CompactFlash Socket

The BE-300 has a Type I CompactFlash slot, managed through the VRC4173 companion chip via PCMCIA-compatible registers.

Status Register

Address	Kseg1 Address	Function
0x0A001000	0xAA001000	CF status register

Status register values:

Value	Meaning
0x04	Card inserted
0x0C	Card removed (or no card)

Interrupt Path

CompactFlash events (card insertion, removal, I/O ready) generate interrupts through the GIRQ0 sub-cascade:

1. CF state change or I/O ready
2. VRC4173 signals via GIRQ0 sub-cascade
3. GIU line 0 asserts
4. GIUINTLREG (0xAF000088) bit 0 set
5. Handler reads 0xAA000004 for sub-source identification

Both state-change (insert/remove) and level (I/O ready) interrupts are supported.

Usage

CyaCE Bootloader

The CyaCE bootloader reads Linux kernels and ramdisk images from a FAT-formatted CompactFlash card. This was the primary method for booting Linux on the BE-300 from a running Windows CE session.

NANDWRITER

The NANDWRITER recovery tool (NANDWRITER.bin) reads firmware images from a FAT-formatted CF card:

• KLOADER.bin -- SPL bootloader
• All_nand.bin -- NK.exe kernel + FAT16 filesystem
• nk.cpk -- Alternate compressed NK format

NANDWRITER writes these images directly to NAND flash to restore a non-booting device.

Linux Support

The Linux4.BE kernels did not include CompactFlash driver support. CF was only accessible under Windows CE.