Create pci.c

kernel/display.c

@@ -1,79 +1,36 @@
 #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,
-    // clears the screen, and sets the cursor.
-    vga_init();
+    // Initialize VGA settings, if necessary
+    // This could involve setting up the VGA mode, etc.
+    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.
-    // In this simplified kernel/VGA text mode environment, we use printf
-    // to output a message and rely on the fact that VGA is present.
+    // This is a simplified example. Actual enumeration may require
+    // reading from specific VGA registers or using BIOS interrupts.
     
-    // Clear the display before printing a message
-    vga_clear(vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK));
-    
-    // Output a simplified enumeration message
-    vga_printf("Display: Standard VGA Text Mode (80x25) Detected.\n");
-    
-    // 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.
+    // For demonstration, we will just print a message
+    // In a real driver, you would check the VGA registers
+    // to determine connected displays.
+    clear_display();
+    // Here you would typically read from VGA registers to find connected displays
+    // For example, using inb() to read from VGA ports
 }
 
 // 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)
-    // For this example, we simply acknowledge the call.
-    // 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);
-    }
+    // Set the VGA mode by writing to the appropriate registers
+    outb(VGA_PORT, mode); // Example function to write to a port
 }
 
 // Clear the display
 void clear_display(void) {
-    // Use the VGA driver's clear function, typically clearing to black on light grey
-    // or black on black. We'll use the black on light grey from vga_init for consistency.
-    vga_clear(vga_entry_color(VGA_COLOR_BLACK, VGA_COLOR_LIGHT_GREY));
-    // 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, my_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);
+    // Clear the display by filling it with a color
+    // This is a placeholder for actual clearing logic
+    // You would typically write to video memory here
 }

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.
-                                      // We'll treat this as a placeholder/simple mode call.
+void set_display_mode(uint8_t mode);
 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/pci.c

@@ -0,0 +1,119 @@
+#include "pci.h"
+
+/* --- Internal I/O Helpers (If not defined in your kernel) --- */
+static inline void outl(uint16_t port, uint32_t val) {
+    asm volatile ("outl %0, %1" : : "a"(val), "Nd"(port));
+}
+
+static inline uint32_t inl(uint16_t port) {
+    uint32_t ret;
+    asm volatile ("inl %1, %0" : "=a"(ret) : "Nd"(port));
+    return ret;
+}
+
+/* --- Configuration Access Functions --- */
+
+uint32_t pci_config_read_dword(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset) {
+    uint32_t address = (uint32_t)((uint32_t)1 << 31) | 
+                       ((uint32_t)bus << 16) | 
+                       ((uint32_t)slot << 11) | 
+                       ((uint32_t)func << 8) | 
+                       (offset & 0xFC);
+    outl(PCI_CONFIG_ADDRESS, address);
+    return inl(PCI_CONFIG_DATA);
+}
+
+void pci_config_write_dword(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset, uint32_t data) {
+    uint32_t address = (uint32_t)((uint32_t)1 << 31) | 
+                       ((uint32_t)bus << 16) | 
+                       ((uint32_t)slot << 11) | 
+                       ((uint32_t)func << 8) | 
+                       (offset & 0xFC);
+    outl(PCI_CONFIG_ADDRESS, address);
+    outl(PCI_CONFIG_DATA, data);
+}
+
+/* To read a word or byte, we read the Dword and shift/mask */
+uint16_t pci_config_read_word(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset) {
+    uint32_t dword = pci_config_read_dword(bus, slot, func, offset);
+    return (uint16_t)((dword >> ((offset & 2) * 8)) & 0xFFFF);
+}
+
+uint8_t pci_config_read_byte(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset) {
+    uint32_t dword = pci_config_read_dword(bus, slot, func, offset);
+    return (uint8_t)((dword >> ((offset & 3) * 8)) & 0xFF);
+}
+
+/* --- BAR Decoding Logic --- */
+
+pci_bar_t pci_get_bar(uint8_t bus, uint8_t slot, uint8_t func, uint8_t bar_index) {
+    pci_bar_t bar = {0};
+    uint8_t offset = PCI_REG_BAR0 + (bar_index * 4);
+    
+    uint32_t initial_val = pci_config_read_dword(bus, slot, func, offset);
+    
+    // The Size Masking Trick
+    pci_config_write_dword(bus, slot, func, offset, 0xFFFFFFFF);
+    uint32_t mask = pci_config_read_dword(bus, slot, func, offset);
+    pci_config_write_dword(bus, slot, func, offset, initial_val); // Restore
+    
+    if (initial_val & 0x1) {
+        // I/O Space BAR
+        bar.is_io = true;
+        bar.base_address = initial_val & 0xFFFFFFFC;
+        bar.size = ~(mask & 0xFFFFFFFC) + 1;
+    } else {
+        // Memory Space BAR
+        bar.is_io = false;
+        bar.base_address = initial_val & 0xFFFFFFF0;
+        bar.is_prefetchable = (initial_val & 0x8) != 0;
+        bar.size = ~(mask & 0xFFFFFFF0) + 1;
+    }
+    
+    return bar;
+}
+
+/* --- Enumeration and Discovery --- */
+
+void pci_check_function(uint8_t bus, uint8_t slot, uint8_t func) {
+    uint16_t vendor_id = pci_config_read_word(bus, slot, func, PCI_REG_VENDOR_ID);
+    if (vendor_id == 0xFFFF) return; 
+
+    uint16_t device_id = pci_config_read_word(bus, slot, func, PCI_REG_DEVICE_ID);
+    uint8_t class_code = pci_config_read_byte(bus, slot, func, PCI_REG_CLASS);
+    
+    /* Optional: Set Master Latency Timer if it is 0. 
+       A value of 32 (0x20) or 64 (0x40) is typical. 
+    */
+    uint8_t latency = pci_config_read_byte(bus, slot, func, PCI_REG_LATENCY_TIMER);
+    if (latency == 0) {
+        // pci_config_write_byte would be needed here, or write a dword with the byte modified
+        uint32_t reg_0c = pci_config_read_dword(bus, slot, func, 0x0C);
+        reg_0c |= (0x20 << 8); // Set latency to 32
+        pci_config_write_dword(bus, slot, func, 0x0C, reg_0c);
+    }
+
+    // Replace with your kernel's print/logging function
+    // printf("Found PCI Device: %x:%x Class: %x at %d:%d:%d\n", vendor_id, device_id, class_code, bus, slot, func);
+}
+
+void pci_init(void) {
+    for (uint16_t bus = 0; bus < 256; bus++) {
+        for (uint8_t slot = 0; slot < 32; slot++) {
+            // Check Function 0 first
+            uint16_t vendor = pci_config_read_word(bus, slot, 0, PCI_REG_VENDOR_ID);
+            if (vendor == 0xFFFF) continue;
+
+            pci_check_function(bus, slot, 0);
+
+            // Check if this is a multi-function device
+            uint8_t header_type = pci_config_read_byte(bus, slot, 0, PCI_REG_HEADER_TYPE);
+            if (header_type & 0x80) {
+                // Check functions 1-7
+                for (uint8_t func = 1; func < 8; func++) {
+                    pci_check_function(bus, slot, func);
+                }
+            }
+        }
+    }
+}

