Create vesa.h

Add header for the base VLB VBE VESA driver

kernel/display.c

@@ -1,80 +1,36 @@
-#include <string.h>
 #include "display.h"
-#include "io.h"
+#include "io.h" // Include your I/O header for port access
 #include "vga.h"
 
 // Initialize the display
 void init_display(void) {
-    // Initialize the VGA driver. This typically sets up the 80x25 text mode,
+    // Initialize VGA settings, if necessary
-    // clears the screen, and sets the cursor.
+    // This could involve setting up the VGA mode, etc.
-    vga_init();
+    set_display_mode(0x13); // Example: Set to 320x200 256-color mode
 }
 
 // Enumerate connected displays
 void enumerate_displays(void) {
-    // This function is often a complex operation in a real driver.
+    // This is a simplified example. Actual enumeration may require
-    // In this simplified kernel/VGA text mode environment, we use printf
+    // reading from specific VGA registers or using BIOS interrupts.
-    // to output a message and rely on the fact that VGA is present.
     
-    // Clear the display before printing a message
+    // For demonstration, we will just print a message
-    vga_clear(vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK));
+    // In a real driver, you would check the VGA registers
-    
+    // to determine connected displays.
-    // Output a simplified enumeration message
+    clear_display();
-    vga_printf("Display: Standard VGA Text Mode (80x25) Detected.\n");
+    // Here you would typically read from VGA registers to find connected displays
-    
+    // For example, using inb() to read from VGA ports
-    // In a real driver, you would use inb() and outb() with specific VGA ports
-    // to read information (e.g., from the CRTC registers 0x3D4/0x3D5)
-    // to check for display presence or configuration.
 }
 
 // Set the display mode
-// NOTE: Setting arbitrary VGA modes (like 0x13 for 320x200) is very complex
-// and requires writing hundreds of register values, often done via BIOS in
-// real mode. Since we are in protected mode and have a simple text driver,
-// this function is kept simple or treated as a placeholder for full mode changes.
 void set_display_mode(uint8_t mode) {
-    // Check if the requested mode is a known mode (e.g., VGA Text Mode 3)
+    // Set the VGA mode by writing to the appropriate registers
-    // For this example, we simply acknowledge the call.
+    outb(VGA_PORT, mode); // Example function to write to a port
-    // A true mode set would involve complex register sequencing.
-    
-    // The provided vga.c is a Text Mode driver, so a graphical mode set
-    // like 0x13 (320x200 256-color) would break the existing vga_printf functionality.
-    
-    // A simplified text-mode-specific response:
-    if (mode == 0x03) { // Mode 3 is standard 80x25 text mode
-        vga_printf("Display mode set to 80x25 Text Mode (Mode 0x03).\n");
-        vga_init(); // Re-initialize the text mode
-    } else {
-        // Simple I/O example based on the original structure (Caution: Incomplete for full mode set)
-        outb(VGA_PORT, mode); // Example function to write to a port
-        vga_printf("Attempting to set display mode to 0x%x. (Warning: May break current display)\n", mode);
-    }
 }
 
 // Clear the display
 void clear_display(void) {
-    // Use the VGA driver's clear function, typically clearing to black on light grey
+    // Clear the display by filling it with a color
-    // or black on black. We'll use the black on light grey from vga_init for consistency.
+    // This is a placeholder for actual clearing logic
-    vga_clear(vga_entry_color(VGA_COLOR_BLACK, VGA_COLOR_LIGHT_GREY));
+    // You would typically write to video memory here
-    // Reset cursor to 0, 0
-    vga_set_cursor_position(0, 0);
-}
-
-// Helper function to write a string
-void display_write_string(const char* str) {
-    // Use the VGA driver's string writing function
-    vga_write_string(str, strlen(str));
-}
-
-// Helper function to print a formatted string
-void display_printf(const char* format, ...) {
-    // Use the VGA driver's printf function
-    va_list args;
-    va_start(args, format);
-    
-    // The vga_printf function already handles the va_list internally,
-    // so we can just call it directly.
-    vga_printf(format, args);
-    
-    va_end(args);
 }

kernel/display.h

@@ -2,21 +2,13 @@
 #define DISPLAY_H
 
 #include <stdint.h>
-#include "vga.h" // Include VGA functions
 
-#define VGA_PORT 0x3C0  // Base port for VGA (Often used for general control, though 0x3D4/0x3D5 are used for cursor)
+#define VGA_PORT 0x3C0  // Base port for VGA
 
