feat: verification

Author: RossComputerGuy

Cargo.lock

@@ -1,5 +1,5 @@
 [workspace]
-members = ["crates/aegis-desc", "crates/aegis-pack", "crates/aegis-sim"]
+members = ["crates/aegis-ip", "crates/aegis-pack", "crates/aegis-sim"]
 resolver = "2"
 
 [workspace.package]

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
-name = "aegis-desc"
+name = "aegis-ip"
 version.workspace = true
 edition.workspace = true
-description = "Aegis FPGA device descriptor types generated from JSON Schema"
+description = "Aegis FPGA device descriptor types and tile config bit layout"
 
 [dependencies]
 serde = { workspace = true }

crates/aegis-desc/Cargo.toml crates/aegis-ip/Cargo.tomlcrates/aegis-desc/Cargo.toml renamed to crates/aegis-ip/Cargo.toml

@@ -1,9 +1,18 @@
-use typify::import_types;
+/// Device descriptor types generated from the JSON Schema.
+pub mod desc {
+    use typify::import_types;
+    import_types!(schema = "../../ip/data/descriptor.schema.json");
+}
+
+pub use desc::*;
+
+#[allow(unused_imports)]
+pub use tile_bits::TileConfig;
 
-import_types!(schema = "../../ip/data/descriptor.schema.json");
+pub mod tile_bits;
 
 #[cfg(test)]
-mod tests {
+mod desc_tests {
     use std::num::NonZero;
 
     use super::*;

crates/aegis-desc/src/lib.rs crates/aegis-ip/src/lib.rscrates/aegis-desc/src/lib.rs renamed to crates/aegis-ip/src/lib.rs

