assembler-with-cpp -fdata-sections -ffunction-sections")
-set(CMAKE_EXE_LINKER_FLAGS "-march=rv32imc --specs=nano.specs --specs=nosys.specs")
+set(CMAKE_C_COMPILER "riscv32-esp-elf-gcc")
+set(CMAKE_CXX_COMPILER "riscv32-esp-elf-g++")
+set(CMAKE_ASM_COMPILER "riscv32-esp-elf-gcc")
+
+set(CMAKE_C_FLAGS "-Os -march=rv32imc -mdiv -fdata-sections -ffunction-sections"
+    CACHE STRING "C Compiler Base Flags")
+set(CMAKE_CXX_FLAGS "-Os -march=rv32imc -mdiv -fdata-sections -ffunction-sections"
+    CACHE STRING "C++ Compiler Base Flags")
+set(CMAKE_ASM_FLAGS "-march=rv32imc -x assembler-with-cpp"
+    CACHE STRING "Assembler Base Flags")
+set(CMAKE_EXE_LINKER_FLAGS "-march=rv32imc --specs=nano.specs --specs=nosys.specs"
+    CACHE STRING "Linker Base Flags")

docs/en/api-guides/tools/idf-tools-notes.inc

@@ -25,11 +25,6 @@
 .. tool-esp32s2ulp-elf-notes
 
 
----
-
-.. tool-riscv-none-embed-gcc-notes
-
-
 ---
 
 .. tool-openocd-esp32-notes

docs/en/api-guides/ulp-risc-v.rst

@@ -11,11 +11,11 @@ The ULP-RISC-V coprocessor is a variant of the ULP, present in ESP32-S2. Similar
 Installing the ULP-RISC-V Toolchain
 -----------------------------------
 
-The ULP-RISC-V coprocessor code is written in C (assembly is also possible) and compiled using the `riscv-embedded toolchain`_.
+The ULP-RISC-V coprocessor code is written in C (assembly is also possible) and compiled using RISC-V toolchain based on GCC.
 
-If you have already set up ESP-IDF with CMake build system according to the :doc:`Getting Started Guide <../../get-started/index>`, then you need to perform an extra step to get the ULP-RISC-V toolchain installed, execute the command below inside the IDF folder::
+If you have already set up ESP-IDF with CMake build system according to the :doc:`Getting Started Guide <../../get-started/index>`, then the toolchain should already be installed.
 
-$ idf_tools.py install riscv-none-embed-gcc
+.. note: In earlier versions of ESP-IDF, RISC-V toolchain had a different prefix: `riscv-none-embed-gcc`.
 
 
 Compiling the ULP-RISC-V Code
@@ -56,7 +56,7 @@ To compile the ULP-RISC-V code as part of the component, the following steps mus
 
    5. **Dump the contents of the ELF file into a binary** (``ulp_app_name.bin``) which can then be embedded into the application.
 
-   6. **Generate a list of global symbols** (``ulp_app_name.sym``) in the ELF file using ``riscv-none-embed-nm``.
+   6. **Generate a list of global symbols** (``ulp_app_name.sym``) in the ELF file using ``riscv32-esp-elf-nm``.
 
    7. **Create an LD export script and header file** (``ulp_app_name.ld`` and ``ulp_app_name.h``) containing the symbols from ``ulp_app_name.sym``. This is done using the ``esp32ulp_mapgen.py`` utility.
 
@@ -147,5 +147,3 @@ The program runs until the field ``RTC_CNTL_COCPU_DONE`` in register ``RTC_CNTL_
 
 To disable the timer (effectively preventing the ULP program from running again), please clear the ``RTC_CNTL_ULP_CP_SLP_TIMER_EN`` bit in the ``RTC_CNTL_STATE0_REG`` register. This can be done both from the ULP code and from the main program.
 
-
-.. _riscv-embedded toolchain: https://xpack.github.io/riscv-none-embed-gcc/

docs/zh_CN/api-guides/tools/idf-tools-notes.inc

@@ -27,11 +27,6 @@
 .. tool-esp32s2ulp-elf-notes
 
 
----
-
-.. tool-riscv-none-embed-gcc-notes
-
-
 ---
 
 .. tool-openocd-esp32-notes

docs/zh_CN/api-guides/ulp-risc-v.rst

@@ -11,12 +11,11 @@ ULP-RISC-V 协处理器是 ULP 的一种变体，用于 ESP32-S2。与 ULP 类
 安装 ULP-RISC-V 工具链
 -----------------------------------
 
-ULP-RISC-V 协处理器代码以 C 语言编写（也可能是汇编语言），使用 `riscv-embedded toolchain`_ 进行编译。
+ULP-RISC-V 协处理器代码以 C 语言编写（也可能是汇编语言），使用基于GCC的 RISC-V 工具链进行编译。
 
