io register groundwork

the current goal is to get enough done that we can write a sensical looking hello world game, and then put a writeup of that into the book.
2024-12-23 19:01:30 +11:00 · 2018-11-07 23:43:22 -07:00 · 2018-11-07 23:43:22 -07:00 · e9b26f838b
parent c99a85bf39
commit e9b26f838b
4 changed files with 409 additions and 0 deletions
--- a/src/core_extras.rs
+++ b/src/core_extras.rs
@ -0,0 +1,40 @@
+//! Things that I wish were in core, but aren't.
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[repr(transparent)]
+/// A simple wrapper to any `*mut T` so that the basic "read" and "write"
+/// operations are volatile.
+///
+/// Accessing the GBA's IO registers and video ram and specific other places on
+/// **must** be done with volatile operations. Having this wrapper makes that
+/// more clear for all the global const values into IO registers.
+pub struct VolatilePtr<T>(pub *mut T);
+
+impl<T> core::fmt::Pointer for VolatilePtr<T> {
+  /// Formats exactly like the inner `*mut T`.
+  fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+    write!(f, "{:p}", self.0)
+  }
+}
+
+impl<T> VolatilePtr<T> {
+  /// Performs a volatile read.
+  ///
+  /// # Safety
+  ///
+  /// This method adds absolutely no additional safety, so all safety concerns
+  /// for a normal raw pointer volatile read apply.
+  pub unsafe fn read(&self) -> T {
+    core::ptr::read_volatile(self.0)
+  }
+
+  /// Performs a volatile write.
+  ///
+  /// # Safety
+  ///
+  /// This method adds absolutely no additional safety, so all safety concerns
+  /// for a normal raw pointer volatile write apply.
+  pub unsafe fn write(&self, data: T) {
+    core::ptr::write_volatile(self.0, data);
+  }
+}
--- a/src/io_registers.rs
+++ b/src/io_registers.rs
@ -0,0 +1,341 @@
+//! The module for all things relating to the IO Register portion of the GBA's
+//! memory map.
+//!
+//! Here we define many constants for the volatile pointers to the various IO
+//! registers. Each raw register constant is named according to the name given
+//! to it in GBATEK's [GBA I/O
+//! Map](http://problemkaputt.de/gbatek.htm#gbaiomap). They program in C, and so
+//! of course all the names terrible and missing as many vowels as possible.
+//! However, being able to look it up online is the most important thing here,
+//! so oh well.
+//!
+//! In addition to the const `VolatilePtr` values, we will over time be adding
+//! safe wrappers around each register, including newtypes and such so that you
+//! can easily work with whatever each specific register is doing.
+
+// TODO(lokathor): IO Register newtypes.
+
+use super::*;
+
+/// LCD Control. Read/Write.
+///
+/// * [gbatek entry](http://problemkaputt.de/gbatek.htm#lcdiodisplaycontrol)
+pub const DISPCNT: VolatilePtr<u16> = VolatilePtr(0x4000000 as *mut u16);
+
+/// Undocumented - Green Swap
+pub const GREEN_SWAP: VolatilePtr<u16> = VolatilePtr(0x4000002 as *mut u16);
+
+/// General LCD Status (STAT,LYC)
+pub const DISPSTAT: VolatilePtr<u16> = VolatilePtr(0x4000004 as *mut u16);
+
+/// Vertical Counter (LY)
