make rom faster

.cargo/config.toml

@@ -36,6 +36,8 @@ rustflags = [
     "link-arg=-Tdefmt.x",
     "-C",
     "no-vectorize-loops",
+    "-C",
+    "target-cpu=cortex-m0plus",
 ]
 
 # This runner will make a UF2 file and then copy it to a mounted RP2040 in USB

Cargo.lock

@@ -455,6 +455,7 @@ checksum = "f4fa65b9284d974dad7a23bb72835c4ec85c0b540d86af7fc4098c88cff51d65"
 dependencies = [
  "cfg-if",
  "critical-section",
+ "defmt",
  "document-features",
  "embassy-time-driver",
  "embedded-hal 0.2.7",
@@ -655,9 +656,9 @@ dependencies = [
 
 [[package]]
 name = "hashbrown"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5419bdc4f6a9207fbeba6d11b604d481addf78ecd10c11ad51e76c2f6482748d"
+checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
 
 [[package]]
 name = "heapless"
@@ -687,9 +688,9 @@ checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
 
 [[package]]
 name = "indexmap"
-version = "2.12.0"
+version = "2.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6717a8d2a5a929a1a2eb43a12812498ed141a0bcfb7e8f7844fbdbe4303bba9f"
+checksum = "0ad4bb2b565bca0645f4d68c5c9af97fba094e9791da685bf83cb5f3ce74acf2"
 dependencies = [
  "equivalent",
  "hashbrown",
@@ -897,6 +898,7 @@ checksum = "5be167a7af36ee22fe3115051bc51f6e6c7054c9348e28deb4f49bd6f705a315"
 name = "picorom-rs"
 version = "0.1.0"
 dependencies = [
+ "cortex-m",
  "cortex-m-rt",
  "critical-section",
  "defmt",
@@ -904,6 +906,7 @@ dependencies = [
  "embassy-executor",
  "embassy-futures",
  "embassy-rp",
+ "embassy-time",
  "embassy-usb",
  "embedded-hal 1.0.0",
  "heapless 0.9.2",
@@ -1217,9 +1220,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "syn"
-version = "2.0.110"
+version = "2.0.111"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a99801b5bd34ede4cf3fc688c5919368fea4e4814a4664359503e6015b280aea"
+checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -2,6 +2,7 @@
 name = "picorom-rs"
 version = "0.1.0"
 edition = "2024"
+license = "MIT or Apache-2.0"
 
 [lints.clippy]
 pedantic = "warn"
@@ -14,6 +15,7 @@ test = false
 bench = false
 
 [dependencies]
+cortex-m = "0.7"
 cortex-m-rt = "0.7"
 embassy-rp = { version = "0.8", features = [
   "time-driver",
@@ -26,9 +28,12 @@ embassy-rp = { version = "0.8", features = [
 embassy-executor = { version = "0.9", features = [
   "defmt",
   "executor-thread",
-  "executor-interrupt",
   "arch-cortex-m",
 ] }
+embassy-time = { version = "0.5", features = [
+  "defmt",
+  "defmt-timestamp-uptime-tus",
+] }
 embassy-usb = { version = "0.5", default-features = false, features = [
   "defmt",
 ] }
@@ -51,7 +56,7 @@ codegen-units = 1
 debug = 2
 debug-assertions = true
 incremental = false
-opt-level = 3
+opt-level = 'z'
 overflow-checks = true
 
 # cargo build/run --release

assets/makerom.py

@@ -0,0 +1,13 @@
+code = bytearray([
+    0xa9, 0x42,
+    0x8d, 0x00, 0x40,
+    0xdb
+    ])
+
+rom = code + bytearray([0xEA] * (1024 * 32 - len(code)))
+
+rom[0x7FFC] = 0x00
+rom[0x7FFD] = 0x80
+
+with open("rom.bin", "wb") as bin_file:
+    bin_file.write(rom)