-如果你已依照 :doc:`快速入门指南 <../../get-started/index>` 中的介绍安装好了 ESP-IDF 及其 CMake 构建系统，还需要在 IDF 文件夹中执行以下指令，安装 ULP-RISC-V 工具链::
-
-$ idf_tools.py install riscv-none-embed-gcc
+如果你已依照 :doc:`快速入门指南 <../../get-started/index>` 中的介绍安装好了 ESP-IDF 及其 CMake 构建系统，那么 ULP-RISC-V 工具链已经被默认安装到了你的开发环境中。
 
+.. note: 在早期版本的ESP-IDF中，RISC-V工具链具有不同的名称：`riscv-none-embed-gcc`。
 
 编译 ULP-RISC-V 代码
 -----------------------------
@@ -25,7 +24,7 @@ $ idf_tools.py install riscv-none-embed-gcc
 
 1. ULP-RISC-V 代码以 C 语言或汇编语言编写（必须使用 `.S` 扩展名)，必须放在组件目录中一个独立的目录中，例如 `ulp/`。
 
-.. 注意：当注册组件时（通过 ``idf_component_register``），该目录不应被添加至 ``SRC_DIRS`` 参数，因为目前 ULP-FSM 需要进行此步骤。如何正确添加 ULP 源文件，请见以下步骤。
+.. note: 当注册组件时（通过 ``idf_component_register``），该目录不应被添加至 ``SRC_DIRS`` 参数，因为目前 ULP-FSM 需要进行此步骤。如何正确添加 ULP 源文件，请见以下步骤。
 
 2. 注册后从组件 CMakeLists.txt 中调用 ``ulp_embed_binary`` 示例如下::
 
@@ -147,5 +146,3 @@ ULP-RISC-V 协处理器由定时器启动，调用 :cpp:func:`ulp_riscv_run` 即
 
 如需禁用定时器（有效防止 ULP 程序再次运行），请清除 ``RTC_CNTL_STATE0_REG`` 寄存器中的 ``RTC_CNTL_ULP_CP_SLP_TIMER_EN`` 位，此项操作可在 ULP 代码或主程序中进行。
 
-
-.. _riscv-embedded toolchain: https://xpack.github.io/riscv-none-embed-gcc/

tools/ci/config/build.yml

@@ -115,9 +115,6 @@ build_ssc_esp32s2:
     TEST_TYPE: "unit_test"
     PYTHON_VER: 3
   script:
-    # RISC-V toolchain is optional but ULP may need it, so install:
-    - $IDF_PATH/tools/idf_tools.py install riscv-none-embed-gcc
-    - . $IDF_PATH/export.sh
     - ${IDF_PATH}/tools/ci/find_apps_build_apps.sh
     - cd $CI_PROJECT_DIR/tools/unit-test-app
     - python tools/UnitTestParser.py ${BUILD_PATH}
@@ -155,9 +152,6 @@ build_esp_idf_tests_cmake_esp32s3:
     BUILD_PATH: ${CI_PROJECT_DIR}/build_${TEST_PREFIX}
     PYTHON_VER: 3
   script:
-    # RISC-V toolchain is optional but ULP may need it, so install:
-    - $IDF_PATH/tools/idf_tools.py install riscv-none-embed-gcc
-    - . $IDF_PATH/export.sh
     # it's not possible to build 100% out-of-tree and have the "artifacts"
     # mechanism work, but this is the next best thing
     - ${IDF_PATH}/tools/ci/find_apps_build_apps.sh

