Ali 
Hi, I am getting this error: Unable to handle kernel NULL pointer dereference at virtual address 00000001 pgd = c7030000 [00000001] *pgd=57bdb031, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] Modules linked in: zd1211rw rt73usb rt2x00usb rt2x00lib mac80211 CPU: 0 Not tainted (2.6.28.8-EmbedSky #4) PC is at kmem_cache_alloc+0x34/0x8c LR is at call_usermodehelper_setup+0x30/0x84 pc : [<c0093ce0>] lr : [<c005a7e0>] psr: 20000093 sp : c7bbdd68 ip : c7bbdd90 fp : c7bbdd8c r10: 00000000 r9 : c03e047c r8 : c04aee78 r7 : 00000040 r6 : 000080d0 r5 : 60000013 r4 : 00000001 r3 : 00000000 r2 : c7b8a000 r1 : 000080d0 r0 : c043e378 Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user Control: 00c5387d Table: 57030008 DAC: 00000015 Process rasa (pid: 595, stack limit = 0xc7bbc260) Stack: (0xc7bbdd68 to 0xc7bbe000) dd60: c78a7e40 c04aee78 c0455af8 c7bbddcc c7b8a000 c78a7e40 dd80: c7bbddac c7bbdd90 c005a7e0 c0093cb8 00000010 00000004 00000000 c78a7e40 dda0: c7bbde04 c7bbddb0 c0158b8c c005a7bc 000000d0 00000001 00000000 c7afb7e0 ddc0: c7b8a000 c03f6c88 c00d9240 c0455af8 c03e047c 00000000 00000000 00000000 dde0: c703c400 c703c48c c04b5548 c703c468 00000000 c0455c00 c7bbde14 c7bbde08 de00: c0158c00 c0158870 c7bbde5c c7bbde18 c01929ac c0158bf8 00000000 00000000 de20: c7bbde44 c7bbde30 c0157d88 c0158cc8 c703c400 c703c400 c0455c00 00000000 de40: 00000000 c04af5a0 c7018418 c7bbdf70 c7bbde74 c7bbde60 c0192ab4 c019258c de60: c703c400 c0455c00 c7bbde9c c7bbde78 c0192b44 c0192aa4 c7bbdecc 000000c8 de80: 00000001 c04af5a0 c0459d04 c7018418 c7bbdec4 c7bbdea0 c0192b88 c0192ac4 dea0: c03f701c c7bbdecc c015de60 c7bbdecc 00000000 00000000 c7bbdeec c7bbdec8 dec0: c0164e6c c0192b6c c03f701c 000000c8 00000000 00000003 c7018400 c783a248 dee0: c7bbdf0c c7bbdef0 c0164f34 c0164d98 40023000 000000c8 00000003 c7811510 df00: c7bbdf1c c7bbdf10 c01950cc c0164ef4 c7bbdf4c c7bbdf20 c00d750c c01950ac df20: c7bbdf70 c7bb4900 40023000 c7bbdf70 40023000 00000003 c7bbc000 00000000 df40: c7bbdf6c c7bbdf50 c009797c c00d740c 00000000 00000000 c7bb4900 40023000 df60: c7bbdfa4 c7bbdf70 c0097a8c c00978d8 00000000 00000000 528d426c 00000001 df80: 00001000 00000003 40023000 000c0ff0 00000004 c002bf88 00000000 c7bbdfa8 dfa0: c002bde0 c0097a54 00000003 40023000 00000016 40023000 00000003 00000000 dfc0: 00000003 40023000 000c0ff0 00000004 00000003 00000003 bec3056c 0005aa88 dfe0: 00000000 bec303e8 40e76524 40e76534 60000010 00000016 6361203a 6c617574 Backtrace: [<c0093cac>] (kmem_cache_alloc+0x0/0x8c) from [<c005a7e0>] (call_usermodehelper_setup+0x30/0x84) r7:c78a7e40 r6:c7b8a000 r5:c7bbddcc r4:c0455af8 [<c005a7b0>] (call_usermodehelper_setup+0x0/0x84) from [<c0158b8c>] (kobject_uevent_env+0x328/0x388) r7:c78a7e40 r6:00000000 r5:00000004 r4:00000010 [<c0158864>] (kobject_uevent_env+0x0/0x388) from [<c0158c00>] (kobject_uevent+0x14/0x18) [<c0158bec>] (kobject_uevent+0x0/0x18) from [<c01929ac>] (device_add+0x42c/0x518) [<c0192580>] (device_add+0x0/0x518) from [<c0192ab4>] (device_register+0x1c/0x20) [<c0192a98>] (device_register+0x0/0x20) from [<c0192b44>] (device_create_vargs+0x8c/0xa8) r5:c0455c00 r4:c703c400 [<c0192ab8>] (device_create_vargs+0x0/0xa8) from [<c0192b88>] (device_create+0x28/0x30) r9:c7018418 r8:c0459d04 r7:c04af5a0 r6:00000001 r5:000000c8 r4:c7bbdecc [<c0192b60>] (device_create+0x0/0x30) from [<c0164e6c>] (gpio_export+0xe0/0x15c) r4:00000000 [<c0164d8c>] (gpio_export+0x0/0x15c) from [<c0164f34>] (export_store+0x4c/0xa0) r7:c783a248 r6:c7018400 r5:00000003 r4:00000000 [<c0164ee8>] (export_store+0x0/0xa0) from [<c01950cc>] (class_attr_store+0x2c/0x30) r5:c7811510 r4:00000003 [<c01950a0>] (class_attr_store+0x0/0x30) from [<c00d750c>] (sysfs_write_file+0x10c/0x190) [<c00d7400>] (sysfs_write_file+0x0/0x190) from [<c009797c>] (vfs_write+0xb0/0xe4) [<c00978cc>] (vfs_write+0x0/0xe4) from [<c0097a8c>] (sys_write+0x44/0x74) r7:40023000 r6:c7bb4900 r5:00000000 r4:00000000 [<c0097a48>] (sys_write+0x0/0x74) from [<c002bde0>] (ret_fast_syscall+0x0/0x2c) r8:c002bf88 r7:00000004 r6:000c0ff0 r5:40023000 r4:00000003 Code: e5907090 e3540000 0a000010 e590308c (e7942103) ---[ end trace e4489192415e06ed ]--- Please help me.