The endianness of the MicroBlaze processor is set by parameter C_ENDIANNESS in 8.00 or greater.
However, it should be not edited in most circumstances by the user. The C_ENDIANNESS parameter is always automatically set to little endian when using AXI4, and to big endian when using PLB.
If it is assigned in MHS manually, platgen gives the following warning:
"WARNING:EDK - IPNAME: microblaze, INSTANCE: microblaze_0 - PARAMETER:
C_ENDIANNESS has value 0 specified in MHS, but tcl is overriding the value to 1"