More progress; writing to EGA text framebuffer now works.

kernel/config.aphro.example

@@ -1,5 +1,5 @@
-# config.aphro for aphrodite devel-b3558c2-out-of-tree
+# config.aphro for aphrodite devel-461136c-out-of-tree
-CFG_VERSION=devel-b3558c2-out-of-tree
+CFG_VERSION=devel-461136c-out-of-tree
 CONT_WITH_DIFFERENT_VERSION=false
 
 # Begin metadata
@@ -17,9 +17,9 @@ CONFIG_DISABLE_MULTIBOOT2_SUPPORT=false
 CONFIG_PREUSER_HALT_ON_PANIC=true
 CONFIG_PREUSER_SPIN_ON_PANIC=false
 
-CONFIG_PREUSER_EXIT_LOOP_ON_INVALID_LENGTH=false
+CONFIG_PREUSER_EXIT_LOOP_ON_INVALID_LENGTH=true
-CONFIG_PREUSER_PANIC_ON_INVALID_LENGTH=true
+CONFIG_PREUSER_PANIC_ON_INVALID_LENGTH=false
-CONFIG_PREUSER_WARN_ON_INVALID_LENGTH=true
+CONFIG_PREUSER_WARN_ON_INVALID_LENGTH=false
 CONFIG_PREUSER_ERROR_ON_INVALID_LENGTH=true
 
 # Whether to output various levels of messages.

kernel/get_version

@@ -0,0 +1,10 @@
+set -e
+
+DIR="${BASH_SOURCE%/*}"
+if [[ ! -d "$DIR" ]]; then DIR="$PWD"; fi
+
+. "$DIR/functions"
+
+get_version
+
+echo $VERSION

kernel/grub/boot/grub/grub.cfg

@@ -1,8 +1,8 @@
 set timeout=15
 set default=0
 
-menuentry "Aphrodite" --class aphrodite --class kernel --class os $menuentry_id_option 'aphrodite-basic-devel-b3558c2-out-of-tree' {
+menuentry "Aphrodite" --class aphrodite --class kernel --class os $menuentry_id_option 'aphrodite-basic-devel-461136c-out-of-tree' {
-    echo 'Loading Aphrodite aphrodite-devel-b3558c2-out-of-tree ...'
+    echo 'Loading Aphrodite aphrodite-devel-461136c-out-of-tree ...'
     multiboot2 /boot/aphrodite.kernel
     boot
 }

kernel/src/include/arch/x86/egatext.rs

@@ -0,0 +1,71 @@
+//! Stuff for writing and reading to the EGA text buffer.
+#![cfg(any(target_arch = "x86"))]
+
+/// Information about the framebuffer.
+#[derive(Clone, Copy)]
+pub struct FramebufferInfo {
+    /// A pointer to the framebuffer.
+    pub address: u64,
+    /// The pitch of the framebuffer (i.e. the number of bytes in each row).
+    pub pitch: u32,
+    /// The width of the framebuffer.
+    pub width: u32,
+    /// The height of the framebuffer.
+    pub height: u32,
+    /// Bits per pixel.
+    pub bpp: u8,
+}
+
+/// Returned when the provided position is invalid in the X direction.
+pub const ERR_INVALID_X: i16 = -1;
+/// Returned when the provided position is invalid in the Y direction.
+pub const ERR_INVALID_Y: i16 = -2;
+
+
+/// White text on a black background.
+pub const WHITE_ON_BLACK: u8 = 0b00000111;
+/// Black text on a black background.
+pub const BLACK_ON_BLACK: u8 = 0b00000000;
+
+impl FramebufferInfo {
+    /// Writes a character to the screen.
+    pub fn write_char(self, pos: (u32, u32), char: u8, color: u8) -> Result<(), crate::Error<'static>> {
+        if pos.0>self.width {
+            return Err(crate::Error::new("Invalid X position", ERR_INVALID_X));
+        }
+        if pos.1>self.height {
+            return Err(crate::Error::new("Invalid Y position", ERR_INVALID_Y));
+        }
+        unsafe {
+            let mut addr = self.address as usize;
+            addr += (pos.1*self.pitch) as usize;
+            addr += (pos.0*(self.bpp as u32/8)) as usize;
+            let base_ptr = addr as *mut u16;
+            (*base_ptr) = ((color as u16)<<8) | (char as u16);
+        }
+        Ok(())
+    }
+
+    /// Clears the screen.
+    pub fn clear_screen(self, color: u8) {
+        for x in 0..self.width {
+            for y in 0..self.height {
+                self.write_char((x, y), b' ', color).unwrap();
+            }
+        }
+    }
+
+    /// Writes a &str to the screen.
+    pub fn write_str(self, pos: (u32, u32), str: &str, color: u8) -> Result<(), crate::Error<'static>> {
+        let (mut x, mut y) = pos;
+        for char in str.as_bytes() {
+            self.write_char((x, y), *char, color)?;
+            x += 1;
+            if x>self.width {
+                x -= self.width;
+                y += 1;
+            }
+        }
+        Ok(())
+    }
+}

