Add support for the PicoCalc platform

Cargo.toml

@@ -11,6 +11,12 @@ heapless = "0.9.2"
 log = "0.4.29"
 cortex-m-rt = "0.7.5"
 static_cell = "2.1.1"
+embedded-hal = "1.0.0"
+embedded-graphics = "0.8.1"
+defmt = "1"
+defmt-rtt = "1"
+panic-probe = "1"
+rp235x-hal = "0.3"
 
 [profile.dev]
 debug = 1

flake.nix

@@ -9,6 +9,7 @@
       systems = [
         "x86_64-linux"
         "aarch64-linux"
+        "aarch64-darwin"
       ];
 
       forAllSystems = nixpkgs.lib.genAttrs systems;
@@ -23,6 +24,7 @@
             pkgs.probe-rs
             pkgs.flip-link
             pkgs.gcc-arm-embedded-14
+            pkgs.picotool
           ];
 
         };

platforms/cmforth-picocalc/.cargo/config.toml

@@ -0,0 +1,32 @@
+[target.thumbv8m.main-none-eabihf]
+# Choose a default "cargo run" tool (see README for more info)
+# - `probe-rs` provides flashing and defmt via a hardware debugger, and stack unwind on panic
+# - `picotool` loads an elf, skipping unchanged flash sectors, verify it, and execute it
+#runner = "probe-rs run --chip RP235x --protocol swd"
+# runner = "picotool load -f -u -v -x -t elf"
+runner = "probe-rs run --chip RP235x --protocol swd"
+
+linker = "flip-link"
+
+# Pass some extra options to rustc, some of which get passed on to the linker.
+#
+# * linker argument --nmagic turns off page alignment of sections (which saves
+#   flash space)
+# * linker argument -Tlink.x tells the linker to use link.x as a linker script.
+#   This is usually provided by the cortex-m-rt crate, and by default the
+#   version in that crate will include a file called `memory.x` which describes
+#   the particular memory layout for your specific chip.
+# * linker argument -Tdefmt.x also tells the linker to use `defmt.x` as a
+#   secondary linker script. This is required to make defmt_rtt work.
+rustflags = [
+    "-C", "link-arg=--nmagic",
+    "-C", "link-arg=-Tlink.x",
+    "-C", "link-arg=-Tdefmt.x",
+    "-C", "target-cpu=cortex-m33",
+]
+
+[build]
+target = "thumbv8m.main-none-eabihf"
+
+[env]
+DEFMT_LOG = "debug"

platforms/cmforth-picocalc/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "cmforth-picocalc"
+version = "0.1.0"
+edition = "2024"
+license = "MIT OR Apache-2.0"
+
+[dependencies]
+cmforth.workspace = true
+cortex-m-rt.workspace = true
+cortex-m.workspace = true
+defmt-rtt.workspace = true
+defmt.workspace = true
+embedded-graphics.workspace = true
+embedded-hal.workspace = true
+heapless.workspace = true
+panic-probe = { workspace = true, features = ["print-defmt"] }
+rp235x-hal = { workspace = true, features = [
+    "rt",
+    "critical-section-impl",
+    "binary-info",
+] }
+static_cell.workspace = true

platforms/cmforth-picocalc/build.rs

@@ -0,0 +1,16 @@
+use std::{env, fs::File, io::Write, path::Path};
+
+fn main() {
+    println!("cargo:rerun-if-changed=memory.x");
+    println!("cargo:rerun-if-changed=build.rs");
+    copy_linker_script()
+}
+
+fn copy_linker_script() {
+    let out_dir = env::var("OUT_DIR").expect("No OUT_DIR");
+    let dest_path = Path::new(&out_dir);
+    let mut f = File::create(dest_path.join("memory.x")).unwrap();
+    f.write_all(include_bytes!("memory.x")).unwrap();
+
+    println!("cargo:rustc-link-search={}", dest_path.display());
+}

platforms/cmforth-picocalc/memory.x

@@ -0,0 +1,75 @@
+MEMORY {
+    /*
+     * The RP2350 has either external or internal flash.
+     *
+     * 2 MiB is a safe default here, although a Pico 2 has 4 MiB.
+     */
+    FLASH : ORIGIN = 0x10000000, LENGTH = 2048K
+    /*
+     * RAM consists of 8 banks, SRAM0-SRAM7, with a striped mapping.
+     * This is usually good for performance, as it distributes load on
+     * those banks evenly.
+     */
+    RAM : ORIGIN = 0x20000000, LENGTH = 512K
+    /*
+     * RAM banks 8 and 9 use a direct mapping. They can be used to have
+     * memory areas dedicated for some specific job, improving predictability
+     * of access times.
+     * Example: Separate stacks for core0 and core1.
+     */
+    SRAM4 : ORIGIN = 0x20080000, LENGTH = 4K
+    SRAM5 : ORIGIN = 0x20081000, LENGTH = 4K
+}
+
+SECTIONS {
+    /* ### Boot ROM info
+     *
+     * Goes after .vector_table, to keep it in the first 4K of flash
+     * where the Boot ROM (and picotool) can find it
+     */
+    .start_block : ALIGN(4)
+    {
+        __start_block_addr = .;
+        KEEP(*(.start_block));
+        KEEP(*(.boot_info));
+    } > FLASH
+
+} INSERT AFTER .vector_table;
+
+/* move .text to start /after/ the boot info */
+_stext = ADDR(.start_block) + SIZEOF(.start_block);
+
+SECTIONS {
+    /* ### Picotool 'Binary Info' Entries
+     *
+     * Picotool looks through this block (as we have pointers to it in our
+     * header) to find interesting information.
+     */
+    .bi_entries : ALIGN(4)
+    {
+        /* We put this in the header */
+        __bi_entries_start = .;
+        /* Here are the entries */
+        KEEP(*(.bi_entries));
+        /* Keep this block a nice round size */
+        . = ALIGN(4);
+        /* We put this in the header */
+        __bi_entries_end = .;
+    } > FLASH
+} INSERT AFTER .text;
+
+SECTIONS {
+    /* ### Boot ROM extra info
+     *
+     * Goes after everything in our program, so it can contain a signature.
+     */
+    .end_block : ALIGN(4)
+    {
+        __end_block_addr = .;
+        KEEP(*(.end_block));
+    } > FLASH
+
+} INSERT AFTER .uninit;
+
+PROVIDE(start_to_end = __end_block_addr - __start_block_addr);
+PROVIDE(end_to_start = __start_block_addr - __end_block_addr);