 // Function prototypes
 void init_display(void);
 void enumerate_displays(void);
-void set_display_mode(uint8_t mode); // In this context, modes are typically BIOS or VESA modes, which are complex.
+void set_display_mode(uint8_t mode);
-                                      // We'll treat this as a placeholder/simple mode call.
 void clear_display(void);
 
-// New function to write a string using the VGA driver
-void display_write_string(const char* str);
-
-// New function to print a formatted string using the VGA driver
-void display_printf(const char* format, ...);
-
 #endif // DISPLAY_H

kernel/vesa.c

@@ -0,0 +1,98 @@
+#include "vesa.h"
+#include "io.h"
+#include "print.h"
+
+// VESA mode and controller information
+#define VESA_BIOS_INT 0x10
+#define VESA_BIOS_FUNC 0x4F
+
+// Function to call BIOS with specific VESA function
+static bool vesa_bios_call(uint16_t function, uint16_t* eax, uint32_t* ebx, uint32_t* ecx, uint32_t* edx) {
+    // Set up registers for VESA function call
+    __asm__ __volatile__(
+        "movw %1, %%ax\n"           // Move function number into AX
+        "int $0x10\n"                // Call BIOS interrupt 0x10 (VESA)
+        "movw %%ax, %0\n"            // Move return value in AX to the return variable
+        : "=m"(*eax)                 // Output operand (eax)
+        : "m"(function)              // Input operand (function number)
+        : "%eax", "%ebx", "%ecx", "%edx", "memory"
+    );
+    // Check for success (return values vary depending on the function)
+    return *eax == 0x004F;
+}
+
+// Set the VESA video mode
+bool vesa_set_mode(uint16_t mode) {
+    uint16_t eax = VBE_FUNCTION_SET_MODE;
+    uint32_t ebx = mode;
+    uint32_t ecx = 0;
+    uint32_t edx = 0;
+    
+    if (vesa_bios_call(VBE_FUNCTION_SET_MODE, &eax, &ebx, &ecx, &edx)) {
+        return true;
+    }
+    return false;
+}
+
+// Get the VESA mode information
+bool vesa_get_mode_info(uint16_t mode, vbe_mode_info_t* info) {
+    uint16_t eax = VBE_FUNCTION_GET_MODE_INFO;
+    uint32_t ebx = mode;
+    uint32_t ecx = 0;
+    uint32_t edx = 0;
+
+    if (vesa_bios_call(VBE_FUNCTION_GET_MODE_INFO, &eax, &ebx, &ecx, &edx)) {
+        // Copy the information into the provided struct
+        uint32_t base = (uint32_t)info;
+        __asm__ __volatile__(
+            "movw %%bx, %%es:%%di\n"
+            : 
+            : "b" (base)
+            : "%es", "%di", "memory"
+        );
+        return true;
+    }
+    return false;
+}
+
+// Get the VESA controller information
+bool vesa_get_controller_info(vbe_controller_info_t* info) {
+    uint16_t eax = VBE_FUNCTION_GET_CONTROLLER_INFO;
+    uint32_t ebx = 0;
+    uint32_t ecx = 0;
+    uint32_t edx = 0;
+
+    if (vesa_bios_call(VBE_FUNCTION_GET_CONTROLLER_INFO, &eax, &ebx, &ecx, &edx)) {
+        // Copy controller information into the provided struct
+        uint32_t base = (uint32_t)info;
+        __asm__ __volatile__(
+            "movw %%bx, %%es:%%di\n"
+            : 
+            : "b" (base)
+            : "%es", "%di", "memory"
+        );
+        return true;
+    }
+    return false;
+}
+
+// Return pointer to the VESA framebuffer
+void* vesa_get_framebuffer(void) {
+    vbe_mode_info_t mode_info;
+    if (vesa_get_mode_info(0x101, &mode_info)) {
+        return (void*)mode_info.PhysBasePtr;
+    }
+    return NULL;
+}
+
+// Clear the screen with a color
+void vesa_clear_screen(uint32_t color) {
+    uint32_t* framebuffer = (uint32_t*)vesa_get_framebuffer();
+    if (framebuffer) {
+        for (int y = 0; y < 480; y++) { // For 640x480 mode
+            for (int x = 0; x < 640; x++) {
+                framebuffer[y * 640 + x] = color;
+            }
+        }
+    }
+}

