Add support to ESP32C3

.envrc

@@ -3,4 +3,7 @@ if ! has nix_direnv_version || ! nix_direnv_version 3.0.3; then
   source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/3.0.3/direnvrc" "sha256-0EVQVNSRQWsln+rgPW3mXVmnF5sfcmKEYOmOSfLYxHg="
 fi
 
+watch_file mbed-os.nix
+watch_file libopencm3.nix
+watch_file esp-idf-lib.nix
 use flake

.github/workflows/build.yaml

@@ -21,6 +21,7 @@ jobs:
         script: |
           astyle --version
           arm-none-eabi-gcc --version
+          riscv32-esp-elf-gcc --version
           qemu-system-arm --version
     - name: Lint
       run: |
@@ -43,6 +44,7 @@ jobs:
 
           export -f make_platform
           tests --list-platforms | grep -v "mps2" | xargs -I {} bash -c 'make_platform "$@" || exit 1' _ {}
+          make_platform "esp32-c3"
 
     - name: Functional test
       id: func_test

esp-idf-lib.nix

@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: Apache-2.0
+
+{ stdenvNoCC
+, writeText
+, esp-idf-esp32c3
+, git
+, python3Packages
+, fetchPypi
+}:
+let
+  version = "v5.3";
+
+  # new dependency for v5.2.x
+  pyclang = python3Packages.buildPythonPackage rec {
+    pname = "pyclang";
+    version = "0.4.2";
+
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "sha256-vuDZ5yEhyDpCmkXoC+Gr2X5vMK5B46HnktcvBONjxXM=";
+    };
+
+    doCheck = false;
+  };
+
+  # new dependency for v5.3
+  esp-idf-nvs-partition-gen = python3Packages.buildPythonPackage rec {
+    pname = "esp_idf_nvs_partition_gen";
+    version = "0.1.2";
+    format = "pyproject";
+
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "sha256-HjW5RCKfy83LQgAs0tOW/f9LPVoLwHY1pyb6ar+AxwY=";
+    };
+
+    propagatedBuildInputs = builtins.attrValues {
+      inherit (python3Packages)
+        setuptools
+        cryptography;
+    };
+
+    doCheck = false;
+  };
+
+  esp-idf-esp32c3' = (esp-idf-esp32c3.overrideAttrs (old: {
+    propagatedBuildInputs = builtins.filter (p: p != git) old.propagatedBuildInputs ++
+      [
+        pyclang
+        esp-idf-nvs-partition-gen
+      ];
+    patches = [ ];
+  })
+  ).override {
+    rev = version;
+    sha256 = "sha256-w+xyva4t21STVtfYZOXY2xw6sDc2XvJXBZSx+wd1N6Y=";
+  };
+in
+stdenvNoCC.mkDerivation {
+  pname = "esp-idf-esp32c3-lib";
+  version = version;
+
+  dontUnpack = true; # start with empt src
+  dontConfigure = true;
+
+  # set environment variables for downstreams
+  setupHook = writeText "setup-hook.sh" ''
+    export ESP_IDF_DIR="${esp-idf-esp32c3'}"
+    export ESP_IDF_LIB="$1"
+  '';
+
+  buildInputs = [ esp-idf-esp32c3' git ];
+  propagatedBuildInputs = [ esp-idf-esp32c3' ];
+
+  buildPhase = ''
+    cp --no-preserve=mode,ownership -r "$IDF_PATH/examples/get-started/hello_world" ./
+    idf.py -C hello_world set-target esp32c3
+    idf.py -C hello_world build
+  '';
+  installPhase = ''
+    mkdir -p $out/esp32c3/bootloader
+    mv ./hello_world/build/esp-idf $out/esp32c3/
+    mv ./hello_world/build/bootloader/esp-idf $out/esp32c3/bootloader
+    mv ./hello_world/build/bootloader/config $out/esp32c3/bootloader
+  '';
+}

fips202/keccakf1600.c

@@ -31,8 +31,8 @@ Please refer to LowLevel.build for the exact list of other files it must be comb
 #define IS_BIG_ENDIAN      4321
 #define IS_LITTLE_ENDIAN   1234
 