+pub const VCOUNT: VolatilePtr<u16> = VolatilePtr(0x4000006 as *mut u16);
+
+/// BG0 Control
+pub const BG0CNT: VolatilePtr<u16> = VolatilePtr(0x4000008 as *mut u16);
+
+/// BG1 Control
+pub const BG1CNT: VolatilePtr<u16> = VolatilePtr(0x400000A as *mut u16);
+
+/// BG2 Control
+pub const BG2CNT: VolatilePtr<u16> = VolatilePtr(0x400000C as *mut u16);
+
+/// BG3 Control
+pub const BG3CNT: VolatilePtr<u16> = VolatilePtr(0x400000E as *mut u16);
+
+/// BG0 X-Offset
+pub const BG0HOFS: VolatilePtr<u16> = VolatilePtr(0x4000010 as *mut u16);
+
+/// BG0 Y-Offset
+pub const BG0VOFS: VolatilePtr<u16> = VolatilePtr(0x4000012 as *mut u16);
+
+/// BG1 X-Offset
+pub const BG1HOFS: VolatilePtr<u16> = VolatilePtr(0x4000014 as *mut u16);
+
+/// BG1 Y-Offset
+pub const BG1VOFS: VolatilePtr<u16> = VolatilePtr(0x4000016 as *mut u16);
+
+/// BG2 X-Offset
+pub const BG2HOFS: VolatilePtr<u16> = VolatilePtr(0x4000018 as *mut u16);
+
+/// BG2 Y-Offset
+pub const BG2VOFS: VolatilePtr<u16> = VolatilePtr(0x400001A as *mut u16);
+
+/// BG3 X-Offset
+pub const BG3HOFS: VolatilePtr<u16> = VolatilePtr(0x400001C as *mut u16);
+
+/// BG3 Y-Offset
+pub const BG3VOFS: VolatilePtr<u16> = VolatilePtr(0x400001E as *mut u16);
+
+/// BG2 Rotation/Scaling Parameter A (dx)
+pub const BG2PA: VolatilePtr<u16> = VolatilePtr(0x4000020 as *mut u16);
+
+/// BG2 Rotation/Scaling Parameter B (dmx)
+pub const BG2PB: VolatilePtr<u16> = VolatilePtr(0x4000022 as *mut u16);
+
+/// BG2 Rotation/Scaling Parameter C (dy)
+pub const BG2PC: VolatilePtr<u16> = VolatilePtr(0x4000024 as *mut u16);
+
+/// BG2 Rotation/Scaling Parameter D (dmy)
+pub const BG2PD: VolatilePtr<u16> = VolatilePtr(0x4000026 as *mut u16);
+
+/// BG2 Reference Point X-Coordinate
+pub const BG2X: VolatilePtr<u32> = VolatilePtr(0x4000028 as *mut u32);
+
+/// BG2 Reference Point Y-Coordinate
+pub const BG2Y: VolatilePtr<u32> = VolatilePtr(0x400002C as *mut u32);
+
+/// BG3 Rotation/Scaling Parameter A (dx)
+pub const BG3PA: VolatilePtr<u16> = VolatilePtr(0x4000030 as *mut u16);
+
+/// BG3 Rotation/Scaling Parameter B (dmx)
+pub const BG3PB: VolatilePtr<u16> = VolatilePtr(0x4000032 as *mut u16);
+
+/// BG3 Rotation/Scaling Parameter C (dy)
+pub const BG3PC: VolatilePtr<u16> = VolatilePtr(0x4000034 as *mut u16);
+
+/// BG3 Rotation/Scaling Parameter D (dmy)
+pub const BG3PD: VolatilePtr<u16> = VolatilePtr(0x4000036 as *mut u16);
+
+/// BG3 Reference Point X-Coordinate
+pub const BG3X: VolatilePtr<u32> = VolatilePtr(0x4000038 as *mut u32);
+
+/// BG3 Reference Point Y-Coordinate
+pub const BG3Y: VolatilePtr<u32> = VolatilePtr(0x400003C as *mut u32);
+
+/// Window 0 Horizontal Dimensions
+pub const WIN0H: VolatilePtr<u16> = VolatilePtr(0x4000040 as *mut u16);
+
+/// Window 1 Horizontal Dimensions
+pub const WIN1H: VolatilePtr<u16> = VolatilePtr(0x4000042 as *mut u16);
+
+/// Window 0 Vertical Dimensions
+pub const WIN0V: VolatilePtr<u16> = VolatilePtr(0x4000044 as *mut u16);
+
+/// Window 1 Vertical Dimensions
+pub const WIN1V: VolatilePtr<u16> = VolatilePtr(0x4000046 as *mut u16);
+
+/// Inside of Window 0 and 1