tools/tools.json

@@ -51,7 +51,7 @@
           "win64": {
             "sha256": "58419852fefb7111fdec056ac2fd7c4bd09c1f4c17610a761a97b788413527cf",
             "size": 106855139,
-            "url": "https://github.com/espressif/crosstool-NG/releases/download/esp-2020r3/xtensa-esp32-elf-gcc8_4_0-esp-2020r3-win64.zip"
+            "url": "https://dl.espressif.com/dl/xtensa-esp32-elf-gcc8_4_0-esp-2020r3-win64.zip"
           }
         }
       ]
@@ -169,58 +169,56 @@
       ]
     },
     {
-      "description": "Toolchain for RISC-V",
+      "description": "Toolchain for 32-bit RISC-V based on GCC",
       "export_paths": [
         [
-          "xPacks",
-          "riscv-none-embed-gcc",
-          "8.2.0-3.1",
+          "riscv32-esp-elf",
           "bin"
         ]
       ],
       "export_vars": {},
-      "info_url": "https://github.com/xpack-dev-tools/riscv-none-embed-gcc-xpack",
-      "install": "on_request",
-      "license": "MIT",
-      "name": "riscv-none-embed-gcc",
+      "info_url": "https://github.com/espressif/crosstool-NG",
+      "install": "always",
+      "license": "GPL-3.0-with-GCC-exception",
+      "name": "riscv32-esp-elf",
       "version_cmd": [
-        "riscv-none-embed-gcc",
+        "riscv32-esp-elf-gcc",
         "--version"
       ],
-      "version_regex": "(riscv-none-embed-gcc) \\(xPack GNU RISC-V Embedded GCC, 64-bit\\) (8.2.0)",
+      "version_regex": "\\(crosstool-NG\\s+(?:crosstool-ng-)?([0-9a-zA-Z\\.\\-_]+)\\)\\s*([0-9\\.]+)",
       "version_regex_replace": "\\1-\\2",
       "versions": [
         {
           "linux-amd64": {
-            "sha256": "3d40fab50ebad8424ff85748f25d2eaee50f86a5d5222abd7a45a2e490f1e4f5",
-            "size": 216042047,
-            "url": "https://github.com/xpack-dev-tools/riscv-none-embed-gcc-xpack/releases/download/v8.2.0-3.1/xpack-riscv-none-embed-gcc-8.2.0-3.1-linux-x64.tgz"
+            "sha256": "425454c5c4e2cde5dd2dd3a1d398befc70addf71547840fb6d0ec4b307b08894",
+            "size": 152042971,
+            "url": "https://dl.espressif.com/dl/toolchains/preview/riscv32-esp-elf-gcc8_4_0-crosstool-ng-1.24.0-123-g64eb9ff-linux-amd64.tar.gz"
           },
-          "linux-i686": {
-            "sha256": "2e856ee33ef544a2405183366cdf299da2cca697e8cc57627dfaad8ab4460a99",
-            "size": 219854326,
-            "url": "https://github.com/xpack-dev-tools/riscv-none-embed-gcc-xpack/releases/download/v8.2.0-3.1/xpack-riscv-none-embed-gcc-8.2.0-3.1-linux-x32.tgz"
+          "linux-armel": {
+            "sha256": "8ae098751b5196ca8a80d832cc9930bc4d639762a6cb22be3cfe0a8d71b2f230",
+            "size": 150801079,
+            "url": "https://dl.espressif.com/dl/toolchains/preview/riscv32-esp-elf-gcc8_4_0-crosstool-ng-1.24.0-123-g64eb9ff-linux-armel.tar.gz"
           },
           "macos": {
-            "sha256": "48ece50b7272a8e49e56e37f54f9962f93dce4ca44f1bb4c8113fab0230fbdf1",
-            "size": 214715632,
-            "url": "https://github.com/xpack-dev-tools/riscv-none-embed-gcc-xpack/releases/download/v8.2.0-3.1/xpack-riscv-none-embed-gcc-8.2.0-3.1-darwin-x64.tgz"
+            "sha256": "35b1aef85b7e6b4268774f627e8e835d087bcf8b9972cfb6436614aa2e40d4a9",
+            "size": 158594401,
+            "url": "https://dl.espressif.com/dl/toolchains/preview/riscv32-esp-elf-gcc8_4_0-crosstool-ng-1.24.0-123-g64eb9ff-macos.tar.gz"
           },
-          "name": "riscv-none-embed-gcc-8.2.0",
+          "name": "1.24.0.123_64eb9ff-8.4.0",
           "status": "recommended",
           "win32": {
-            "sha256": "78bcd52f7b404133de3b2f9568e7101c1de747f98db3a7b0d6251b75a1754867",
-            "size": 232387519,
-            "url": "https://github.com/xpack-dev-tools/riscv-none-embed-gcc-xpack/releases/download/v8.2.0-3.1/xpack-riscv-none-embed-gcc-8.2.0-3.1-win32-x32.zip"
+            "sha256": "4f576b08620f57c270ac677cc94dce2767fff72d27a539e348d448f63b480d1f",
+            "size": 190014086,
+            "url": "https://dl.espressif.com/dl/toolchains/preview/riscv32-esp-elf-gcc8_4_0-crosstool-ng-1.24.0-123-g64eb9ff-win32.zip"
           },
           "win64": {
-            "sha256": "98b60720607f1400081806d60d70796b30399f8b426e2c790a4abb0bffb9e5ec",
-            "size": 241927614,
-            "url": "https://github.com/xpack-dev-tools/riscv-none-embed-gcc-xpack/releases/download/v8.2.0-3.1/xpack-riscv-none-embed-gcc-8.2.0-3.1-win32-x64.zip"
+            "sha256": "51e392ed88498f3fc4ad07e9ff4b5225f6533b1c363ecd7dd67c10d8d31b6b23",
+            "size": 191565525,
+            "url": "https://dl.espressif.com/dl/toolchains/preview/riscv32-esp-elf-gcc8_4_0-crosstool-ng-1.24.0-123-g64eb9ff-win64.zip"
           }
         }
       ]
-    },
+    }
     {
       "description": "Toolchain for ESP32 ULP coprocessor",
       "export_paths": [