assets/test.S

@@ -0,0 +1,18 @@
+  .org 0x8000
+
+reset:
+  lda #0xff
+  sta 0x6002
+
+loop:
+  lda #0x55
+  sta 0x6000
+  
+  lda #0xaa
+  sta 0x6000
+
+  jmp reset
+
+  .org 0xfffc
+  .word reset
+  .word 0x0000

deny.toml

@@ -0,0 +1,232 @@
+# This template contains all of the possible sections and their default values
+
+# Note that all fields that take a lint level have these possible values:
+# * deny - An error will be produced and the check will fail
+# * warn - A warning will be produced, but the check will not fail
+# * allow - No warning or error will be produced, though in some cases a note
+# will be
+
+# The values provided in this template are the default values that will be used
+# when any section or field is not specified in your own configuration
+
+# Root options
+
+# The graph table configures how the dependency graph is constructed and thus
+# which crates the checks are performed against
+[graph]
+# If 1 or more target triples (and optionally, target_features) are specified,
+# only the specified targets will be checked when running `cargo deny check`.
+# This means, if a particular package is only ever used as a target specific
+# dependency, such as, for example, the `nix` crate only being used via the
+# `target_family = "unix"` configuration, that only having windows targets in
+# this list would mean the nix crate, as well as any of its exclusive
+# dependencies not shared by any other crates, would be ignored, as the target
+# list here is effectively saying which targets you are building for.
+targets = [
+  "thumbv6m-none-eabi",
+  # The triple can be any string, but only the target triples built in to
+  # rustc (as of 1.40) can be checked against actual config expressions
+  #"x86_64-unknown-linux-musl",
+  # You can also specify which target_features you promise are enabled for a
+  # particular target. target_features are currently not validated against
+  # the actual valid features supported by the target architecture.
+  #{ triple = "wasm32-unknown-unknown", features = ["atomics"] },
+]
+# When creating the dependency graph used as the source of truth when checks are
+# executed, this field can be used to prune crates from the graph, removing them
+# from the view of cargo-deny. This is an extremely heavy hammer, as if a crate
+# is pruned from the graph, all of its dependencies will also be pruned unless
+# they are connected to another crate in the graph that hasn't been pruned,
+# so it should be used with care. The identifiers are [Package ID Specifications]
+# (https://doc.rust-lang.org/cargo/reference/pkgid-spec.html)
+#exclude = []
+# If true, metadata will be collected with `--all-features`. Note that this can't
+# be toggled off if true, if you want to conditionally enable `--all-features` it
+# is recommended to pass `--all-features` on the cmd line instead
+all-features = false
+# If true, metadata will be collected with `--no-default-features`. The same
+# caveat with `all-features` applies
+no-default-features = false
+# If set, these feature will be enabled when collecting metadata. If `--features`
+# is specified on the cmd line they will take precedence over this option.
+#features = []
+
+# The output table provides options for how/if diagnostics are outputted
+[output]
+# When outputting inclusion graphs in diagnostics that include features, this
+# option can be used to specify the depth at which feature edges will be added.
+# This option is included since the graphs can be quite large and the addition
+# of features from the crate(s) to all of the graph roots can be far too verbose.
+# This option can be overridden via `--feature-depth` on the cmd line
+feature-depth = 1
+
+# This section is considered when running `cargo deny check advisories`
+# More documentation for the advisories section can be found here:
+# https://embarkstudios.github.io/cargo-deny/checks/advisories/cfg.html
+[advisories]
+# The path where the advisory databases are cloned/fetched into
+#db-path = "$CARGO_HOME/advisory-dbs"
+# The url(s) of the advisory databases to use
+#db-urls = ["https://github.com/rustsec/advisory-db"]
+# A list of advisory IDs to ignore. Note that ignored advisories will still
+# output a note when they are encountered.
+ignore = [
+  #"RUSTSEC-0000-0000",
+  #{ id = "RUSTSEC-0000-0000", reason = "you can specify a reason the advisory is ignored" },
+  #"a-crate-that-is-yanked@0.1.1", # you can also ignore yanked crate versions if you wish
+  #{ crate = "a-crate-that-is-yanked@0.1.1", reason = "you can specify why you are ignoring the yanked crate" },
+]
+# If this is true, then cargo deny will use the git executable to fetch advisory database.
+# If this is false, then it uses a built-in git library.
+# Setting this to true can be helpful if you have special authentication requirements that cargo-deny does not support.
+# See Git Authentication for more information about setting up git authentication.
+#git-fetch-with-cli = true
+
+# This section is considered when running `cargo deny check licenses`
+# More documentation for the licenses section can be found here:
+# https://embarkstudios.github.io/cargo-deny/checks/licenses/cfg.html
+[licenses]
+# List of explicitly allowed licenses
+# See https://spdx.org/licenses/ for list of possible licenses
+# [possible values: any SPDX 3.11 short identifier (+ optional exception)].
+allow = ["MIT", "Apache-2.0", "Unicode-3.0", "BSD-3-Clause"]
+# The confidence threshold for detecting a license from license text.
+# The higher the value, the more closely the license text must be to the
+# canonical license text of a valid SPDX license file.
+# [possible values: any between 0.0 and 1.0].
+confidence-threshold = 0.8
