I am trying to debug bootloader with gdb in QEMU. I run QEMU command like this

./qemu-system-mips64 -s -S -m 1024 -M  octeon  -bios u-boot-octeon_ebh5610.bin  -kernel vmlinux.64 -append 'coremask=001 mem=0 root=/dev/sda2'

and then connect gdb using

mips64-octeon-linux-gnu-gdb u-boot-octeon_ebh5610
target remote localhost:1234

when i try to step into bootloader code, it continues execution without breaking. This totally skip the bootloader code which i want to examine step by step as it execute.
Can anyone suggest, what do i need to do to resolve this issue.
Thank You 
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Maryyam Muhammad Din
Al-Khawarizmi Institute of Computer Science
UET Lahore