SiPy keeps rebooting

[Alok K Mishra]

after firmware update using Pycom Firmware Update utility my SiPy keeps rebooting with following stack trace

Rebooting...
ets Jun 8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x12 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff8028,len:8
load:0x3fff8030,len:1688
load:0x4009fa00,len:0
load:0x4009fa00,len:14476
entry 0x400a05ac
Guru Meditation Error: Core 0 panic'ed (LoadProhibited)
. Exception was unhandled.
Register dump:
PC : 0x4011a557 PS : 0x00060830 A0 : 0x801113f0 A1 : 0x3ffbd6a0
A2 : 0xffffffff A3 : 0x3ffbd700 A4 : 0xb33fffff A5 : 0xffffffff
A6 : 0x000000aa A7 : 0x3ffd33d0 A8 : 0x800d2577 A9 : 0x3ffd33d0
A10 : 0x00000000 A11 : 0x00000000 A12 : 0x00000000 A13 : 0x0012df3e
A14 : 0x0000002a A15 : 0x3ffd33b0 SAR : 0x0000001f EXCCAUSE: 0x0000001c
EXCVADDR: 0xffffffff LBEG : 0x4009a664 LEND : 0x4009a692 LCOUNT : 0xffffffff

Backtrace: 0x4011a557:0x3ffbd6a0 0x401113ed:0x3ffbd700 0x4011e1fd:0x3ffbd770 0x4011e4ba:0x3ffbd790 0x40129292:0x3ffbd7b0

what I need to do to get it back to normal boot