build at attiny85-blink project

Cargo.lock

@@ -128,6 +128,13 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "attiny85-blink"
+version = "0.1.0"
+dependencies = [
+ "avr_delay",
+]
+
 [[package]]
 name = "autocfg"
 version = "0.1.8"
@@ -143,6 +150,23 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "avr-config"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "abb2276df19ea0f25741658d218861b8a24d78eaf926127eb2384f0927f9ab9f"
+dependencies = [
+ "const_env--value",
+]
+
+[[package]]
+name = "avr_delay"
+version = "0.4.2"
+source = "git+https://github.com/avr-rust/delay/?rev=0.4.2#849918a8dfb2f6211787bd8ff69c4083d685cf54"
+dependencies = [
+ "avr-config",
+]
+
 [[package]]
 name = "backtrace"
 version = "0.3.69"
@@ -436,6 +460,26 @@ version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "28c122c3980598d243d63d9a704629a2d748d101f278052ff068be5a4423ab6f"
 
+[[package]]
+name = "const_env--value"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ade503a5095050a5bf3feb8ae71842fb49dfc4af01dd613beb4f00bb7144645"
+dependencies = [
+ "const_env_impl--value",
+]
+
+[[package]]
+name = "const_env_impl--value"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a046e06596453266c54d3eb790813fd047494fc1d04d5077fba628bf84e1b83a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "cookie"
 version = "0.17.0"

Cargo.toml

@@ -1,5 +1,6 @@
 [workspace]
 members = [
+    "attiny85-blink",
     "changeset",
     "config",
     "config-derive",

attiny85-blink/.cargo/config.toml

@@ -0,0 +1,5 @@
+[build]
+target = "../avr-attiny85.json"
+
+[unstable]
+build-std = ["core"]

attiny85-blink/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "attiny85-blink"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+avr_delay = { git = "https://github.com/avr-rust/delay/", rev = "0.4.2" }
+

attiny85-blink/rust-toolchain

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "nightly"
+profile = "minimal"

attiny85-blink/src/main.rs

@@ -0,0 +1,65 @@
+#![no_std]
+#![no_main]
+
+use avr_delay::delay_ms;
+
+// PORTB address is 0x38 (documentation says 0x18)
+// DDRB address is 0x37 (documentation says 0x17)
+// PINB address is 0x36 (documentation says 0x16)
+//
+// Whenever accessing a pin/port via the LD and ST instructions, add 0x20 to each address. This is
+// hidden in the attiny85 datasheet in section 5.4. Section 5.2 shows a memory map in which the I/O
+// registers start at address 0x20. Before that are the normal general purpose registers.
+//
+// Writing to a bit to a register means setting up a write mask, then using
+// `core::ptr::write_volatile`. Watch for the `ops::Bit...` traits to help outwith bit operations.
+
+trait Register {
+    type T;
+    const ADDRESS: *mut Self::T;
+
+    fn write(value: Self::T) {
+        unsafe {
+            core::ptr::write_volatile(Self::ADDRESS, value);
+        }
+    }
+
+    fn read() -> Self::T {
+        unsafe { core::ptr::read_volatile(Self::ADDRESS) }
+    }
+}
+
+#[allow(non_camel_case_types)]
+pub struct PINB;
+
+impl Register for PINB {
+    type T = u8;
+    const ADDRESS: *mut u8 = 0x36 as *mut u8;
+}
+
+#[allow(non_camel_case_types)]
+pub struct DDRB;
+
+impl Register for DDRB {
+    type T = u8;
+    const ADDRESS: *mut u8 = 0x37 as *mut u8;
+}
+
+#[allow(non_camel_case_types)]
+pub struct PORTB;
+
+impl Register for PORTB {
+    type T = u8;
+    const ADDRESS: *mut u8 = 0x38 as *mut u8;
+}
+
+#[no_mangle]
+pub extern "C" fn main() {
+    DDRB::write(0x01);
+    loop {
+        PORTB::write(0x01);
+        delay_ms(500);
+        PORTB::write(0x00);
+        delay_ms(500);
+    }
+}