+pub const WININ: VolatilePtr<u16> = VolatilePtr(0x4000048 as *mut u16);
+
+/// Inside of OBJ Window & Outside of Windows
+pub const WINOUT: VolatilePtr<u16> = VolatilePtr(0x400004A as *mut u16);
+
+/// Mosaic Size
+pub const MOSAIC: VolatilePtr<u16> = VolatilePtr(0x400004C as *mut u16);
+
+/// Color Special Effects Selection
+pub const BLDCNT: VolatilePtr<u16> = VolatilePtr(0x4000050 as *mut u16);
+
+/// Alpha Blending Coefficients
+pub const BLDALPHA: VolatilePtr<u16> = VolatilePtr(0x4000052 as *mut u16);
+
+/// Brightness (Fade-In/Out) Coefficient
+pub const BLDY: VolatilePtr<u16> = VolatilePtr(0x4000054 as *mut u16);
+
+/// Channel 1 Sweep register       (NR10)
+pub const UND1CNT_L: VolatilePtr<u16> = VolatilePtr(0x4000060 as *mut u16);
+
+/// Channel 1 Duty/Length/Envelope (NR11, NR12)
+pub const UND1CNT_H: VolatilePtr<u16> = VolatilePtr(0x4000062 as *mut u16);
+
+/// Channel 1 Frequency/Control    (NR13, NR14)
+pub const UND1CNT_X: VolatilePtr<u16> = VolatilePtr(0x4000064 as *mut u16);
+
+/// Channel 2 Duty/Length/Envelope (NR21, NR22)
+pub const UND2CNT_L: VolatilePtr<u16> = VolatilePtr(0x4000068 as *mut u16);
+
+/// Channel 2 Frequency/Control    (NR23, NR24)
+pub const UND2CNT_H: VolatilePtr<u16> = VolatilePtr(0x400006C as *mut u16);
+
+/// Channel 3 Stop/Wave RAM select (NR30)
+pub const UND3CNT_L: VolatilePtr<u16> = VolatilePtr(0x4000070 as *mut u16);
+
+/// Channel 3 Length/Volume        (NR31, NR32)
+pub const UND3CNT_H: VolatilePtr<u16> = VolatilePtr(0x4000072 as *mut u16);
+
+/// Channel 3 Frequency/Control    (NR33, NR34)
+pub const UND3CNT_X: VolatilePtr<u16> = VolatilePtr(0x4000074 as *mut u16);
+
+/// Channel 4 Length/Envelope      (NR41, NR42)
+pub const UND4CNT_L: VolatilePtr<u16> = VolatilePtr(0x4000078 as *mut u16);
+
+/// Channel 4 Frequency/Control    (NR43, NR44)
+pub const UND4CNT_H: VolatilePtr<u16> = VolatilePtr(0x400007C as *mut u16);
+
+/// Control Stereo/Volume/Enable   (NR50, NR51)
+pub const UNDCNT_L: VolatilePtr<u16> = VolatilePtr(0x4000080 as *mut u16);
+
+/// Control Mixing/DMA Control
+pub const UNDCNT_H: VolatilePtr<u16> = VolatilePtr(0x4000082 as *mut u16);
+
+/// Control Sound on/off           (NR52)
+pub const UNDCNT_X: VolatilePtr<u16> = VolatilePtr(0x4000084 as *mut u16);
+
+/// Sound PWM Control
+pub const UNDBIAS: VolatilePtr<u16> = VolatilePtr(0x4000088 as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM0_L: VolatilePtr<u16> = VolatilePtr(0x4000090 as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM0_H: VolatilePtr<u16> = VolatilePtr(0x4000092 as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM1_L: VolatilePtr<u16> = VolatilePtr(0x4000094 as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM1_H: VolatilePtr<u16> = VolatilePtr(0x4000096 as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM2_L: VolatilePtr<u16> = VolatilePtr(0x4000098 as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM2_H: VolatilePtr<u16> = VolatilePtr(0x400009A as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM3_L: VolatilePtr<u16> = VolatilePtr(0x400009C as *mut u16);
+
+/// Channel 3 Wave Pattern RAM (W/R)
