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nt-lite/code/kernel/io_file.h
T

139 lines
6.6 KiB
C

#pragma once
// io_file.h - VFS layer
// Filesystem drivers register an IO_FILESYSTEM vtable via IoRegisterFilesystem.
// Kernel and user code open files through IoOpenFile.
#include <stdint.h>
#include <stddef.h>
#include <ke_status.h>
#include <ob_object.h>
// ---------------------------------------------------------------------------
// KDIR_ENTRY - one directory entry returned by ReadDir / SYS_READ_DIR
// Attribute flags match FAT32/Win32: ATTR_DIRECTORY=0x10, ATTR_ARCHIVE=0x20
// ---------------------------------------------------------------------------
#define KDIR_NAME_MAX 260
typedef struct KDIR_ENTRY {
char Name[KDIR_NAME_MAX]; // null-terminated filename
uint8_t Attr; // FAT attribute byte (0x10=dir, 0x20=file)
uint32_t FileSize; // 0 for directories
} KDIR_ENTRY;
// ---------------------------------------------------------------------------
// Filesystem driver vtable - filled in by fat32.sys (or any future fs driver)
// ---------------------------------------------------------------------------
typedef struct IO_FILESYSTEM {
// Open a file by absolute path (e.g. "apps\\shell.exe").
// Returns an opaque per-file driver cookie in* fileCtx.
KSTATUS (*Open)(struct IO_FILESYSTEM* fs,
const char* path, void **fileCtx);
// Read up to 'size' bytes at 'offset' into 'buf'.
// Sets* bytesRead to actual bytes copied.
KSTATUS (*Read)(struct IO_FILESYSTEM* fs, void* fileCtx,
uint64_t offset, void* buf,
size_t size, size_t* bytesRead);
KSTATUS (*Write)(struct IO_FILESYSTEM* fs, void* fileCtx,
uint64_t offset, const void* buf,
size_t size, size_t* bytesWritten);
// Create a new file at 'path'; returns an open fileCtx on success.
KSTATUS (*Create)(struct IO_FILESYSTEM* fs, const char* path,
void** fileCtx);
// Delete the file at 'path'.
KSTATUS (*Delete)(struct IO_FILESYSTEM* fs, const char* path);
// Truncate or extend the file to exactly 'newSize' bytes.
KSTATUS (*Truncate)(struct IO_FILESYSTEM* fs, void* fileCtx,
uint64_t newSize);
// Return the file size in bytes.
uint64_t (*GetSize)(struct IO_FILESYSTEM* fs, void* fileCtx);
// Release any resources the driver allocated for fileCtx.
void (*Close)(struct IO_FILESYSTEM* fs, void* fileCtx);
// Optional driver-private data.
void* DriverCtx;
// ---------------------------------------------------------------------------
// Directory enumeration (optional - may be NULL if not supported)
// ---------------------------------------------------------------------------
// Open a directory iterator for 'dirPath' (relative or drive-prefixed).
// Returns an opaque per-iteration driver cookie in *dirCtx.
KSTATUS (*OpenDir)(struct IO_FILESYSTEM* fs,
const char* dirPath, void** dirCtx);
// Advance to the next entry.
// Fills 'out' with name, attributes, and size.
// Returns STATUS_NO_MORE_FILES when the directory is exhausted.
KSTATUS (*ReadDir)(struct IO_FILESYSTEM* fs, void* dirCtx,
struct KDIR_ENTRY* out);
// Release resources allocated by OpenDir.
void (*CloseDir)(struct IO_FILESYSTEM* fs, void* dirCtx);
} IO_FILESYSTEM;
// ---------------------------------------------------------------------------
// FILE_OBJECT - the kernel object returned to callers
// ---------------------------------------------------------------------------
typedef struct FILE_OBJECT {
OBJECT Header; // must be first
IO_FILESYSTEM* Fs;
void* FileCtx; // driver cookie
uint64_t Size;
uint64_t Offset; // current position for sequential reads
} FILE_OBJECT;
// ---------------------------------------------------------------------------
// DIR_OBJECT - kernel object for an open directory iterator
// ---------------------------------------------------------------------------
typedef struct DIR_OBJECT {
OBJECT Header; // must be first
IO_FILESYSTEM* Fs;
void* DirCtx; // driver cookie (opaque iteration state)
} DIR_OBJECT;
typedef struct IO_VOLUME_PARAMS {
uint8_t DiskIndex; // which disk in HAL_DISK table
uint64_t PartitionLba; // starting LBA of this partition
uint64_t PartitionSize; // sectors, for bounds checking
} IO_VOLUME_PARAMS;
// ---------------------------------------------------------------------------
// Registration - called by fat32.sys from DriverEntry
// ---------------------------------------------------------------------------
// driveIndex matches the index passed to IoRegisterDisk.
__declspec(dllexport) KSTATUS IoRegisterFilesystem(uint8_t driveIndex, IO_FILESYSTEM* fs, const IO_VOLUME_PARAMS *vol);
// ---------------------------------------------------------------------------
// Kernel-side API
// ---------------------------------------------------------------------------
__declspec(dllexport) KSTATUS IoOpenFile(const char* path, FILE_OBJECT **out);
__declspec(dllexport) KSTATUS IoReadFile(FILE_OBJECT* file, void* buf,
size_t size, size_t* bytesRead);
__declspec(dllexport) KSTATUS IoWriteFile (FILE_OBJECT* file, const void* buf,
size_t size, size_t* bytesWritten);
__declspec(dllexport) KSTATUS IoCreateFile (const char* path, FILE_OBJECT** out);
__declspec(dllexport) KSTATUS IoDeleteFile (const char* path);
__declspec(dllexport) KSTATUS IoTruncateFile(FILE_OBJECT* file, uint64_t newSize);
__declspec(dllexport) KSTATUS IoSeekFile(FILE_OBJECT* file, uint64_t offset);
__declspec(dllexport) uint64_t IoGetFileSize(FILE_OBJECT* file);
__declspec(dllexport) void IoCloseFile(FILE_OBJECT* file);
// ---------------------------------------------------------------------------
// Directory enumeration API
// ---------------------------------------------------------------------------
__declspec(dllexport) KSTATUS IoOpenDir (const char* dirPath, DIR_OBJECT** out);
__declspec(dllexport) KSTATUS IoReadDir (DIR_OBJECT* dir, KDIR_ENTRY* entryOut);
__declspec(dllexport) void IoCloseDir(DIR_OBJECT* dir);
// ---------------------------------------------------------------------------
// Current Working Directory
// ---------------------------------------------------------------------------
__declspec(dllexport) KSTATUS IoSetCwd(const char* path);
__declspec(dllexport) KSTATUS IoGetCwd(char* buf, size_t size);