From 5313f46e61fc7c8bca3072e6d210e2dccbebfc72 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Wed, 2 Feb 2022 15:04:05 -0700
Subject: [PATCH] Put magic addresses in one place
---
src/lib.rs | 30 +++++++++++++-----------------
1 file changed, 13 insertions(+), 17 deletions(-)
diff --git a/src/lib.rs b/src/lib.rs
index ee25e9c..e9eb4e5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,6 +17,11 @@ use linked_list_allocator::LockedHeap;
mod panic;
+const VBE_CARD_INFO_ADDR: usize = 0x1000;
+const VBE_MODE_INFO_ADDR: usize = 0x2000;
+const STACK_ADDR: usize = 0x7C00;
+const VGA_ADDR: usize = 0xB8000;
+
#[global_allocator]
static ALLOCATOR: LockedHeap = LockedHeap::empty();
@@ -34,14 +39,12 @@ pub struct ThunkData {
}
impl ThunkData {
- pub const STACK: usize = 0x7C00;
-
pub fn new() -> Self {
Self {
di: 0,
si: 0,
bp: 0,
- sp: Self::STACK as u16,
+ sp: STACK_ADDR as u16,
bx: 0,
dx: 0,
cx: 0,
@@ -50,11 +53,11 @@ impl ThunkData {
}
pub unsafe fn save(&self) {
- ptr::write((Self::STACK - 16) as *mut ThunkData, *self);
+ ptr::write((STACK_ADDR - 16) as *mut ThunkData, *self);
}
pub unsafe fn load(&mut self) {
- *self = ptr::read((Self::STACK - 16) as *const ThunkData);
+ *self = ptr::read((STACK_ADDR - 16) as *const ThunkData);
}
pub unsafe fn with(&mut self, f: extern "C" fn()) {
@@ -241,7 +244,7 @@ pub unsafe extern "C" fn kstart(
data.with(thunk10);
}
- let mut vga = Vga::new(0xb8000 as *mut VgaTextBlock, 80, 25);
+ let mut vga = Vga::new(VGA_ADDR as *mut VgaTextBlock, 80, 25);
for i in 0..vga.blocks.len() {
vga.blocks[i].char = 0;
@@ -263,10 +266,10 @@ pub unsafe extern "C" fn kstart(
// Get card info
let mut data = ThunkData::new();
data.ax = 0x4F00;
- data.di = 0x1000;
+ data.di = VBE_CARD_INFO_ADDR as u16;
data.with(thunk10);
if data.ax == 0x004F {
- let card_info = ptr::read(0x1000 as *const VbeCardInfo);
+ let card_info = ptr::read(VBE_CARD_INFO_ADDR as *const VbeCardInfo);
let mut mode_ptr = card_info.videomodeptr as *const u16;
loop {
@@ -281,10 +284,10 @@ pub unsafe extern "C" fn kstart(
let mut data = ThunkData::new();
data.ax = 0x4F01;
data.cx = mode;
- data.di = 0x2000;
+ data.di = VBE_MODE_INFO_ADDR as u16;
data.with(thunk10);
if data.ax == 0x004F {
- let mode_info = ptr::read(0x2000 as *const VbeModeInfo);
+ let mode_info = ptr::read(VBE_MODE_INFO_ADDR as *const VbeModeInfo);
// We only support 32-bits per pixel modes
if mode_info.bitsperpixel != 32 {
@@ -354,13 +357,6 @@ pub unsafe extern "C" fn kstart(
// Read keypress
let mut data = ThunkData::new();
data.with(thunk16);
- writeln!(
- vga,
- "{:?} 0x{:02X}",
- (data.ax as u8) as char,
- (data.ax >> 8) as u8
- );
-
match (data.ax >> 8) as u8 {
0x4B /* Left */ => {
if let Some(mut mode_i) = modes.iter().position(|x| x.0 == selected) {
--
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