Commit Graph

3 Commits

Author SHA1 Message Date
AI
27b2042523 Implement mkfs.fat32 filesystem formatter app (AI)
Create a user-space utility that formats block devices with FAT32.
Writes all required on-disk structures sequentially:

- Boot sector (BPB) with BIOS Parameter Block at sector 0
- FSInfo sector at sector 1 with free cluster count/hint
- Backup boot sector at sector 6, backup FSInfo at sector 7
- Two FAT tables with entries 0-2 initialized (media marker,
  EOC markers, root directory cluster EOC)
- Root directory cluster with volume label entry

Geometry calculation:
- Sectors per cluster chosen based on volume size (1-32)
- FAT size computed using Microsoft's formula
- Supports volumes from 128 sectors (~64K) upward

Usage: mkfs.fat32 hdd1mbr1 14336 [LABEL]
The total sector count is required since there is no stat() syscall
yet. Users can find it via 'diskpart <dev> list'.

Also checked off diskpart in README (committed previously).
2026-02-23 16:33:12 +00:00
AI
7dc50aa57d Implement diskpart MBR partition editor app (AI)
Create a user-space diskpart utility that can view and modify MBR
partition tables on block devices accessible through /dev.

Features:
- list: displays all 4 partition slots with type, LBA start, size
- create <slot> <type> <start> <sectors>: creates a new partition
- delete <slot>: removes a partition entry
- activate/deactivate <slot>: sets or clears the bootable flag

The tool reads sector 0 (MBR) via VFS open/read, modifies the
partition table in memory, then writes it back via open/write.
Supports hex type codes and provides human-readable type names
for common partition types (FAT12/16/32, Linux, NTFS, etc.).

Usage: diskpart hdd1 create 1 0C 2048 14336
       diskpart hdd1 list
       diskpart hdd1 delete 2
2026-02-23 16:28:44 +00:00
AI
31740f7556 Implement floppy disk controller driver (AI)
Add Intel 82077AA-compatible floppy disk controller driver with:
- CMOS-based drive detection (register 0x10)
- FDC reset with DOR toggle and SPECIFY command
- Motor control with spin-up delay
- ISA DMA channel 2 setup for data transfers
- LBA-to-CHS conversion for 1.44MB geometry
- Single-sector read/write via DMA with 7-byte result phase
- Seek and recalibrate with sense interrupt verification
- IRQ 6 handler (vector 38) for command completion
- Devicefs integration as 'floppy' class block devices

The IRQ wait function detects whether interrupts are enabled
(EFLAGS IF bit) and temporarily enables them if needed, allowing
the driver to work during early init before the kernel calls STI.
The scheduler safely handles timer interrupts in this window since
no user processes exist yet.

Tested with QEMU: drive detected as 1.44M 3.5", registered as
/dev/floppy1, full boot succeeds with CD+HDD+floppy attached.
2026-02-23 15:19:42 +00:00