kernel/src/include/arch/x86/mod.rs

@@ -6,6 +6,7 @@ use core::arch::asm;
 pub mod interrupts;
 pub mod ports;
 pub mod output;
+pub mod egatext;
 
 mod constants;
 

kernel/src/include/errors.rs

@@ -6,6 +6,13 @@ pub struct Error<'a> {
     code: i16
 }
 
+impl<'a> Error<'a> {
+    /// Creates a new error.
+    pub fn new(message: &'a str, code: i16) -> Self {
+        Error { message, code }
+    }
+}
+
 impl core::fmt::Debug for Error<'_> {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         f.write_str(core::str::from_utf8(&crate::i16_as_u8_slice(self.code)).unwrap())?;

kernel/src/include/multiboot2.rs

@@ -26,7 +26,6 @@ impl core::ops::Index<usize> for CString {
 
 /// Used for Multiboot2 tags. This shouldn't be used after a [BootInfo] struct has been initalized, but it still can be used.
 #[repr(C)]
-#[repr(align(1))] // may or may not be necessary, but I'm not taking chances
 #[derive(Clone)]
 pub struct Tag {
     /// The type of the tag.
@@ -37,7 +36,6 @@ pub struct Tag {
 
 /// The root tag. The official Multiboot2 name is literally the "fixed part" of the tags, so I made a better name.
 #[repr(C)]
-#[repr(align(1))] // may or may not be necessary, but I'm not taking chances
 #[derive(Clone)]
 pub struct RootTag {
     /// The total length between the root tag and the terminating tag.
@@ -61,7 +59,6 @@ pub struct Module {
 
 /// One memory section provided by a Multiboot2 bootloader.
 #[repr(C)]
-#[repr(align(1))] // may or may not be necessary, but I'm not taking chances
 #[derive(Clone)]
 pub struct MemorySection {
     /// The base address of the section.
@@ -78,7 +75,6 @@ pub struct MemorySection {
 /// The raw memory map provided by a Multiboot2 bootloader. This is interpreted
 /// into a [MemoryMap].
 #[repr(C)]
-#[repr(align(1))] // may or may not be necessary, but I'm not taking chances
 pub struct RawMemoryMap {
     /// The type of the tag.
     pub tag_type: u32,
@@ -107,7 +103,6 @@ pub struct MemoryMap {
 
 /// A color descriptor for [ColorInfo::Palette].
 #[repr(C)]
-#[repr(align(1))] // may or may not be necessary, but I'm not taking chances
 #[derive(Clone, Copy)]
 pub struct PaletteColorDescriptor {
     /// The red value
@@ -120,7 +115,6 @@ pub struct PaletteColorDescriptor {
 
 /// Information about color, for use in [FramebufferInfo].
 #[repr(u8)]
-#[repr(align(1))] // may or may not be necessary, but I'm not taking chances
 #[derive(Clone, Copy)]
 pub enum ColorInfo {
     /// The palette for use on the framebuffer.
@@ -153,15 +147,10 @@ pub enum ColorInfo {
 
 /// Information about the framebuffer.
 #[repr(C)]
-#[repr(align(1))] // may or may not be necessary, but I'm not taking chances
 #[derive(Clone)]
 pub struct FramebufferInfo {
-    /// The raw pointer to the string.
-    pub ptr: *const u8,
-    /// The length of the string, excluding the null byte(\0) at the end.
-    pub len: usize,
     /// A pointer to the framebuffer.
-    pub address: *mut u8,
+    pub address: u64,
     /// The pitch of the framebuffer (i.e. the number of bytes in each row).
     pub pitch: u32,
     /// The width of the framebuffer.
@@ -175,7 +164,7 @@ pub struct FramebufferInfo {
     /// Reserved space. Ignore.
     reserved: u8,
 
-    // Color info after this; we need separate structs for each colorinfo and
+    // Color info after this; we need separate structs for each colorinfo as
     // we have to understand the format the bootloader gives us.
 }
 

kernel/src/internal/arch/x86/entry.rs

@@ -10,6 +10,8 @@
 use core::{arch::asm, ffi::CStr, panic::PanicInfo};
 use aphrodite::multiboot2::{BootInfo, CString, ColorInfo, FramebufferInfo, MemoryMap, PaletteColorDescriptor, RawMemoryMap, RootTag, Tag};
 use aphrodite::arch::x86::output::*;
+use aphrodite::arch::x86::egatext as egatext;
+use egatext::*;
 