@@ -0,0 +1,247 @@
+//! Shared tile config bit layout for Aegis FPGA.
+//!
+//! This crate is the single source of truth for the tile configuration
+//! bitstream layout. Both the packer (aegis-pack) and simulator (aegis-sim)
+//! depend on this crate to ensure their bit layouts are identical.
+//!
+//! Layout for T tracks:
+//!   [17:0]              CLB config (16 LUT init + 1 FF enable + 1 carry mode)
+//!   [18..18+4*ISW-1]    input mux sel0..sel3 (ISW = input_sel_width(T))
+//!   [18+4*ISW..]        per-track output: 4 dirs × T tracks × (1 en + 3 sel)
+//!
+//! For T=1: 46 bits (backward compatible with original layout)
+//! For T=4: 102 bits
+
+// --- Fixed offsets (track-independent) ---
+
+pub const LUT_INIT: usize = 0;
+pub const LUT_INIT_WIDTH: usize = 16;
+pub const FF_ENABLE: usize = 16;
+pub const CARRY_MODE: usize = 17;
+pub const INPUT_SEL_BASE: usize = 18;
+
+// --- Output mux select values ---
+
+pub const OUT_MUX_NORTH: u64 = 0;
+pub const OUT_MUX_EAST: u64 = 1;
+pub const OUT_MUX_SOUTH: u64 = 2;
+pub const OUT_MUX_WEST: u64 = 3;
+pub const OUT_MUX_CLB: u64 = 4;
+
+pub const OUTPUT_SEL_WIDTH: usize = 3;
+
+// --- Parametric layout functions ---
+
+/// Width of input select field for T tracks.
+/// Encodes: N0..N(T-1), E0..E(T-1), S0..S(T-1), W0..W(T-1), CLB_OUT, const0, const1
+pub fn input_sel_width(tracks: usize) -> usize {
+    let n = 4 * tracks + 3;
+    (usize::BITS - (n - 1).leading_zeros()) as usize
+}
+
+/// Bit offset of input sel[idx] for T tracks.
+pub fn input_sel_offset(idx: usize, tracks: usize) -> usize {
+    INPUT_SEL_BASE + idx * input_sel_width(tracks)
+}
+
+/// Base offset of the per-track output section.
+pub fn output_base(tracks: usize) -> usize {
+    INPUT_SEL_BASE + 4 * input_sel_width(tracks)
+}
+
+/// Enable bit offset for output (dir, track).
+pub fn output_en(dir: usize, track: usize, tracks: usize) -> usize {
+    output_base(tracks) + (dir * tracks + track) * 4
+}
+
+/// Select field offset for output (dir, track). 3 bits wide.
+pub fn output_sel(dir: usize, track: usize, tracks: usize) -> usize {
+    output_base(tracks) + (dir * tracks + track) * 4 + 1
+}
+
+/// Total tile config width for T tracks.
+pub fn tile_config_width(tracks: usize) -> usize {
+    18 + 4 * input_sel_width(tracks) + 4 * tracks * 4
+}
+
+/// Input mux select value for direction + track.
+pub fn mux_dir_track(dir: usize, track: usize, tracks: usize) -> u64 {
+    (dir * tracks + track) as u64
+}
+
+/// Input mux select value for CLB output.
+pub fn mux_clb_out(tracks: usize) -> u64 {
+    (4 * tracks) as u64
+}
+
+/// Input mux select value for constant 0.
+pub fn mux_const0(tracks: usize) -> u64 {
+    (4 * tracks + 1) as u64
+}
+
+/// Input mux select value for constant 1.
+pub fn mux_const1(tracks: usize) -> u64 {
+    (4 * tracks + 2) as u64
+}
+
+// --- Bitstream read/write helpers ---
+
+/// Set a single bit in a bitstream buffer.
+pub fn set_bit(bits: &mut [u8], offset: usize) {
+    bits[offset / 8] |= 1 << (offset % 8);
+}
+
+/// Clear bits at a given offset and width.
+pub fn clear_bits(bits: &mut [u8], offset: usize, width: usize) {
+    for i in 0..width {
+        bits[(offset + i) / 8] &= !(1 << ((offset + i) % 8));
+    }
+}
+
+/// Write a value into the bitstream at a given bit offset and width.
+pub fn write_bits(bits: &mut [u8], offset: usize, value: u64, width: usize) {
+    clear_bits(bits, offset, width);
+    for i in 0..width {
+        if value & (1 << i) != 0 {
+            set_bit(bits, offset + i);
+        }
+    }
+}
+
+/// Read a value from the bitstream at a given bit offset and width.
+pub fn read_bits(bits: &[u8], offset: usize, width: usize) -> u64 {
+    let mut val = 0u64;
+    for i in 0..width {
+        let byte_idx = (offset + i) / 8;
+        let bit_idx = (offset + i) % 8;
+        if byte_idx < bits.len() && bits[byte_idx] & (1 << bit_idx) != 0 {
+            val |= 1 << i;
+        }
+    }
+    val
+}
+
+/// Read a single bit from the bitstream.
+pub fn read_bit(bits: &[u8], offset: usize) -> bool {
+    let byte_idx = offset / 8;
+    let bit_idx = offset % 8;
+    byte_idx < bits.len() && bits[byte_idx] & (1 << bit_idx) != 0
+}
+
+// --- Decoded tile configuration ---
+
+/// Decoded tile configuration with per-track output muxes.
+#[derive(Clone, Debug, PartialEq)]
+pub struct TileConfig {
+    pub lut_init: u16,
+    pub ff_enable: bool,
+    pub carry_mode: bool,
+    pub sel: [u8; 4],
+    pub en_out: Vec<Vec<bool>>,
+    pub sel_out: Vec<Vec<u8>>,
+}
+
+impl TileConfig {
+    pub fn default_for(tracks: usize) -> Self {
+        Self {
+            lut_init: 0,
+            ff_enable: false,
+            carry_mode: false,
+            sel: [0; 4],
+            en_out: vec![vec![false; tracks]; 4],
+            sel_out: vec![vec![0; tracks]; 4],
+        }
+    }
+
+    pub fn has_any_config(&self) -> bool {
+        self.lut_init != 0
+            || self.ff_enable
+            || self.carry_mode
+            || self.en_out.iter().any(|d| d.iter().any(|&e| e))
+            || self.sel.iter().any(|&s| s != 0)
+    }
+
+    /// Encode this tile config into a bitstream buffer at the given offset.
+    pub fn encode(&self, bits: &mut [u8], bit_offset: usize, tracks: usize) {
+        write_bits(
+            bits,
+            bit_offset + LUT_INIT,
+            self.lut_init as u64,
+            LUT_INIT_WIDTH,
+        );
+        if self.ff_enable {
+            set_bit(bits, bit_offset + FF_ENABLE);
+        }
+        if self.carry_mode {
+            set_bit(bits, bit_offset + CARRY_MODE);
+        }
+        let isw = input_sel_width(tracks);
+        for i in 0..4 {
+            write_bits(
+                bits,
+                bit_offset + input_sel_offset(i, tracks),
+                self.sel[i] as u64,
+                isw,
+            );
+        }
+        for dir in 0..4 {
+            for t in 0..tracks {
+                if dir < self.en_out.len() && t < self.en_out[dir].len() && self.en_out[dir][t] {
+                    set_bit(bits, bit_offset + output_en(dir, t, tracks));
+                }
+                if dir < self.sel_out.len() && t < self.sel_out[dir].len() {
+                    write_bits(
+                        bits,
+                        bit_offset + output_sel(dir, t, tracks),
+                        self.sel_out[dir][t] as u64,
+                        OUTPUT_SEL_WIDTH,
+                    );
+                }
+            }
+        }
+    }
+
+    /// Decode a tile config from bitstream bits at the given offset.
+    pub fn decode(bitstream: &[u8], bit_offset: usize, tracks: usize) -> Self {
+        let isw = input_sel_width(tracks);
+
+        let sel = std::array::from_fn(|i| {
+            read_bits(bitstream, bit_offset + input_sel_offset(i, tracks), isw) as u8
+        });
+
+        let en_out = (0..4)
+            .map(|d| {
+                (0..tracks)
+                    .map(|t| read_bit(bitstream, bit_offset + output_en(d, t, tracks)))
+                    .collect()
+            })
+            .collect();
+
+        let sel_out = (0..4)
+            .map(|d| {
+                (0..tracks)
+                    .map(|t| {
+                        read_bits(
+                            bitstream,
+                            bit_offset + output_sel(d, t, tracks),
+                            OUTPUT_SEL_WIDTH,
+                        ) as u8
+                    })
+                    .collect()
+            })
+            .collect();
+
+        TileConfig {
+            lut_init: read_bits(bitstream, bit_offset + LUT_INIT, LUT_INIT_WIDTH) as u16,
+            ff_enable: read_bit(bitstream, bit_offset + FF_ENABLE),
+            carry_mode: read_bit(bitstream, bit_offset + CARRY_MODE),
+            sel,
+            en_out,
+            sel_out,
+        }
+    }
+}
+
+#[cfg(test)]
+#[path = "tile_bits_tests.rs"]
+mod tests;