From 234fb64999f6beacc2102ffc72f8fd8438f24481 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Wed, 24 Aug 2016 20:10:55 -0600
Subject: [PATCH] Add display

---
 Makefile                   |  3 +-
 arch/x86_64/src/display.rs | 91 ++++++++++++++++++++++++++++++++++++++
 arch/x86_64/src/lib.rs     |  3 ++
 arch/x86_64/src/start.rs   |  4 ++
 4 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 arch/x86_64/src/display.rs

diff --git a/Makefile b/Makefile
index e01020b..0e0057c 100644
--- a/Makefile
+++ b/Makefile
@@ -11,9 +11,10 @@ ifeq ($(UNAME),Darwin)
 endif
 
 QEMUFLAGS+=-smp 4 -machine q35
-QEMUFLAGS+=-serial mon:stdio -nographic
+QEMUFLAGS+=-serial mon:stdio
 QEMUFLAGS+=-d guest_errors
 #,int,pcall
+#-nographic
 #-device intel-iommu
 
 
diff --git a/arch/x86_64/src/display.rs b/arch/x86_64/src/display.rs
new file mode 100644
index 0000000..cb6acf8
--- /dev/null
+++ b/arch/x86_64/src/display.rs
@@ -0,0 +1,91 @@
+use core::slice;
+use spin::Mutex;
+
+use externs::memset;
+use memory::Frame;
+use paging::{ActivePageTable, PhysicalAddress, entry};
+
+/// The info of the VBE mode
+#[derive(Copy, Clone, Default, Debug)]
+#[repr(packed)]
+pub struct VBEModeInfo {
+    attributes: u16,
+    win_a: u8,
+    win_b: u8,
+    granularity: u16,
+    winsize: u16,
+    segment_a: u16,
+    segment_b: u16,
+    winfuncptr: u32,
+    bytesperscanline: u16,
+    pub xresolution: u16,
+    pub 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,
+}
+
+pub static DISPLAY: Mutex<Option<Display>> = Mutex::new(None);
+
+pub unsafe fn init(active_table: &mut ActivePageTable) {
+    active_table.identity_map(Frame::containing_address(PhysicalAddress::new(0x5200)), entry::PRESENT | entry::NO_EXECUTE);
+
+    let mode_info = &*(0x5200 as *const VBEModeInfo);
+    if mode_info.physbaseptr > 0 {
+        let width = mode_info.xresolution as usize;
+        let height = mode_info.yresolution as usize;
+        let start = mode_info.physbaseptr as usize;
+        let size = width * height;
+
+        {
+            let start_frame = Frame::containing_address(PhysicalAddress::new(start));
+            let end_frame = Frame::containing_address(PhysicalAddress::new(start + size * 4 - 1));
+            for frame in Frame::range_inclusive(start_frame, end_frame) {
+                active_table.identity_map(frame, entry::PRESENT | entry::WRITABLE | entry::NO_EXECUTE);
+            }
+        }
+
+        for i in 0..size {
+            let c = ((i * 256)/size) as u32 & 0xFF;
+            *(start as *mut u32).offset(i as isize) = (c << 16) | (c << 8) | c;
+        }
+        //memset(start as *mut u8, 0, size * 4);
+
+        *DISPLAY.lock() = Some(Display::new(width, height, slice::from_raw_parts_mut(start as *mut u32, size)));
+    }
+}
+
+/// A display
+pub struct Display {
+    pub width: usize,
+    pub height: usize,
+    pub data: &'static mut [u32],
+}
+
+impl Display {
+    fn new(width: usize, height: usize, data: &'static mut [u32]) -> Self {
+        Display {
+            width: width,
+            height: height,
+            data: data,
+        }
+    }
+}
diff --git a/arch/x86_64/src/lib.rs b/arch/x86_64/src/lib.rs
index 2bb0cb9..8faf3e7 100644
--- a/arch/x86_64/src/lib.rs
+++ b/arch/x86_64/src/lib.rs
@@ -124,6 +124,9 @@ pub mod acpi;
 /// Context switching
 pub mod context;
 
+/// Display handling
+pub mod display;
+
 /// Memcpy, memmove, etc.
 pub mod externs;
 
diff --git a/arch/x86_64/src/start.rs b/arch/x86_64/src/start.rs
index bb35b84..1b80e93 100644
--- a/arch/x86_64/src/start.rs
+++ b/arch/x86_64/src/start.rs
@@ -7,6 +7,7 @@ use core::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, AtomicUsize, ATOMIC_USIZE
 
 use acpi;
 use allocator::{HEAP_START, HEAP_SIZE};
+use display;
 use externs::memset;
 use gdt;
 use idt;
@@ -90,6 +91,9 @@ pub unsafe extern fn kstart() -> ! {
             assert_eq!(TDATA_TEST_NONZERO, 0xFFFFFFFFFFFFFFFE);
         }
 
+        // Initialize display
+        display::init(&mut active_table);
+
         // Reset AP variables
         AP_COUNT.store(0, Ordering::SeqCst);
         BSP_READY.store(false, Ordering::SeqCst);