-#if defined(__arm__)
-# ifdef __BIG_ENDIAN
+#if defined(__arm__) || defined(__riscv)
+# if defined(__BIG_ENDIAN) || defined(__ORDER_BIG_ENDIAN__)
 #  define PLATFORM_BYTE_ORDER IS_BIG_ENDIAN
 # else
 #  define PLATFORM_BYTE_ORDER IS_LITTLE_ENDIAN
@@ -152,7 +152,7 @@ void KeccakP1600_AddLanes(KeccakP1600_plain32_state *state, const unsigned char
                         | ((uint32_t)(laneAsBytes[5]) << 8)
                         | ((uint32_t)(laneAsBytes[6]) << 16)
                         | ((uint32_t)(laneAsBytes[7]) << 24);
-        uint32_t even, odd, temp, temp0, temp1;
+        uint32_t temp, temp0, temp1;
         uint32_t *stateAsHalfLanes = state->A;
         toBitInterleavingAndXOR(low, high, stateAsHalfLanes[lanePosition * 2 + 0], stateAsHalfLanes[lanePosition * 2 + 1], temp, temp0, temp1);
     }
@@ -203,7 +203,7 @@ static void KeccakP1600_ExtractLanes(const KeccakP1600_plain32_state *state, uns
     #else
     unsigned int lanePosition;
     for (lanePosition = 0; lanePosition < laneCount; lanePosition++) {
-        uint32_t *stateAsHalfLanes = state->A;
+        const uint32_t *stateAsHalfLanes = state->A;
         uint32_t low, high, temp, temp0, temp1;
         fromBitInterleaving(stateAsHalfLanes[lanePosition * 2], stateAsHalfLanes[lanePosition * 2 + 1], low, high, temp, temp0, temp1);
         uint8_t laneAsBytes[8];

flake.nix

@@ -6,25 +6,23 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
 
+    esp-dev = {
+      url = "github:mirrexagon/nixpkgs-esp-dev?rev=86a2bbe01fe0258887de7396af2a5eb0e37ac3be";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
     flake-parts = {
       url = "github:hercules-ci/flake-parts";
       inputs.nixpkgs-lib.follows = "nixpkgs";
     };
   };
 
-  outputs = inputs@{ flake-parts, ... }:
+  outputs = inputs@{ flake-parts, esp-dev, ... }:
     flake-parts.lib.mkFlake { inherit inputs; } {
       imports = [ ];
       systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
-      perSystem = { pkgs, ... }:
+      perSystem = { pkgs, system, ... }:
         let
-          libopencm3 = pkgs.callPackage ./libopencm3.nix {
-            targets = [ "stm32/f2" "stm32/f4" "stm32/f7" ];
-          };
-          mbed-os = pkgs.callPackage ./mbed-os.nix {
-            targets = [ "TARGET_MPS2_M3" "TARGET_MPS2_M4" "TARGET_MPS2_M7" ];
-          };
-
           core = builtins.attrValues {
             astyle = pkgs.astyle.overrideAttrs (old: rec {
               version = "3.4.13";
@@ -52,12 +50,22 @@
           };
 
           arm-pkgs = builtins.attrValues {
-            libopencm3 = libopencm3;
-            mbed-os = mbed-os;
+            libopencm3 = pkgs.callPackage ./libopencm3.nix {
+              targets = [ "stm32/f2" "stm32/f4" "stm32/f7" ];
+            };
+
+            mbed-os = pkgs.callPackage ./mbed-os.nix {
+              targets = [ "TARGET_MPS2_M3" "TARGET_MPS2_M4" "TARGET_MPS2_M7" ];
+            };
+
             inherit (pkgs)
               gcc-arm-embedded-13; # arm-gnu-toolchain-13.2.rel1
           };
 
