Step 1:
so the first step is to disable the touch screen driver in the kernel source tree.
step 2:
--- USB support
[*] USB device filesystem
<*> USB Gadget Support --->
step 3:
cross compile the kernel,boot the new kernel and filesystem. go to compiled linux source tree and download g_file_storage.ko to mini2440.
step 4:
Creating a backing storage file
since the mini2440 has 64 MB flash, I allocated 10MB space for backup storage file. Creating a backing storage file
bash# dd bs=1M count=10 if=/dev/zero of=/root/backing_file
step 5:
Partitioning the backing storage
bash# fdisk /root/backing_file
Device contains neither a valid DOS partition table, nor Sun or SGI disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.
You must set heads sectors and cylinders.
You can do this from the extra functions menu.
Command (m for help):
Give the "x" (eXpert or eXtra) command:
Command (m for help): x
now select Heads, Sectors, and Cylinders
g_file_storage uses a sector size of 512 bytes, so 8 sectors/track will give us 4096 bytes
per track
Expert command (m for help): s
Number of sectors (1-63): 8
Warning: setting sector offset for DOS compatiblity
With 4 KB per track, 16 heads will give us a total of 64 KB per cylinder
Expert command (m for help): h
Number of heads (1-256): 16
Since we've got 64 KB per cylinder and 10 MB total, we need to use 320
cylinders.
Expert command (m for help): c
Number of cylinders (1-131071): 320
Now return to the normal menu (the "r" command):
Expert command (m for help): r
creating a primary partition
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-1024, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-1024, default 1024):
Using default value 1024
Since you want to use the gadget with a Windows host, you should change the
partition type (the "t" command) to FAT32 (code "b")
Command (m for help): t
Partition number (1-4): 1
Hex code (type L to list codes): b
Changed system type of partition 1 to b (Win95 FAT32)
Finally write out ("w") the partition table to the backing storage:
Command (m for help): w
The partition table has been altered!
Adding a filesystem
You use the losetup program to set up the loop
device driver with the proper offset:
# losetup -o 4096 /dev/loop0 /root/backing_file
and then you can mount it:
# mount -t vfat /dev/loop0 /mnt/loop
/dev/loop0 is mapped to the partition within the backing
storage. You can create a filesystem on it:
# mkdosfs /dev/loop0
now do "insmod g_file_storage file=/root/backing_file" on mini2440,then connect mini2440 to host PC.
the FAT32 partition with will be visible as storage device on Host system