+pub const WAVE_RAM3_H: VolatilePtr<u16> = VolatilePtr(0x400009E as *mut u16);
+
+/// Channel A FIFO, Data 0-3
+pub const FIFO_A: VolatilePtr<u32> = VolatilePtr(0x40000A0 as *mut u32);
+
+/// Channel B FIFO, Data 0-3
+pub const FIFO_B: VolatilePtr<u32> = VolatilePtr(0x40000A4 as *mut u32);
+
+/// DMA 0 Source Address
+pub const DMA0SAD: VolatilePtr<u32> = VolatilePtr(0x40000B0 as *mut u32);
+
+/// DMA 0 Destination Address
+pub const DMA0DAD: VolatilePtr<u32> = VolatilePtr(0x40000B4 as *mut u32);
+
+/// DMA 0 Word Count
+pub const DMA0CNT_L: VolatilePtr<u16> = VolatilePtr(0x40000B8 as *mut u16);
+
+/// DMA 0 Control
+pub const DMA0CNT_H: VolatilePtr<u16> = VolatilePtr(0x40000BA as *mut u16);
+
+/// DMA 1 Source Address
+pub const DMA1SAD: VolatilePtr<u32> = VolatilePtr(0x40000BC as *mut u32);
+
+/// DMA 1 Destination Address
+pub const DMA1DAD: VolatilePtr<u32> = VolatilePtr(0x40000C0 as *mut u32);
+
+/// DMA 1 Word Count
+pub const DMA1CNT_L: VolatilePtr<u16> = VolatilePtr(0x40000C4 as *mut u16);
+
+/// DMA 1 Control
+pub const DMA1CNT_H: VolatilePtr<u16> = VolatilePtr(0x40000C6 as *mut u16);
+
+/// DMA 2 Source Address
+pub const DMA2SAD: VolatilePtr<u32> = VolatilePtr(0x40000C8 as *mut u32);
+
+/// DMA 2 Destination Address
+pub const DMA2DAD: VolatilePtr<u32> = VolatilePtr(0x40000CC as *mut u32);
+
+/// DMA 2 Word Count
+pub const DMA2CNT_L: VolatilePtr<u16> = VolatilePtr(0x40000D0 as *mut u16);
+
+/// DMA 2 Control
+pub const DMA2CNT_H: VolatilePtr<u16> = VolatilePtr(0x40000D2 as *mut u16);
+
+/// DMA 3 Source Address
+pub const DMA3SAD: VolatilePtr<u32> = VolatilePtr(0x40000D4 as *mut u32);
+
+/// DMA 3 Destination Address
+pub const DMA3DAD: VolatilePtr<u32> = VolatilePtr(0x40000D8 as *mut u32);
+
+/// DMA 3 Word Count
+pub const DMA3CNT_L: VolatilePtr<u16> = VolatilePtr(0x40000DC as *mut u16);
+
+/// DMA 3 Control
+pub const DMA3CNT_H: VolatilePtr<u16> = VolatilePtr(0x40000DE as *mut u16);
+
+/// Timer 0 Counter/Reload
+pub const TM0CNT_L: VolatilePtr<u16> = VolatilePtr(0x4000100 as *mut u16);
+
+/// Timer 0 Control
+pub const TM0CNT_H: VolatilePtr<u16> = VolatilePtr(0x4000102 as *mut u16);
+
+/// Timer 1 Counter/Reload
+pub const TM1CNT_L: VolatilePtr<u16> = VolatilePtr(0x4000104 as *mut u16);
+
+/// Timer 1 Control
+pub const TM1CNT_H: VolatilePtr<u16> = VolatilePtr(0x4000106 as *mut u16);
+
+/// Timer 2 Counter/Reload
+pub const TM2CNT_L: VolatilePtr<u16> = VolatilePtr(0x4000108 as *mut u16);
+
+/// Timer 2 Control
+pub const TM2CNT_H: VolatilePtr<u16> = VolatilePtr(0x400010A as *mut u16);
+
+/// Timer 3 Counter/Reload
+pub const TM3CNT_L: VolatilePtr<u16> = VolatilePtr(0x400010C as *mut u16);
+
+/// Timer 3 Control
+pub const TM3CNT_H: VolatilePtr<u16> = VolatilePtr(0x400010E as *mut u16);
+
+/// SIO Data (Normal-32bit Mode; shared with below)
+pub const SIODATA32: VolatilePtr<u32> = VolatilePtr(0x4000120 as *mut u32);
+
+/// SIO Data 0 (Parent)    (Multi-Player Mode)
+pub const SIOMULTI0: VolatilePtr<u16> = VolatilePtr(0x4000120 as *mut u16);
+
+/// SIO Data 1 (1st Child) (Multi-Player Mode)
