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Avoid accidental lockups

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This commit is contained in:
Ryan Kennedy 2020-03-29 17:18:54 -05:00
parent 2b781e647d
commit 689ecc7bf3
1 changed files with 11 additions and 14 deletions
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25
src/writers/mod.rs
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@ -8,9 +8,8 @@ mod text_80x25;
use super::{
colors::{Color16, TextModeColor},
registers::CrtcControllerIndex,
vga::{Vga, VGA},
vga::VGA,
};
use spinning_top::SpinlockGuard;
pub use graphics_320x200x256::Graphics320x200x256;
pub use graphics_640x480x16::Graphics640x480x16;
@ -64,20 +63,18 @@ pub trait TextWriter: Screen {
/// the `TextWriter` implementation.
fn set_mode(&self);
/// Returns the start of the `FrameBuffer` as `*mut ScreenCharacter`
/// as well as a lock to the vga driver. This ensures the vga
/// driver stays locked while the frame buffer is in use.
fn get_frame_buffer(&self) -> (SpinlockGuard<Vga>, *mut ScreenCharacter) {
/// Returns the start of the `FrameBuffer` as `*mut ScreenCharacter`.
fn get_frame_buffer(&self) -> *mut ScreenCharacter {
let mut vga = VGA.lock();
let frame_buffer = vga.get_frame_buffer();
(vga, u32::from(frame_buffer) as *mut ScreenCharacter)
u32::from(frame_buffer) as *mut ScreenCharacter
}
/// Clears the screen by setting all cells to `b' '` with
/// a background color of `Color16::Black` and a foreground
/// color of `Color16::Yellow`.
fn clear_screen(&self) {
let (_vga, frame_buffer) = self.get_frame_buffer();
let frame_buffer = self.get_frame_buffer();
let screen_size = self.get_width() * self.get_height();
for i in 0..screen_size {
unsafe {
@ -88,7 +85,7 @@ pub trait TextWriter: Screen {
/// Disables the cursor in vga text modes.
fn disable_cursor(&self) {
let (mut vga, _frame_buffer) = self.get_frame_buffer();
let mut vga = VGA.lock();
let emulation_mode = vga.get_emulation_mode();
let cursor_start = vga
.crtc_controller_registers
@ -102,7 +99,7 @@ pub trait TextWriter: Screen {
/// Enables the cursor in vga text modes.
fn enable_cursor(&self) {
let (mut vga, _frame_buffer) = self.get_frame_buffer();
let mut vga = VGA.lock();
let emulation_mode = vga.get_emulation_mode();
let cursor_start = vga
.crtc_controller_registers
@ -116,7 +113,7 @@ pub trait TextWriter: Screen {
/// Returns the `ScreenCharacter` at the given `(x, y)` position.
fn read_character(&self, x: usize, y: usize) -> ScreenCharacter {
let (_vga, frame_buffer) = self.get_frame_buffer();
let frame_buffer = self.get_frame_buffer();
let offset = self.get_width() * y + x;
unsafe { frame_buffer.add(offset).read_volatile() }
}
@ -128,7 +125,7 @@ pub trait TextWriter: Screen {
/// determined by `CrtcControllerIndex::MaxiumumScanLine (usually 15)`.
/// If `scan_line_start > scan_line_end`, the cursor isn't drawn.
fn set_cursor(&self, scan_line_start: u8, scan_line_end: u8) {
let (mut vga, _frame_buffer) = self.get_frame_buffer();
let mut vga = VGA.lock();
let emulation_mode = vga.get_emulation_mode();
let cursor_start = vga
.crtc_controller_registers
@ -154,7 +151,7 @@ pub trait TextWriter: Screen {
/// `x` and `y`.
fn set_cursor_position(&self, x: usize, y: usize) {
let offset = self.get_width() * y + x;
let (mut vga, _frame_buffer) = self.get_frame_buffer();
let mut vga = VGA.lock();
let emulation_mode = vga.get_emulation_mode();
let cursor_start = offset & 0xFF;
let cursor_end = (offset >> 8) & 0xFF;
@ -172,7 +169,7 @@ pub trait TextWriter: Screen {
/// Prints the given `character` and `color` at `(x, y)`.
fn write_character(&self, x: usize, y: usize, screen_character: ScreenCharacter) {
let (_vga, frame_buffer) = self.get_frame_buffer();
let frame_buffer = self.get_frame_buffer();
let offset = self.get_width() * y + x;
unsafe {
frame_buffer.add(offset).write_volatile(screen_character);