From 1b16980ed7212c76b62b10a579f0abf730f85604 Mon Sep 17 00:00:00 2001
From: D4VID <d4vid@d4vid.xyz>
Date: Mon, 19 May 2025 22:32:33 +0200
Subject: [PATCH] Make a library

---
 lwcpu/.gitignore |  1 +
 lwcpu/Cargo.lock |  7 +++++
 lwcpu/Cargo.toml |  6 +++++
 lwcpu/src/lib.rs | 70 ++++++++++++++++++++++++++++++++++++++++++++++++
 test/Cargo.lock  |  5 ++++
 test/Cargo.toml  |  1 +
 test/src/main.rs | 26 +++++-------------
 7 files changed, 96 insertions(+), 20 deletions(-)
 create mode 100644 lwcpu/.gitignore
 create mode 100644 lwcpu/Cargo.lock
 create mode 100644 lwcpu/Cargo.toml
 create mode 100644 lwcpu/src/lib.rs

diff --git a/lwcpu/.gitignore b/lwcpu/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/lwcpu/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/lwcpu/Cargo.lock b/lwcpu/Cargo.lock
new file mode 100644
index 0000000..3da8965
--- /dev/null
+++ b/lwcpu/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "lwcpu"
+version = "0.1.0"
diff --git a/lwcpu/Cargo.toml b/lwcpu/Cargo.toml
new file mode 100644
index 0000000..ff3d212
--- /dev/null
+++ b/lwcpu/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "lwcpu"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/lwcpu/src/lib.rs b/lwcpu/src/lib.rs
new file mode 100644
index 0000000..7d2c9f4
--- /dev/null
+++ b/lwcpu/src/lib.rs
@@ -0,0 +1,70 @@
+#![no_std]
+
+use core::ptr::{read_volatile, write_volatile};
+
+const BASE_POINTER: u32 = 0x2000_0000;
+
+const NUMBER_DISPLAY_OFFSET : u32 = 0x00;
+const RANDOM_NUMBER_OFFSET  : u32 = 0x04;
+const BUTTONS_OFFSET        : u32 = 0x08;
+const TEXT_DISPLAY_OFFSET   : u32 = 0x0C;
+const KEYBOARD_OFFSET       : u32 = 0x10;
+const SCREEN_OFFSET         : u32 = 0x80;
+
+const NUMBER_DISPLAY_POINTER : *mut u32 = (BASE_POINTER + NUMBER_DISPLAY_OFFSET) as *mut u32;
+const RANDOM_NUMBER_POINTER  : *mut u32 = (BASE_POINTER + RANDOM_NUMBER_OFFSET)  as *mut u32;
+const BUTTONS_POINTER        : *mut u8  = (BASE_POINTER + BUTTONS_OFFSET)        as *mut u8;
+const TEXT_DISPLAY_POINTER   : *mut u8  = (BASE_POINTER + TEXT_DISPLAY_OFFSET)   as *mut u8;
+const KEYBOARD_POINTER       : *mut u32 = (BASE_POINTER + KEYBOARD_OFFSET)       as *mut u32;
+const SCREEN_POINTER         : *mut u32 = (BASE_POINTER + SCREEN_OFFSET)         as *mut u32;
+
+
+pub struct Screen {}
+impl Screen {
+    #[inline]
+    pub fn clear() {
+    }
+    #[inline]
+    pub fn turn_pixel_on(x: u8, y: u8) {
+        unsafe {
+            let mut row = read_volatile(SCREEN_POINTER.offset(y as isize));
+            row |= 1 << x;
+            write_volatile(SCREEN_POINTER.offset(y as isize), row);
+        }
+    }
+    #[inline]
+    pub fn turn_pixel_off(x: u8, y: u8) {
+        unsafe {
+            let mut row = read_volatile(SCREEN_POINTER.offset(y as isize));
+            row &= !(1 << x);
+            write_volatile(SCREEN_POINTER.offset(y as isize), row);
+        }
+    }
+    #[inline]
+    pub fn set_line(y: u8, value: u32) {
+        unsafe {
+            write_volatile(SCREEN_POINTER.offset(y as isize), value);
+        }
+    }
+}
+
+pub struct TextDisplay {}
+impl TextDisplay {
+    #[inline]
+    pub fn put_char(ch: u8) {
+        unsafe {
+            write_volatile(TEXT_DISPLAY_POINTER, ch);
+        }
+    }
+}
+
+pub struct NumberDisplay {}
+impl NumberDisplay {
+    #[inline]
+    pub fn display_number(number: u32) {
+        unsafe {
+            write_volatile(NUMBER_DISPLAY_POINTER, number);
+        }
+    }
+}
+
diff --git a/test/Cargo.lock b/test/Cargo.lock
index ff3ed61..3ec0c97 100644
--- a/test/Cargo.lock
+++ b/test/Cargo.lock
@@ -14,6 +14,10 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "361a90feb7004eca4019fb28352a9465666b24f840f5c3cddf0ff13920590b89"
 
+[[package]]
+name = "lwcpu"
+version = "0.1.0"
+
 [[package]]
 name = "paste"
 version = "1.0.15"
@@ -105,6 +109,7 @@ dependencies = [
 name = "test"
 version = "0.1.0"
 dependencies = [
+ "lwcpu",
  "riscv",
  "riscv-rt",
 ]
diff --git a/test/Cargo.toml b/test/Cargo.toml
index 805e70a..f5a403b 100644
--- a/test/Cargo.toml
+++ b/test/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 riscv = "0.12.1"
 riscv-rt = "0.13.0"
+lwcpu = { path = "../lwcpu" }
 
 # https://docs.rust-embedded.org/book/unsorted/speed-vs-size.html
 [profile.release]
diff --git a/test/src/main.rs b/test/src/main.rs
index b8f8e44..c5e2dbf 100644
--- a/test/src/main.rs
+++ b/test/src/main.rs
@@ -2,39 +2,25 @@
 #![no_main]
 
 use core::panic::PanicInfo;
+use lwcpu::{self, NumberDisplay, Screen, TextDisplay};
 use riscv_rt::entry;
 
 #[panic_handler]
 fn panic_handler(_info: &PanicInfo) -> ! {
-    unsafe {
-        OUTPUT.write_volatile(0xDEADC0DE);
-    }
+    NumberDisplay::display_number(0xDEADC0DE);
     loop {}
 }
 
-const OUTPUT: *mut u32 = 0x2000_0000 as *mut u32;
-const BTNS: *mut u8 = 0x2000_0008 as *mut u8;
-const TEXT: *mut u32 = 0x2000_000C as *mut u32;
-const SCREEN: *mut u32 = 0x2000_0080 as *mut u32;
-
 const HELLO_WORLD: &[u8; 13] = b" Hello world!";
 
 #[entry]
 fn main() -> ! {
-    unsafe {
-        SCREEN.write_volatile(0b101);
-    }
     for i in 0..31 {
-        unsafe {
-            let mut x = SCREEN.offset(i).read_volatile();
-            x <<= 1;
-            SCREEN.offset(i + 1).write_volatile(x);
-        }
+        Screen::set_line(i, 1 << i);
     }
-    for ch in HELLO_WORLD {
-        unsafe {
-            TEXT.write_volatile(*ch as u32);
+    loop {
+        for ch in HELLO_WORLD {
+            TextDisplay::put_char(*ch);
         }
     }
-    loop {}
 }