1#![no_std]
2
3pub const FB_WIDTH: usize = 320;
4pub const FB_HEIGHT: usize = 224;
5pub const FB_PIXELS: usize = FB_WIDTH * FB_HEIGHT;
6
7pub const AUDIO_SAMPLE_RATE: usize = 48_000;
8pub const AUDIO_CHANNELS: usize = 2;
9pub const AUDIO_FRAMES_PER_VIDEO_FRAME: usize = 800;
10pub const AUDIO_SAMPLES: usize = AUDIO_FRAMES_PER_VIDEO_FRAME * AUDIO_CHANNELS;
11
12pub const CONTROLLER_BUTTONS: usize = 12;
13
14const SYS_GET_FRAMEBUFFER: usize = 500;
15const SYS_GET_AUDIOBUFFER: usize = 501;
16const SYS_CONTROLLER_1: usize = 502;
17const SYS_CONTROLLER_2: usize = 503;
18const SYS_CONTROLLER_3: usize = 504;
19const SYS_CONTROLLER_4: usize = 505;
20const SYS_PRESENT: usize = 506;
21
22#[repr(u8)]
23#[derive(Copy, Clone)]
24pub enum Button {
25 Up = 0,
26 Down = 1,
27 Left = 2,
28 Right = 3,
29 A = 4,
30 B = 5,
31 X = 6,
32 Y = 7,
33 L1 = 8,
34 R1 = 9,
35 Start = 10,
36 Select = 11,
37}
38
39#[inline]
40fn syscall0(sysno: usize) -> usize {
41 #[cfg(target_arch = "riscv32")]
42 {
43 let mut a0: usize;
44 unsafe {
45 core::arch::asm!(
46 "ecall",
47 in("a7") sysno,
48 lateout("a0") a0,
49 options(nostack)
50 );
51 }
52 a0
53 }
54
55 #[cfg(not(target_arch = "riscv32"))]
56 {
57 let _ = sysno;
58 0
59 }
60}
61
62#[inline]
63pub fn framebuffer() -> *mut u32 {
64 syscall0(SYS_GET_FRAMEBUFFER) as *mut u32
65}
66
67#[inline]
68pub fn audiobuffer() -> *mut i16 {
69 syscall0(SYS_GET_AUDIOBUFFER) as *mut i16
70}
71
72#[inline]
73pub fn controller_1() -> *const u8 {
74 syscall0(SYS_CONTROLLER_1) as *const u8
75}
76
77#[inline]
78pub fn controller_2() -> *const u8 {
79 syscall0(SYS_CONTROLLER_2) as *const u8
80}
81
82#[inline]
83pub fn controller_3() -> *const u8 {
84 syscall0(SYS_CONTROLLER_3) as *const u8
85}
86
87#[inline]
88pub fn controller_4() -> *const u8 {
89 syscall0(SYS_CONTROLLER_4) as *const u8
90}
91
92#[inline]
93pub fn present() {
94 let _ = syscall0(SYS_PRESENT);
95}
96
97#[inline]
98pub fn rgb(r: u8, g: u8, b: u8) -> u32 {
99 ((r as u32) << 16) | ((g as u32) << 8) | (b as u32)
100}
101
102#[inline]
103pub fn button_level(packed: *const u8, button: Button) -> u8 {
104 let bit = (button as usize) * 2;
105 let byte_index = bit >> 3;
106 let shift = bit & 7;
107
108 unsafe { ((*packed.add(byte_index) >> shift) & 0x3) as u8 }
109}