+          riscv-pkgs = builtins.attrValues {
+            esp-idf-lib = pkgs.callPackage ./esp-idf-lib.nix { };
+          };
+
           wrapShell = mkShell: attrs:
             mkShell (attrs // {
               shellHook = ''
@@ -66,23 +74,26 @@
             });
         in
         {
+          _module.args = {
+            pkgs = import inputs.nixpkgs {
+              inherit system;
+              overlays = [ esp-dev.overlays.default ];
+            };
+          };
+
           devShells.default = wrapShell pkgs.mkShellNoCC {
-            packages = core ++ arm-pkgs ++ builtins.attrValues {
+            packages = core ++ arm-pkgs ++ riscv-pkgs ++ builtins.attrValues {
               inherit (pkgs)
                 direnv
                 nix-direnv
 
                 # debug dependencies
                 openocd; # 0.12.0
             };
-            OPENCM3_DIR = ''${libopencm3}'';
-            MBED_OS_DIR = ''${mbed-os}'';
           };
 
           devShells.ci = wrapShell pkgs.mkShellNoCC {
-            packages = core ++ arm-pkgs;
-            OPENCM3_DIR = ''${libopencm3}'';
-            MBED_OS_DIR = ''${mbed-os}'';
+            packages = core ++ arm-pkgs ++ riscv-pkgs;
           };
         };
       flake = {

hal/esp32-c3.ld

@@ -0,0 +1,68 @@
+/*SPDX-License-Identifier: MIT*/
+MEMORY {
+    irom   (x): org = 0x42000000, len = 0x400000
+    drom   (r): org = 0x3C000000, len = 0x400000
+    sram    (rw): org = 0x3FC80000, len = 0x50000
+    rtc_ram (rx): org = 0x50000000, len = 0x2000
+}
+
+ENTRY(_start)
+
+SECTIONS {
+  .header (READONLY): AT(0)
+  {
+    _iflash_start = .;
+    LONG(0xaedb041d)
+    LONG(0xaedb041d)
+  } > irom
+
+  .text.entry : {
+    KEEP(*(.text.entry))
+  } > irom
+
+  .text : {
+    *(.text .stub .text.* .gnu.linkonce.t.*)
+  } > irom
+
+  .iram : {
+    *(.iram .iram*)
+  } > irom
+
+  _iflash_end = .;
+  _iflash_size = _iflash_end - _iflash_start;
+
+  _dflash_start = ORIGIN(drom) + _iflash_size;
+  .rodata _dflash_start : AT(_iflash_size) {
+    *(.rodata .rodata* .srodata .srodata* .sdata2 .sdata2* .gnu.linkonce.r.*)
+  } > drom
+
+  _dflash_end = .;
+  _dflash_size = _dflash_end - _dflash_start;
+
+  .data ORIGIN(sram) : AT(_iflash_size + _dflash_size) {
+    _data_start = .;
+    *(.data .data* .gnu.linkonce.r.* .riscv.*)
+  } > sram
+
+  .sdata : {
+    _sdata_start = .;
+    *(.sdata .sdata.* .gnu.linkonce.s.*)
+  } > sram
+  _data_end = .;
+  _data_lma_start = ORIGIN(drom) + LOADADDR(.data);
+
+  .bss : {
+    _bss_start = .;
+    *(.bss .bss* .sbss .sbss* COMMON)
+    _bss_end = .;
+  } > sram
+
+  __global_pointer$ = _sdata_start + 0x800;
+
+  .stack : {
+    _stack_bottom = .;
+    _stack_top = ORIGIN(sram) + LENGTH(sram);
+    _stack_size_min = 0x4000;
+    ASSERT(_stack_bottom + _stack_size_min < _stack_top, "Error: no space for stack");
+  }
+}