kernel/pci.h

@@ -0,0 +1,60 @@
+#ifndef PCI_H
+#define PCI_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/* I/O Ports for PCI Configuration Mechanism #1 */
+#define PCI_CONFIG_ADDRESS 0xCF8
+#define PCI_CONFIG_DATA    0xCFC
+
+/* Common PCI Configuration Register Offsets */
+#define PCI_REG_VENDOR_ID       0x00
+#define PCI_REG_DEVICE_ID       0x02
+#define PCI_REG_COMMAND         0x04
+#define PCI_REG_STATUS          0x06
+#define PCI_REG_REVISION_ID     0x08
+#define PCI_REG_PROG_IF         0x09
+#define PCI_REG_SUBCLASS        0x0A
+#define PCI_REG_CLASS           0x0B
+#define PCI_REG_CACHE_LINE_SIZE 0x0C
+#define PCI_REG_LATENCY_TIMER   0x0D
+#define PCI_REG_HEADER_TYPE     0x0E
+#define PCI_REG_BIST            0x0F
+#define PCI_REG_BAR0            0x10
+#define PCI_REG_BAR1            0x14
+#define PCI_REG_BAR2            0x18
+#define PCI_REG_BAR3            0x1C
+#define PCI_REG_BAR4            0x20
+#define PCI_REG_BAR5            0x24
+#define PCI_REG_INTERRUPT_LINE  0x3C
+
+typedef struct {
+    uint32_t base_address;
+    uint32_t size;
+    bool     is_io;
+    bool     is_prefetchable; // Only for Memory BARs
+} pci_bar_t;
+
+typedef struct {
+    uint8_t  bus;
+    uint8_t  device;
+    uint8_t  function;
+    uint16_t vendor_id;
+    uint16_t device_id;
+    uint8_t  class_code;
+    uint8_t  subclass;
+    uint8_t  interrupt_line;
+} pci_dev_t;
+
+/* Function Prototypes */
+uint32_t pci_config_read_dword(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
+void     pci_config_write_dword(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset, uint32_t data);
+
+uint16_t pci_config_read_word(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
+uint8_t  pci_config_read_byte(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
+
+pci_bar_t pci_get_bar(uint8_t bus, uint8_t slot, uint8_t func, uint8_t bar_index);
+void      pci_init(void);
+
+#endif