[U-Boot-Users] How is the "ba 0xfff80000" located at 0xfffffffc ?

[腾飞龙]

     As in Embedded Planet EP405 board, ppc405GPr processor support
high boot only, when Power On or reset, the processor starts at
0xfffffffc and the code is executed from flash/rom. There is usually a
branch instruction(such as: ba target) in 0xfffffffc so that it can
jump to the target. For example, if i set TEXT_BASE=0xfff80000 in
u-boot,it means the instruction "ba 0xfff80000" is in 0xfffffffc. My
questions are follow:
  1 where can i find the branch instruction "ba 0xfff80000" in
u-boot-1.1.3 code? it seems it is not in start.s
  2 As we know, before u-boot is written to flash the first time,
there is nothing in flash. when we write u-boot in flash from addr
0xfff80000, how is the branch instruction written to addr 0xfffffffc
which is not neigbour to u-boot code body?
  Thank you and best wishes!