+# Allow 1 or more licenses on a per-crate basis, so that particular licenses
+# aren't accepted for every possible crate as with the normal allow list
+exceptions = [
+  # Each entry is the crate and version constraint, and its specific allow
+  # list
+  #{ allow = ["Zlib"], crate = "adler32" },
+]
+
+# Some crates don't have (easily) machine readable licensing information,
+# adding a clarification entry for it allows you to manually specify the
+# licensing information
+#[[licenses.clarify]]
+# The package spec the clarification applies to
+#crate = "ring"
+# The SPDX expression for the license requirements of the crate
+#expression = "MIT AND ISC AND OpenSSL"
+# One or more files in the crate's source used as the "source of truth" for
+# the license expression. If the contents match, the clarification will be used
+# when running the license check, otherwise the clarification will be ignored
+# and the crate will be checked normally, which may produce warnings or errors
+# depending on the rest of your configuration
+#license-files = [
+# Each entry is a crate relative path, and the (opaque) hash of its contents
+#{ path = "LICENSE", hash = 0xbd0eed23 }
+#]
+
+[licenses.private]
+# If true, ignores workspace crates that aren't published, or are only
+# published to private registries.
+# To see how to mark a crate as unpublished (to the official registry),
+# visit https://doc.rust-lang.org/cargo/reference/manifest.html#the-publish-field.
+ignore = false
+# One or more private registries that you might publish crates to, if a crate
+# is only published to private registries, and ignore is true, the crate will
+# not have its license(s) checked
+registries = [
+  #"https://sekretz.com/registry
+]
+
+# This section is considered when running `cargo deny check bans`.
+# More documentation about the 'bans' section can be found here:
+# https://embarkstudios.github.io/cargo-deny/checks/bans/cfg.html
+[bans]
+# Lint level for when multiple versions of the same crate are detected
+multiple-versions = "warn"
+# Lint level for when a crate version requirement is `*`
+wildcards = "allow"
+# The graph highlighting used when creating dotgraphs for crates
+# with multiple versions
+# * lowest-version - The path to the lowest versioned duplicate is highlighted
+# * simplest-path - The path to the version with the fewest edges is highlighted
+# * all - Both lowest-version and simplest-path are used
+highlight = "all"
+# The default lint level for `default` features for crates that are members of
+# the workspace that is being checked. This can be overridden by allowing/denying
+# `default` on a crate-by-crate basis if desired.
+workspace-default-features = "allow"
+# The default lint level for `default` features for external crates that are not
+# members of the workspace. This can be overridden by allowing/denying `default`
+# on a crate-by-crate basis if desired.
+external-default-features = "allow"
+# List of crates that are allowed. Use with care!
+allow = [
+  #"ansi_term@0.11.0",
+  #{ crate = "ansi_term@0.11.0", reason = "you can specify a reason it is allowed" },
+]
+# List of crates to deny
+deny = [
+  #"ansi_term@0.11.0",
+  #{ crate = "ansi_term@0.11.0", reason = "you can specify a reason it is banned" },
+  # Wrapper crates can optionally be specified to allow the crate when it
+  # is a direct dependency of the otherwise banned crate
+  #{ crate = "ansi_term@0.11.0", wrappers = ["this-crate-directly-depends-on-ansi_term"] },
+]
+
+# List of features to allow/deny
+# Each entry the name of a crate and a version range. If version is
+# not specified, all versions will be matched.
+#[[bans.features]]
+#crate = "reqwest"
+# Features to not allow
+#deny = ["json"]
+# Features to allow
+#allow = [
+#    "rustls",
+#    "__rustls",
+#    "__tls",
+#    "hyper-rustls",
+#    "rustls",
+#    "rustls-pemfile",
+#    "rustls-tls-webpki-roots",
+#    "tokio-rustls",
+#    "webpki-roots",
+#]
+# If true, the allowed features must exactly match the enabled feature set. If
+# this is set there is no point setting `deny`
+#exact = true
+
+# Certain crates/versions that will be skipped when doing duplicate detection.
+skip = [
+  #"ansi_term@0.11.0",
+  #{ crate = "ansi_term@0.11.0", reason = "you can specify a reason why it can't be updated/removed" },
+]
+# Similarly to `skip` allows you to skip certain crates during duplicate
+# detection. Unlike skip, it also includes the entire tree of transitive
+# dependencies starting at the specified crate, up to a certain depth, which is
+# by default infinite.
+skip-tree = [
+  #"ansi_term@0.11.0", # will be skipped along with _all_ of its direct and transitive dependencies
+  #{ crate = "ansi_term@0.11.0", depth = 20 },
+]
+
+# This section is considered when running `cargo deny check sources`.
+# More documentation about the 'sources' section can be found here:
+# https://embarkstudios.github.io/cargo-deny/checks/sources/cfg.html
+[sources]
+# Lint level for what to happen when a crate from a crate registry that is not
+# in the allow list is encountered
+unknown-registry = "warn"
+# Lint level for what to happen when a crate from a git repository that is not
+# in the allow list is encountered
+unknown-git = "warn"
+# List of URLs for allowed crate registries. Defaults to the crates.io index
+# if not specified. If it is specified but empty, no registries are allowed.
+allow-registry = ["https://github.com/rust-lang/crates.io-index"]
+# List of URLs for allowed Git repositories
+allow-git = []
+
+[sources.allow-org]
+# github.com organizations to allow git sources for
+github = []
+# gitlab.com organizations to allow git sources for
+gitlab = []
+# bitbucket.org organizations to allow git sources for
+bitbucket = []

