Both keyboard and mouse are plugged I can boot linux with LinuxBIOS.
good.
Is there any board depedent part other than shadow memory control?
no.
For now, I just want to see screen output from VGABIOS or BOCHS BIOS.
hmm can you try warm boot? ie first boot with your classic pc bios, then warm boot into the linuxbios+adlo and all other stuff.
If you have ICE, you could try to see how far it goes. u could setup execution break point at 0x7C00 as it is used repeately during the boot.