현재 ez-pi에서 usb 사용하려는데 잘 안되네요.
우선 전에 답변 주신대로 ez-pi가 커널 2.6에서도 동작한다고 하셔서 아래 환경으로 진행중입니다.

커널 버젼: 2.6.21
램디스크 버젼: ramdisk-1.10.12M

이제 해야할 일이 mount 일 것 같아서 예전 ez-pi 매뉴얼을 참고로 하여
mount -t usbdevfs usbdevfs /proc/bus/usb
를 해주려고 하는데, no such device 뜨네요.
cat /proc/filesystems 로 확인해보니 커널 2.4에는 있었던 usbdevfs가 없긴 없네요.

이러한 mount 과정이 필요한건지 알려주시고,
어떻게 해야 하는 지 궁금합니다.
usb 쓰려는데 힘드네요.

참고로 쓰고자 하는 usb device는 USB FTDI Serial Converters 입니다.

<<<cat dmesg 첨부합니다.>>>
Linux version 2.6.21-falinux  (gcc version 3.4.3) #1 Tue9
CPU: XScale-PXA255 [69052d06] revision 6 (ARMv5TE), cr=0000397f
Machine: FALinux EZ-X5 Development Platform
Memory policy: ECC disabled, Data cache writeback
On node 0 totalpages: 16384
  DMA zone: 128 pages used for memmap
  DMA zone: 0 pages reserved
  DMA zone: 16256 pages, LIFO batch:3
  Normal zone: 0 pages used for memmap
Memory clock: 99.53MHz (*27)
Run Mode clock: 398.13MHz (*4)
Turbo Mode clock: 398.13MHz (*1.0, inactive)
CPU0: D VIVT undefined 5 cache
CPU0: I cache: 32768 bytes, associativity 32, 32 byte lines, 32 sets
CPU0: D cache: 32768 bytes, associativity 32, 32 byte lines, 32 sets
Built 1 zonelists.  Total pages: 16256
Kernel command line: EZBOOT mem=64M initrd=0xA0800000,5M root=/dev/ram ramdisk=
PID hash table entries: 256 (order: 8, 1024 bytes)
Console: colour dummy device 80x30
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
Memory: 64MB = 64MB total
Memory: 55808KB available (3464K code, 394K data, 124K init)
Calibrating delay loop... 397.31 BogoMIPS (lpj=1986560)
Security Framework v1.0.0 initialized
SELinux:  Initializing.
SELinux:  Starting in permissive mode
selinux_register_security:  Registering secondary module capability
Capability LSM initialized as secondary
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
NET: Registered protocol family 16
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
NET: Registered protocol family 2
Time: pxa_timer clocksource has been installed.
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 2048 (order: 2, 16384 bytes)
TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 2048 bind 2048)
TCP reno registered
checking if image is initramfs...it isn't (no cpio magic); looks like an initrd
Freeing initrd memory: 5120K
NetWinder Floating Point Emulator V0.97 (double precision)
audit: initializing netlink socket (disabled)
audit(7.339:1): initialized
yaffs Mar 10 2009 16:22:28 Installing.
io scheduler noop registered
io scheduler anticipatory registered
io scheduler deadline registered
io scheduler cfq registered (default)
pxa2xx-fb: probe of pxa2xx-fb failed with error -12
pxa2xx-uart.0: ttyPXA0 at MMIO 0x40100000 (irq = 15) is a FFUART
pxa2xx-uart.1: ttyPXA1 at MMIO 0x40200000 (irq = 14) is a BTUART
pxa2xx-uart.2: ttyPXA2 at MMIO 0x40700000 (irq = 13) is a STUART
pxa2xx-uart.3: ttyPXA3 at MMIO 0x41600000 (irq = 0) is a HWUART
RAMDISK driver initialized: 16 RAM disks of 12288K size 1024 blocksize
loop: loaded (max 8 devices)
PP_addr at f1000300[a]: 0x3136
eth0: cs8900 rev K found at 0xf1000300 [Cirrus EEPROM]
cs89x0 media RJ-45, IRQ 44, programmed I/O, MAC 00:fa:11:a3:23:05
NAND device: Manufacturer ID:0xec, Chip ID:0x76 (Samsung NAND 64MiB 3,3V 8-bit)
Scanning device for bad blocks
Bad eraseblock 1024 at 0x01000000
Creating 3 MTD partitions on "NAND 64MiB 3,3V 8-bit":
0x00000000-0x00100000 : "falinux boot/config/logo partition"
0x00100000-0x00900000 : "falinux kernel/ramdisk partition"
0x00900000-0x04000000 : "falinux yaffs partition"
usbmon: debugfs is not available
sl811: driver sl811-hcd, 19 May 2005
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
usbcore: registered new interface driver usbhid
drivers/usb/input/hid-core.c: v2.6:USB HID core driver
usbcore: registered new interface driver usbserial
drivers/usb/serial/usb-serial.c: USB Serial support registered for generic
usbcore: registered new interface driver usbserial_generic
drivers/usb/serial/usb-serial.c: USB Serial Driver core
drivers/usb/serial/usb-serial.c: USB Serial support registered for FTDI USB Sere
usbcore: registered new interface driver ftdi_sio
drivers/usb/serial/ftdi_sio.c: v1.4.3:USB FTDI Serial Converters Driver
mice: PS/2 mouse device common for all mice
i2c /dev entries driver
I2C: i2c-0: PXA I2C adapter
Advanced Linux Sound Architecture Driver Version 1.0.14rc3.
ALSA device list:
  No soundcards found.
TCP cubic registered
NET: Registered protocol family 1
NET: Registered protocol family 10
lo: Disabled Privacy Extensions
Mobile IPv6
IPv6 over IPv4 tunneling driver
sit0: Disabled Privacy Extensions
NET: Registered protocol family 17
XScale DSP coprocessor detected.
RAMDISK: Compressed image found at block 0
VFS: Mounted root (ext2 filesystem) readonly.
Freeing init memory: 124K
eth0: using full-duplex 10Base-T (RJ-45)
yaffs: dev is 32505858 name is "mtdblock2"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 31.2, "mtdblock2"
yaffs: auto selecting yaffs1
yaffs: block 448 is marked bad
block 449 is bad
eth0: no IPv6 routers present