memory.x

@@ -15,7 +15,7 @@ SECTIONS {
     } > BOOT2
 
     /* Initial ROM data */
-    .romdata ORIGIN(ROM) :
+    .romdata ORIGIN(ROM) (NOLOAD) :
     {
         KEEP(*(.romdata*));
     } > ROM

src/main.rs

@@ -12,23 +12,25 @@ mod serial;
 
 use core::{
     mem::MaybeUninit,
+    ptr::addr_of_mut,
     sync::atomic::{AtomicU8, Ordering},
     task::Poll,
 };
 
 use defmt_rtt as _;
-use embassy_executor::{InterruptExecutor, Spawner, task};
+use embassy_executor::{Spawner, task};
-use embassy_futures::{poll_once, yield_now};
+use embassy_futures::poll_once;
 use embassy_rp::{
     bind_interrupts,
     clocks::ClockConfig,
     flash::{self, FLASH_BASE, Flash},
     gpio::{Drive, Level, Output, SlewRate},
-    interrupt::{self, InterruptExt, Priority},
+    multicore::{Stack, spawn_core1},
     peripherals::{FLASH, PIO0, USB},
     pio::{self, Direction, Pio, ShiftConfig, ShiftDirection, StateMachine, program::pio_asm},
     usb::{self, Driver},
 };
+use embassy_time::Timer;
 use embassy_usb::{
     UsbDevice,
     class::cdc_acm::{self, CdcAcmClass},
@@ -45,6 +47,7 @@ const ROM_SIZE: usize = 32 * 1024;
 const FLASH_SIZE: usize = 2 * 1024 * 1024;
 
 static ROM_DATA: [AtomicU8; ROM_SIZE] = [const { AtomicU8::new(0) }; ROM_SIZE];
+static mut CORE1_STACK: Stack<4096> = Stack::new();
 
