From 50b42eda0d785c290ecee2510af05177c4975a3f Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Wed, 2 Feb 2022 13:36:08 -0700
Subject: [PATCH] VBE mode info in Rust binary
---
src/lib.rs | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 101 insertions(+), 2 deletions(-)
diff --git a/src/lib.rs b/src/lib.rs
index f6d5347..5e298c0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -55,6 +55,61 @@ impl ThunkData {
}
}
+#[derive(Clone, Copy, Debug)]
+#[repr(packed)]
+pub struct VbeCardInfo {
+ signature: [u8; 4],
+ version: u16,
+ oemstring: u32,
+ capabilities: u32,
+ videomodeptr: u32,
+ totalmemory: u16,
+ oemsoftwarerev: u16,
+ oemvendornameptr: u32,
+ oemproductnameptr: u32,
+ oemproductrevptr: u32,
+ reserved: [u8; 222],
+ oemdata: [u8; 256],
+}
+
+#[derive(Clone, Copy, Debug)]
+#[repr(packed)]
+pub struct VbeModeInfo {
+ attributes: u16,
+ winA: u8,
+ winB: u8,
+ granularity: u16,
+ winsize: u16,
+ segmentA: u16,
+ segmentB: u16,
+ winfuncptr: u32,
+ bytesperscanline: u16,
+ xresolution: u16,
+ yresolution: u16,
+ xcharsize: u8,
+ ycharsize: u8,
+ numberofplanes: u8,
+ bitsperpixel: u8,
+ numberofbanks: u8,
+ memorymodel: u8,
+ banksize: u8,
+ numberofimagepages: u8,
+ unused: u8,
+ redmasksize: u8,
+ redfieldposition: u8,
+ greenmasksize: u8,
+ greenfieldposition: u8,
+ bluemasksize: u8,
+ bluefieldposition: u8,
+ rsvdmasksize: u8,
+ rsvdfieldposition: u8,
+ directcolormodeinfo: u8,
+ physbaseptr: u32,
+ offscreenmemoryoffset: u32,
+ offscreenmemsize: u16,
+ reserved: [u8; 206],
+}
+
#[derive(Clone, Copy)]
#[repr(packed)]
pub struct VgaTextBlock {
@@ -178,15 +233,59 @@ pub unsafe extern "C" fn kstart(
(VgaTextColor::White as u8);
}
- writeln!(vga, "Arrow keys and space select mode, enter to continue");
+ {
+ // Get card info
+ let mut data = ThunkData::new();
+ data.ax = 0x4F00;
+ data.di = 0x1000;
+ data.with(thunk10);
+ if data.ax == 0x004F {
+ let card_info = ptr::read(0x1000 as *const VbeCardInfo);
+ let mut modes = card_info.videomodeptr as *const u16;
+ loop {
+ let mode = *modes;
+ if mode == 0xFFFF {
+ break;
+ }
+ modes = modes.add(1);
+
+ // Get mode info
+ let mut data = ThunkData::new();
+ data.ax = 0x4F01;
+ // Ask for linear frame buffer with mode
+ data.cx = mode | (1 << 14);
+ data.di = 0x2000;
+ data.with(thunk10);
+ if data.ax == 0x004F {
+ let mode_info = ptr::read(0x2000 as *const VbeModeInfo);
+
+ // We only support 32-bits per pixel modes
+ if mode_info.bitsperpixel == 32 {
+ writeln!(
+ vga,
+ "{}x{}",
+ mode_info.xresolution,
+ mode_info.yresolution
+ );
+ }
+ } else {
+ writeln!(vga, "Failed to read VBE mode 0x{:04X} info: 0x{:04X}", mode, data.ax);
+ }
+ }
+ } else {
+ writeln!(vga, "Failed to read VBE card info: 0x{:04X}", data.ax);
+ }
+ }
+
+ writeln!(vga, "Arrow keys and space select mode, enter to continue");
loop {
// Read keypress
let mut data = ThunkData::new();
data.with(thunk16);
writeln!(
vga,
- "'{}' 0x{:02X}",
+ "{:?} 0x{:02X}",
(data.ax as u8) as char,
(data.ax >> 8) as u8
);
--
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