 #[cfg(not(CONFIG_DISABLE_MULTIBOOT2_SUPPORT))]
 #[unsafe(link_section = ".multiboot2")]
@@ -161,33 +163,33 @@ extern "C" fn _start() -> ! {
                             // ...before the BootInfo's bootloader_name is set.
                         },
                         8 => { // Framebuffer info
-                            if current_tag.tag_len < 31 { // Unexpected size, something is probably up
+                            if current_tag.tag_len < 32 { // Unexpected size, something is probably up
-                                panic!("size of framebuffer info tag < 31");
+                                panic!("size of framebuffer info tag < 32");
                             }
-                            let framebufferinfo: *const FramebufferInfo = ptr as *const FramebufferInfo;
+                            let framebufferinfo: *const FramebufferInfo = (ptr as usize + size_of::<Tag>()) as *const FramebufferInfo;
                             let colorinfo: ColorInfo;
                             match (*framebufferinfo).fb_type {
                                 0 => { // Indexed
                                     colorinfo = ColorInfo::Palette {
-                                        num_colors: *((ptr + 40) as *const u32),
+                                        num_colors: *((ptr + 32) as *const u32),
-                                        palette: (ptr + 44) as *const PaletteColorDescriptor
+                                        palette: (ptr + 36) as *const PaletteColorDescriptor
                                     };
                                 },
                                 1 => { // RGB
                                     colorinfo = ColorInfo::RGBColor {
-                                        red_field_position: *((ptr + 40) as *const u8),
+                                        red_field_position: *((ptr + 32) as *const u8),
-                                        red_mask_size: *((ptr + 41) as *const u8),
+                                        red_mask_size: *((ptr + 33) as *const u8),
-                                        green_field_position: *((ptr + 42) as *const u8),
+                                        green_field_position: *((ptr + 34) as *const u8),
-                                        green_mask_size: *((ptr + 43) as *const u8),
+                                        green_mask_size: *((ptr + 35) as *const u8),
-                                        blue_field_position: *((ptr + 44) as *const u8),
+                                        blue_field_position: *((ptr + 36) as *const u8),
-                                        blue_mask_size: *((ptr + 45) as *const u8)
+                                        blue_mask_size: *((ptr + 37) as *const u8)
                                     }
                                 },
                                 2 => { // EGA Text
                                     colorinfo = ColorInfo::EGAText;
                                 },
                                 _ => {
-                                    unreachable!();
+                                    panic!("unknown color info type")
                                 }
                             }
                             BI.framebuffer_info = Some((*framebufferinfo).clone());
@@ -233,6 +235,8 @@ extern "C" fn _start() -> ! {
     unsafe {
         if BI.framebuffer_info.clone().is_some() {
             let framebuffer_info = BI.framebuffer_info.clone().unwrap();
+            let color_info = BI.color_info.clone().unwrap();
+
             sdebugs("Framebuffer width: ");
             sdebugbnpln(&aphrodite::u32_as_u8_slice(framebuffer_info.width));
             sdebugs("Framebuffer height: ");
@@ -244,9 +248,40 @@ extern "C" fn _start() -> ! {
             sdebugs("Framebuffer bpp: ");
             sdebugbnpln(&aphrodite::u8_as_u8_slice(framebuffer_info.bpp));
             sdebugs("Framebuffer type: ");
-            sdebugbnpln(&aphrodite::u8_as_u8_slice(framebuffer_info.fb_type));
+            sdebugbnp(&aphrodite::u8_as_u8_slice(framebuffer_info.fb_type));
-            sdebugs("Framebuffer length: ");
+
-            sdebugbnpln(&aphrodite::usize_as_u8_slice(framebuffer_info.len));
+            match framebuffer_info.fb_type {
+                0 => { // Indexed
+                    sdebugsnpln("(Indexed)");
+                    let ColorInfo::Palette{num_colors, palette: _} = color_info else { unreachable!() };
+                    sdebugs("Number of palette colors: ");
+                    sdebugbnpln(&aphrodite::u32_as_u8_slice(num_colors));
+                },
+                1 => { // RGB
+                    sdebugsnpln("(RGB)");
+                },
+                2 => { // EGA Text
+                    sdebugsnpln("(EGA Text)");
+                    sdebugsln("Attempting to output to screen(will then loop for 100000000 cycles)...");
+
+                    let ega = egatext::FramebufferInfo {
+                        address: framebuffer_info.address,
+                        pitch: framebuffer_info.pitch,
+                        width: framebuffer_info.width,
+                        height: framebuffer_info.height,
+                        bpp: framebuffer_info.bpp
+                    };
+                    ega.clear_screen(BLACK_ON_BLACK);
+                    ega.write_str((0, 0), "Test", WHITE_ON_BLACK).unwrap();
+
+                    for _ in 0..100000000 {
+                        asm!("nop")
+                    }
+                },
+                _ => {
+                    unreachable!();
+                }
+            }
         }
     }