+pub const SIOMULTI1: VolatilePtr<u16> = VolatilePtr(0x4000122 as *mut u16);
+
+/// SIO Data 2 (2nd Child) (Multi-Player Mode)
+pub const SIOMULTI2: VolatilePtr<u16> = VolatilePtr(0x4000124 as *mut u16);
+
+/// SIO Data 3 (3rd Child) (Multi-Player Mode)
+pub const SIOMULTI3: VolatilePtr<u16> = VolatilePtr(0x4000126 as *mut u16);
+
+/// SIO Control Register
+pub const SIOCNT: VolatilePtr<u16> = VolatilePtr(0x4000128 as *mut u16);
+
+/// D SIO Data (Local of MultiPlayer; shared below)
+pub const SIOMLT_SEN: VolatilePtr<u16> = VolatilePtr(0x400012A as *mut u16);
+
+/// SIO Data (Normal-8bit and UART Mode)
+pub const SIODATA8: VolatilePtr<u16> = VolatilePtr(0x400012A as *mut u16);
+
+/// Key Status
+pub const KEYINPUT: VolatilePtr<u16> = VolatilePtr(0x4000130 as *mut u16);
+
+/// Key Interrupt Control
+pub const KEYCNT: VolatilePtr<u16> = VolatilePtr(0x4000132 as *mut u16);
+
+/// SIO Mode Select/General Purpose Data
+pub const RCNT: VolatilePtr<u16> = VolatilePtr(0x4000134 as *mut u16);
+
+/// SIO JOY Bus Control
+pub const JOYCNT: VolatilePtr<u16> = VolatilePtr(0x4000140 as *mut u16);
+
+/// SIO JOY Bus Receive Data
+pub const JOY_RECV: VolatilePtr<u32> = VolatilePtr(0x4000150 as *mut u32);
+
+/// SIO JOY Bus Transmit Data
+pub const JOY_TRANS: VolatilePtr<u32> = VolatilePtr(0x4000154 as *mut u32);
+
+/// SIO JOY Bus Receive Status
+pub const JOYSTAT: VolatilePtr<u16> = VolatilePtr(0x4000158 as *mut u16);
+
+/// Interrupt Enable Register
+pub const IE: VolatilePtr<u16> = VolatilePtr(0x4000200 as *mut u16);
+
+/// Interrupt Request Flags / IRQ Acknowledge
+pub const IF: VolatilePtr<u16> = VolatilePtr(0x4000202 as *mut u16);
+
+/// Game Pak Waitstate Control
+pub const WAITCNT: VolatilePtr<u16> = VolatilePtr(0x4000204 as *mut u16);
+
+/// Interrupt Master Enable Register
+pub const IME: VolatilePtr<u16> = VolatilePtr(0x4000208 as *mut u16);
+
+/// Undocumented - Post Boot Flag
+pub const POSTFLG: VolatilePtr<u8> = VolatilePtr(0x4000300 as *mut u8);
+
+/// Undocumented - Power Down Control
+pub const HALTCNT: VolatilePtr<u8> = VolatilePtr(0x4000301 as *mut u8);
--- a/src/lib.rs
+++ b/src/lib.rs
@ -1 +1,23 @@
 #![no_std]
+#![warn(missing_docs)]
+
+//! This crate helps you write GBA ROMs.
+//!
+//! # SAFETY POLICY
+//!
+//! Some parts of this crate are safe wrappers around unsafe operations. This is
+//! good, and what you'd expect from a Rust crate.
+//!
+//! However, the safe wrappers all assume that you will _only_ attempt to
+//! execute this crate on a GBA or in a GBA Emulator.
+//!
+//! **Do not** use this crate in programs that aren't running on the GBA. If you
+//! do, it's a giant bag of Undefined Behavior.
+
+//pub mod macros; // un-comment once we get some
+
+pub mod core_extras;
+pub(crate) use crate::core_extras::*;
+
+pub mod io_registers;
+//pub(crate) use crate::io_registers::*;
--- a/src/macros.rs
+++ b/src/macros.rs
@ -0,0 +1,6 @@
+//! Module for all macros.
+//!
+//! Macros are the only thing in rust where declaration order matters, so we
+//! place all of them here regardless of what they do.
+
+// no macros yet!