Create ata.h

implement the base ata pio mode driver so that the filesystems like fat16, fat32 work. This is the header for that. It will need a iso9660 driver for cdrom etc optical media

kernel/ata.h

@@ -0,0 +1,43 @@
+#ifndef ATA_H
+#define ATA_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/* ATA I/O ports */
+#define ATA_PRIMARY_IO     0x1F0
+#define ATA_PRIMARY_CTRL   0x3F6
+
+/* ATA registers */
+#define ATA_REG_DATA       0x00
+#define ATA_REG_ERROR      0x01
+#define ATA_REG_FEATURES   0x01
+#define ATA_REG_SECCOUNT0  0x02
+#define ATA_REG_LBA0       0x03
+#define ATA_REG_LBA1       0x04
+#define ATA_REG_LBA2       0x05
+#define ATA_REG_HDDEVSEL   0x06
+#define ATA_REG_COMMAND    0x07
+#define ATA_REG_STATUS     0x07
+
+/* ATA commands */
+#define ATA_CMD_READ_PIO   0x20
+#define ATA_CMD_WRITE_PIO  0x30
+#define ATA_CMD_IDENTIFY   0xEC
+
+/* Status flags */
+#define ATA_SR_BSY         0x80
+#define ATA_SR_DRDY        0x40
+#define ATA_SR_DRQ         0x08
+#define ATA_SR_ERR         0x01
+
+/* Drive select */
+#define ATA_MASTER         0x00
+#define ATA_SLAVE          0x10
+
+/* Public API */
+bool ata_init(void);
+bool ata_read_sector(uint32_t lba, uint8_t* buffer);
+bool ata_write_sector(uint32_t lba, const uint8_t* buffer);
+
+#endif

kernel/vesa.c

@@ -1,112 +0,0 @@
-#include <stddef.h>
-#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 ax_ret;
-    
-    // Convert the 32-bit pointer to a Segment:Offset pair
-    // IMPORTANT: 'info' MUST be located in the first 1MB of RAM
-    uint32_t ptr = (uint32_t)info;
-    uint16_t segment = (uint16_t)((ptr >> 4) & 0xFFFF);
-    uint16_t offset  = (uint16_t)(ptr & 0x000F);
-
-    __asm__ __volatile__(
-        "push %%es\n\t"         // Save Protected Mode ES
-        "movw %1, %%es\n\t"     // Load the segment into ES
-        "int $0x10\n\t"         // BIOS Interrupt
-        "pop %%es\n\t"          // Restore Protected Mode ES
-        : "=a"(ax_ret)          // Result in AX
-        : "r"(segment),         // %1
-          "D"(offset),          // %2 (DI)
-          "a"((uint16_t)VBE_FUNCTION_GET_MODE_INFO), // AX (0x4F01)
-          "c"(mode)             // CX (The Mode Number)
-        : "memory", "cc"        // Removed %es from clobbers
-    );
-
-    return ax_ret == 0x004F;
-}
-
-bool vesa_get_controller_info(vbe_controller_info_t* info) {
-    uint16_t ax_ret;
-    
-    // We must use Segment:Offset for BIOS
-    uint32_t ptr = (uint32_t)info;
-    uint16_t segment = (uint16_t)((ptr >> 4) & 0xF000); // Base segment
-    uint16_t offset  = (uint16_t)(ptr & 0xFFFF);        // Offset
-
-    // Copy "VBE2" into signature to tell BIOS we want VBE 2.0+ info
-    info->Signature[0] = 'V';
-    info->Signature[1] = 'B';
-    info->Signature[2] = 'E';
-    info->Signature[3] = '2';
-
-    // To fix the error: Do not use %es in clobber. 
-    // Use a temporary register or a push/pop sequence if we MUST touch ES.
-    __asm__ __volatile__(
-        "push %%es\n\t"
-        "movw %1, %%es\n\t"
-        "int $0x10\n\t"
-        "pop %%es\n\t"
-        : "=a"(ax_ret)
-        : "r"(segment), "D"(offset), "a"(0x4F00)
-        : "memory", "cc" 
-    );
-
-    return ax_ret == 0x004F;
-}
-
-// 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

@@ -1,75 +0,0 @@
-#ifndef VESA_H
-#define VESA_H
-
-#include <stdint.h>
-#include <stdbool.h>
-#include <stddef.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 {
-    char Signature[4];             // Should be "VESA" (or "VBE2" for request)
-    uint16_t Version;              // VBE version; high byte is major, low is minor
-    uint32_t OEMStringPtr;         // Segment:Offset pointer to OEM string
-    uint32_t Capabilities;         // Capabilities of graphics controller
-    uint32_t VideoModePtr;         // Segment:Offset pointer to supported modes list
-    uint16_t TotalMemory;          // Number of 64KB memory blocks
-    uint16_t OEMSoftwareRev;       // VBE implementation Software revision
-    uint32_t OEMVendorNamePtr;     // Segment:Offset pointer to Vendor Name string
-    uint32_t OEMProductNamePtr;    // Segment:Offset pointer to Product Name string
-    uint32_t OEMProductRevPtr;     // Segment:Offset pointer to Product Revision string
-    uint8_t Reserved[222];         // Reserved for VBE implementation scratch area
-    uint8_t OEMData[256];          // Data area for OEM strings
-} __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