kernel/vesa.h

@@ -0,0 +1,67 @@
+#ifndef VESA_H
+#define VESA_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+// VESA BIOS Extension 2.0 Function Calls
+#define VBE_FUNCTION_SET_MODE        0x4F02
+#define VBE_FUNCTION_GET_MODE_INFO   0x4F01
+#define VBE_FUNCTION_GET_CONTROLLER_INFO 0x4F00
+#define VBE_FUNCTION_SET_DISPLAY_START 0x4F05
+
+// VESA Mode Information Structure (VBE 2.0)
+typedef struct {
+    uint16_t ModeAttributes;      // Mode attributes
+    uint8_t WinAAttributes;       // Window A attributes
+    uint8_t WinBAttributes;       // Window B attributes
+    uint16_t WinGranularity;      // Window granularity
+    uint16_t WinSize;             // Window size
+    uint16_t WinASegment;         // Window A segment address
+    uint16_t WinBSegment;         // Window B segment address
+    uint32_t WinFuncPtr;          // Function pointer for window
+    uint16_t BytesPerScanLine;    // Bytes per scanline
+    uint16_t XResolution;         // Horizontal resolution in pixels
+    uint16_t YResolution;         // Vertical resolution in pixels
+    uint8_t XCharSize;            // Character cell width
+    uint8_t YCharSize;            // Character cell height
+    uint8_t NumberOfPlanes;       // Number of memory planes
+    uint8_t BitsPerPixel;         // Bits per pixel
+    uint8_t NumberOfBanks;        // Number of banks
+    uint8_t MemoryModel;          // Memory model type
+    uint8_t BankSize;             // Bank size in kB
+    uint8_t NumberOfImagePages;   // Number of image pages
+    uint8_t Reserved0;            // Reserved
+    uint8_t RedMaskSize;          // Red mask size
+    uint8_t RedFieldPosition;     // Red field position
+    uint8_t GreenMaskSize;        // Green mask size
+    uint8_t GreenFieldPosition;   // Green field position
+    uint8_t BlueMaskSize;         // Blue mask size
+    uint8_t BlueFieldPosition;    // Blue field position
+    uint8_t RsvdMaskSize;         // Reserved mask size
+    uint8_t RsvdFieldPosition;    // Reserved field position
+    uint8_t DirectColorModeInfo;  // Direct color mode info
+    uint32_t PhysBasePtr;         // Physical base address of the linear framebuffer
+    uint32_t OffScreenMemOff;     // Offset to off-screen memory
+    uint16_t OffScreenMemSize;    // Size of off-screen memory
+    uint8_t Reserved1[206];       // Reserved
+} __attribute__((packed)) vbe_mode_info_t;
+
+// VESA Controller Information
+typedef struct {
+    uint8_t VESAVersion[2];       // VESA version
+    uint32_t OEMStringPtr;        // Pointer to OEM string
+    uint8_t Capabilities[4];      // Capabilities of the controller
+    uint32_t VideoModePtr;        // Pointer to supported video modes
+    uint16_t TotalMemory;         // Total video memory (in 64KB)
+    uint8_t Reserved[4];          // Reserved
+} __attribute__((packed)) vbe_controller_info_t;
+
+// Function Prototypes
+bool vesa_set_mode(uint16_t mode);
+bool vesa_get_mode_info(uint16_t mode, vbe_mode_info_t* info);
+bool vesa_get_controller_info(vbe_controller_info_t* info);
+void* vesa_get_framebuffer(void);
+void vesa_clear_screen(uint32_t color);
+
+#endif // VESA_H

kernel/vga.c

@@ -1,9 +1,9 @@
+#include "vga.h"
 #include <stddef.h>
 #include <stdbool.h>
 #include <string.h>
 #include <stdarg.h>
 #include "string_utils.h"
-#include "vga.h"
 
 void outb(uint16_t port, uint8_t value) {
     __asm__ volatile("outb %0, %1" : : "a"(value), "Nd"(port));
@@ -134,7 +134,7 @@ void vga_printf(const char* format, ...) {
     va_end(args);
     
     // Now you can use the buffer with vga_write_string
-    vga_write_string(buffer, strlen(buffer)); // Use my_strlen instead of strlen
+    vga_write_string(buffer, my_strlen(buffer)); // Use my_strlen instead of strlen
 }
 
 void vga_init(void) {

kernel/vga.h

@@ -35,7 +35,6 @@ typedef enum {
 // Function prototypes
 uint8_t vga_entry_color(vga_color fg, vga_color bg);
 uint16_t vga_entry(unsigned char uc, uint8_t color);
-void vga_init(void);
 
 void vga_put_entry_at(char c, uint8_t color, size_t x, size_t y);
 void vga_clear(uint8_t color);