[U-Boot] access u-boot environment variables from kernel space

[Manukumar]

Dear All,

I have to implement the jtag and execute XSVF file through diagnostic
command from u-boot.
the layout of our board as below:
__________
|_Processor| -> FPGA -> CPLD----
    ^ 			       |
    |__________________________| 

I can able to get Device ID of both FPGA and CPLD
but iam not able to execute XSVF file.
when i debuged the code i found that it is expecting data 
from TDO line. but this is not happening.

My question is:
when i can able to get device id why can i execute the XSVF file 

NOTE:
The state is moving As below 

xsvfDoXREPEAT
xsvfDoXENDXR
xsvfDoXENDXR
xsvfDoXSTATE
xsvfDoXSTATE 
xsvfDoXRUNTEST
xsvfDoXSIR 
xsvfDoXSDRSIZE                                                                                                
xsvfDoXSDRSIZE
xsvfDoXTDOMASK
xsvfDoXSDRTDO

TAP State = DRUPDATE
   TAP State = RUNTEST/IDLE
 TDO Expected = 0xf4004093
 TDO Captured =
 TDO Mask     = 0x0fffffff
xsvfDoXSDRTDO iErrorCode
ERROR:  TDO mismatch
ERROR at or near XSVF command #10.See line #10 in the XSVF ASCII file.
Upgarde the Image and RESTART  !!!

Regards
Manukumar