replace the VHD/diskpart disk image pipeline with a directory-based vvfat root, we'll see when it breaks, fix /O2, add an all_tests, generalize the fat32 driver into a fat 16+32 driver, change policy on volume drivers, collapse KCPU's fields into a single atomic KE_CPU_STATE state machine, move scheduler ticking to per-CPU LAPIC timers, gate verbose SMP topology logging behind selftest diagnostics and add SMP pool-checkpoint validation around AP admission, add checked intrusive list helpers behind a new KE_DEBUG_LIST_CHECKS flag, add ObInitializeObjectHeader/ObTryReferenceObject, add waitable display clock objects and a SYS_OPEN_DISPLAY_CLOCK syscall for vsync-style waits, refactor kernel input into a per-queue KE_INPUT_CONTEXT with its own key/mouse ring buffers and DPC-driven key repeat, add KeInputQueuePeekEvent/ReadEvent/WaitKey and a SYS_QUERY_GLOBAL_INPUT_STATE syscall, split the kernel pool allocator out of mm_virt, new video files!

code/drivers/fs/fat/fat_disk.h

@@ -0,0 +1,119 @@
+// FAT on-disk layout definitions shared by the FAT driver.
+
+#pragma once
+
+#include <stdint.h>
+
+#pragma pack(push, 1)
+
+typedef struct {
+    uint8_t  Jump[3];
+    char     OemId[8];
+    uint16_t BytesPerSector;
+    uint8_t  SectorsPerCluster;
+    uint16_t ReservedSectors;
+    uint8_t  NumFats;
+    uint16_t RootEntryCount;
+    uint16_t TotalSectors16;
+    uint8_t  MediaType;
+    uint16_t FatSize16;
+    uint16_t SectorsPerTrack;
+    uint16_t NumHeads;
+    uint32_t HiddenSectors;
+    uint32_t TotalSectors32;
+    uint32_t FatSize32;
+    uint16_t ExtFlags;
+    uint16_t FsVersion;
+    uint32_t RootCluster;
+    uint16_t FsInfoSector;
+    uint16_t BackupBootSector;
+    uint8_t  Reserved[12];
+    uint8_t  DriveNumber;
+    uint8_t  Reserved1;
+    uint8_t  BootSignature;
+    uint32_t VolumeId;
+    char     VolumeLabel[11];
+    char     FsType[8];
+} BPB;
+
+typedef struct {
+    char     Name[8];
+    char     Ext[3];
+    uint8_t  Attr;
+    uint8_t  Reserved;
+    uint8_t  CrtTimeTenth;
+    uint16_t CrtTime;
+    uint16_t CrtDate;
+    uint16_t LastAccDate;
+    uint16_t FirstClusterHi;
+    uint16_t WrtTime;
+    uint16_t WrtDate;
+    uint16_t FirstClusterLo;
+    uint32_t FileSize;
+} DIRENT;
+
+typedef struct {
+    uint8_t  Order;
+    uint16_t Name1[5];
+    uint8_t  Attr;
+    uint8_t  Type;
+    uint8_t  Checksum;
+    uint16_t Name2[6];
+    uint16_t FirstCluster;
+    uint16_t Name3[2];
+} LFN_ENTRY;
+
+typedef struct {
+    uint32_t Data1;
+    uint16_t Data2;
+    uint16_t Data3;
+    uint8_t  Data4[8];
+} EFI_GUID;
+
+typedef struct {
+    char     Signature[8];
+    uint32_t Revision;
+    uint32_t HeaderSize;
+    uint32_t HeaderCRC32;
+    uint32_t Reserved;
+    uint64_t MyLBA;
+    uint64_t AlternateLBA;
+    uint64_t FirstUsableLBA;
+    uint64_t LastUsableLBA;
+    EFI_GUID DiskGUID;
+    uint64_t PartitionEntryLBA;
+    uint32_t NumberOfPartitionEntries;
+    uint32_t SizeOfPartitionEntry;
+    uint32_t PartitionEntryArrayCRC32;
+} GPT_HEADER;
+
+typedef struct {
+    EFI_GUID PartitionTypeGUID;
+    EFI_GUID UniquePartitionGUID;
+    uint64_t StartingLBA;
+    uint64_t EndingLBA;
+    uint64_t Attributes;
+    uint16_t PartitionName[36];
+} GPT_ENTRY;
+
+#pragma pack(pop)
+
+#define ATTR_VOLUME_ID   0x08
+#define ATTR_DIRECTORY   0x10
+#define ATTR_ARCHIVE     0x20
+#define ATTR_LFN         0x0F
+#define FAT_NTRES_BASE_LOWER 0x08u
+#define FAT_NTRES_EXT_LOWER  0x10u
+#define FAT_FREE       0x00000000u
+#define FAT16_EOC      0x0000FFF8u
+#define FAT16_EOC_MARK 0x0000FFFFu
+#define FAT32_EOC      0x0FFFFFF8u
+#define FAT32_EOC_MARK 0x0FFFFFFFu
+#define FAT_FIXED_ROOT_CLUSTER 0xFFFFFFFEu
+
+typedef enum FAT_VARIANT {
+    FatVariantUnsupported = 0,
+    FatVariant12,
+    FatVariant16,
+    FatVariant32,
+} FAT_VARIANT;