Replace PAC dependency w/ new internal VI module (#1)

A new internal definition of VI registers, related types, and
documenting comments replaces the dependency on n64-pac. This
also removes a duplicate transitive dependency (proc-bitfield).

Primary motivations for this change:
- New documenting comments and links to reference material on each
   register, bitfield, and enum
- Enable additional types and macros to improve ergonomics
- Fewer external dependencies

Most of the time spent has been learning about each VI field and analog
television in general; much less time has been spent on the ergonomics
of the interface, which have gotten slightly worse. Future types, macros,
and defaults (e.g. for NTSC constants) are part of the growing todo list.

game/Cargo.toml

@@ -13,4 +13,3 @@ path = "src/bin/main.rs"
 
 [dependencies]
 kernel = { path = "../kernel" }
-n64-pac = "0.3.3"

game/src/bin/main.rs

@@ -13,8 +13,7 @@ use core::panic::PanicInfo;
 
 use kernel::dev::rdp::interface::RDPInterface;
 use kernel::dev::rdp::commands as rdp_commands;
-
-use n64_pac::vi;
+use kernel::dev::vi;
 
 /// Addresses of two 640x480 32-bit RGBA frame buffers
 ///
@@ -35,76 +34,89 @@ const FRAME_BUFFER_2_VADDR: usize = 0xA02D4000;  // ..0xA0400000
 
 static mut DISPLAY_LIST: [u64; 9] = [0; 9];
 
-/// Initializes the video interface (NTSC, 640x480, 32-bit color)
+/// Initializes the video interface (NTSC, 640x480 (480i), 32-bit color)
 ///
 /// Documentation:
 ///     - https://n64brew.dev/wiki/Video_Interface
 ///
 #[inline(never)]
 fn init_vi() {
+    let video_interface = vi::VI::new();
+    let mut video_control = vi::VI_CTRL(0)
+        .with_color_depth(vi::ColorDepth::Blank)  // stop the signal for setup
+        .with_aa_mode(vi::AntiAliasMode::Disabled)
+        .with_pixel_advance(0b0011)
+        .with_enable_serrate(true)
+        .with_enable_dither_filter(false)
+        .with_enable_divot(false)
+        .with_enable_gamma_boost(false)
+        .with_enable_gamma_dither(false);
     unsafe {
-        vi::set_origin(FRAME_BUFFER_1_VADDR as u32);
-        vi::set_ctrl(
-            vi::CtrlReg(0)
-                .with_dither_filter_enable(false)
-                .with_pixel_advance(0b0011)
-                .with_aa_mode(vi::AntiAliasMode::Disabled)
-                .with_serrate(false)
-                .with_divot_enable(false)
-                .with_gamma_enable(false)
-                .with_gamma_dither_enable(false)
-                .with_depth(vi::ColorDepth::BPP32)
+        video_interface.ctrl.write(video_control);
+        video_interface.origin.write(
+            vi::VI_ORIGIN(0)
+                .with_vaddr(FRAME_BUFFER_1_VADDR as u32)
         );
-        vi::set_width(640);
-        vi::set_v_intr(0x3FF);
-        vi::set_burst(
-            vi::BurstReg(0)
-                .with_burst_start(62)
-                .with_vsync_width(5)
-                .with_burst_width(34)
+        video_interface.width.write(
+            vi::VI_WIDTH(0)
+                .with_width(640)
+        );
+        video_interface.v_intr.write(
+            vi::VI_V_INTR(0)
+                .with_half_line(1000)
+        );
+        video_interface.burst.write(
+            vi::VI_BURST(0)
+                .with_color_burst_start(62)
+                .with_color_burst_width(34)
                 .with_hsync_width(57)
+                .with_vsync_width(5)
+        );
+        video_interface.v_sync.write(
+            vi::VI_V_SYNC(0)
+                .with_v_sync((524 * 2) - 1)
         );
-        vi::set_v_sync(0x20D);
-        vi::set_h_sync(
-            vi::HSyncReg(0)
-                .with_leap(0)
-                .with_h_sync(0xC15)
+        video_interface.h_sync.write(
+            vi::VI_H_SYNC(0)
+                .with_leap_pattern(0)
+                .with_line_duration(3093)
         );
-        vi::set_h_sync_leap(
-            vi::HSyncLeapReg(0)
-                .with_leap_a(0xC15)
-                .with_leap_b(0xC15)
+        video_interface.h_sync_leap.write(
+            vi::VI_H_SYNC_LEAP(0)
+                .with_leap_a(3093)
+                .with_leap_b(3093)
         );
-        vi::set_h_video(
-            vi::HVideoReg(0)
-                .with_h_start(0x06C)
-                .with_h_end(0x2EC)
+        video_interface.h_video.write(
+            vi::VI_H_VIDEO(0)
+                .with_h_start(108)
+                .with_h_end(748)
         );
-        vi::set_v_video(
-            vi::VVideoReg(0)
+        video_interface.v_video.write(
+            vi::VI_V_VIDEO(0)
                 .with_v_start(0x025)
                 .with_v_end(0x1FF)
         );
-        vi::set_v_burst(
-            vi::VBurstReg(0)
+        video_interface.v_burst.write(
+            vi::VI_V_BURST(0)
                 .with_v_burst_start(0x00E)
                 .with_v_burst_end(0x204)
         );
-        vi::set_x_scale(
-            vi::XScaleReg(0)
-                .with_x_offset(0)
-                .with_x_scale(0b010000000000)
+        video_interface.x_scale.write(
+            vi::VI_X_SCALE(0)
+                .with_offset(0)
+                .with_scale(0b_01_0000000000)  // 2.10 fixed-point
         );
-        vi::set_y_scale(
-            vi::YScaleReg(0)
-                .with_y_offset(0)
-                .with_y_scale(0b100000000000)
+        video_interface.y_scale.write(
+            vi::VI_Y_SCALE(0)
+                .with_offset(0)
+                .with_scale(0b_10_0000000000)  // 2.10 fixed-point
         );
-
+        video_control.set_color_depth(vi::ColorDepth::TrueColor);  // begin the signal after setup
+        video_interface.ctrl.write(video_control);
     }
 }
 
-/// Blank the frame buffers ("fb1" & "fb2")
+/// Blank the frame buffers ("fb1" & "fb2") and write a test pattern.
 ///
 #[inline(never)]
 fn init_fbs() {

kernel/src/dev/mod.rs

@@ -2,7 +2,8 @@
 
 //! Device interfaces and supporting structures
 
-pub mod reg;
 pub mod rdp;
+pub mod reg;
+pub mod vi;
 
 // eof