 #[unsafe(link_section = ".romdata")]
 #[used]
@@ -55,17 +58,10 @@ bind_interrupts!(struct Irqs {
     USBCTRL_IRQ => usb::InterruptHandler<USB>;
 });
 
-static EXECUTOR_HIGH: InterruptExecutor = InterruptExecutor::new();
-
-#[embassy_rp::interrupt]
-unsafe fn SWI_IRQ_0() {
-    unsafe { EXECUTOR_HIGH.on_interrupt() }
-}
-
 #[embassy_executor::main]
 async fn main(spawner: Spawner) -> ! {
     let config =
-        embassy_rp::config::Config::new(defmt::unwrap!(ClockConfig::system_freq(133_000_000)));
+        embassy_rp::config::Config::new(defmt::unwrap!(ClockConfig::system_freq(200_000_000)));
     let p = embassy_rp::init(config);
 
     let led = unsafe { p.PIN_25.clone_unchecked() };
@@ -230,6 +226,16 @@ async fn main(spawner: Spawner) -> ! {
     sm3.set_config(&cfg);
     sm3.set_enable(true);
 
+    spawn_core1(
+        p.CORE1,
+        unsafe { &mut *addr_of_mut!(CORE1_STACK) },
+        move || core1_loop(sm0, sm3),
+    );
+
+    // enable the rx not empty interrupt for sm3 on interrupt line 0
+    // let pio = PIO0;
+    // pio.irqs(0).inte().modify(|m| m.set_sm3_rxnempty(true));
+
     let driver = Driver::new(p.USB, Irqs);
 
     let config = {
@@ -263,13 +269,6 @@ async fn main(spawner: Spawner) -> ! {
 
     let usb = builder.build();
 
-    interrupt::PIO0_IRQ_0.set_priority(Priority::P0);
-    interrupt::SWI_IRQ_0.set_priority(Priority::P1);
-    interrupt::USBCTRL_IRQ.set_priority(Priority::P3);
-
-    let int_spawner = EXECUTOR_HIGH.start(interrupt::SWI_IRQ_0);
-    int_spawner.must_spawn(pio_task(sm0, sm3));
-
     spawner.must_spawn(usb_task(usb));
 
     let mut led = Output::new(led, Level::Low);
@@ -279,7 +278,7 @@ async fn main(spawner: Spawner) -> ! {
             led.set_low();
             class.wait_connection().await;
             while !class.rts() {
-                yield_now().await;
+                Timer::after_micros(1).await;
             }
             defmt::info!("USB Connected");
             led.set_high();
@@ -298,7 +297,7 @@ async fn main(spawner: Spawner) -> ! {
                         break 'outer;
                     }
                     Poll::Pending => {
-                        yield_now().await;
+                        Timer::after_micros(1).await;
                         continue;
                     }
                 };
@@ -320,6 +319,23 @@ async fn main(spawner: Spawner) -> ! {
     }
 }
 
+fn core1_loop<const N1: usize, const N2: usize>(
+    mut data_sm: StateMachine<'_, impl pio::Instance, N1>,
+    mut address_sm: StateMachine<'_, impl pio::Instance, N2>,
+) -> ! {
+    loop {
+        let address = loop {
+            if let Some(address) = address_sm.rx().try_pull() {
+                break address;
+            }
+        };
+        let address = (address & 0x7fff) as u16;
+        let data = ROM_DATA[usize::from(address)].load(Ordering::Relaxed);
+        defmt::debug!("replying with {:#04x} @ {:#06x}", data, address);
+        data_sm.tx().push(u32::from(data));
+    }
+}
+
 #[task]
 async fn usb_task(mut usb: UsbDevice<'static, Driver<'static, USB>>) -> ! {
     usb.run().await