avr-atmega328p.json

@@ -0,0 +1,31 @@
+{
+  "arch": "avr",
+  "cpu": "atmega328p",
+  "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
+  "env": "",
+  "executables": true,
+  "linker": "avr-gcc",
+  "linker-flavor": "gcc",
+  "linker-is-gnu": true,
+  "llvm-target": "avr-unknown-unknown",
+  "os": "unknown",
+  "position-independent-executables": false,
+  "exe-suffix": ".elf",
+  "eh-frame-header": false,
+  "pre-link-args": {
+    "gcc": [
+      "-Os",
+      "-mmcu=atmega328p"
+    ]
+  },
+  "late-link-args": {
+    "gcc": [
+      "-lc",
+      "-lgcc"
+    ]
+  },
+  "target-c-int-width": "16",
+  "target-endian": "little",
+  "target-pointer-width": "16",
+  "vendor": "unknown"
+}

avr-atmega32u4.json

@@ -0,0 +1,31 @@
+{
+  "arch": "avr",
+  "cpu": "atmega32u4",
+  "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
+  "env": "",
+  "executables": true,
+  "linker": "avr-gcc",
+  "linker-flavor": "gcc",
+  "linker-is-gnu": true,
+  "llvm-target": "avr-unknown-unknown",
+  "os": "unknown",
+  "position-independent-executables": false,
+  "exe-suffix": ".elf",
+  "eh-frame-header": false,
+  "pre-link-args": {
+    "gcc": [
+      "-Os",
+      "-mmcu=atmega32u4"
+    ]
+  },
+  "late-link-args": {
+    "gcc": [
+      "-lc",
+      "-lgcc"
+    ]
+  },
+  "target-c-int-width": "16",
+  "target-endian": "little",
+  "target-pointer-width": "16",
+  "vendor": "unknown"
+}

avr-attiny85.json

@@ -0,0 +1,25 @@
+{
+  "arch": "avr",
+  "atomic-cas": false,
+  "cpu": "attiny85",
+  "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
+  "eh-frame-header": false,
+  "exe-suffix": ".elf",
+  "executables": true,
+  "late-link-args": {
+    "gcc": [
+      "-lgcc"
+    ]
+  },
+  "linker": "avr-gcc",
+  "llvm-target": "avr-unknown-unknown",
+  "max-atomic-width": 8,
+  "no-default-libraries": false,
+  "pre-link-args": {
+    "gcc": [
+      "-mmcu=attiny85"
+    ]
+  },
+  "target-c-int-width": "16",
+  "target-pointer-width": "16"
+}

flake.lock

@@ -64,6 +64,21 @@
         "type": "indirect"
       }
     },
+    "nixpkgs-22-11": {
+      "locked": {
+        "lastModified": 1688392541,
+        "narHash": "sha256-lHrKvEkCPTUO+7tPfjIcb7Trk6k31rz18vkyqmkeJfY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "ea4c80b39be4c09702b0cb3b42eab59e2ba4f24b",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-22.11",
+        "type": "indirect"
+      }
+    },
     "nixpkgs_2": {
       "locked": {
         "lastModified": 1654275867,
@@ -119,6 +134,7 @@
     "root": {
       "inputs": {
         "nixpkgs": "nixpkgs",
+        "nixpkgs-22-11": "nixpkgs-22-11",
         "pkgs-cargo2nix": "pkgs-cargo2nix",
         "typeshare": "typeshare",
         "unstable": "unstable"

flake.nix

@@ -3,12 +3,13 @@
 
   inputs = {
     nixpkgs.url = "nixpkgs/nixos-23.05";
+    nixpkgs-22-11.url = "nixpkgs/nixos-22.11";
     unstable.url = "nixpkgs/nixos-unstable";
     pkgs-cargo2nix.url = "github:cargo2nix/cargo2nix";
     typeshare.url = "github:1Password/typeshare";
   };
 
-  outputs = { self, nixpkgs, unstable, pkgs-cargo2nix, typeshare, ... }:
+  outputs = { self, nixpkgs, nixpkgs-22-11, unstable, pkgs-cargo2nix, typeshare, ... }:
     let 
       version = builtins.string 0 8 self.lastModifiedDate;
       supportedSystems = [ "x86_64-linux" ];
@@ -17,12 +18,17 @@
       devShell."x86_64-linux" =
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
+          pkgs-22-11 = import nixpkgs-22-11 { system = "x86_64-linux"; };
           pkgs-unstable = import unstable { system = "x86_64-linux"; };
           cargo2nix = pkgs-cargo2nix.packages."x86_64-linux";
+          avr = pkgs-22-11.pkgsCross.avr;
         in
         pkgs.mkShell {
           name = "ld-tools-devshell";
           buildInputs = [
+            avr.buildPackages.gcc
+            avr.buildPackages.avrdude
+            avr.avrlibc
             pkgs.libadwaita
             pkgs.clang
             pkgs.entr