[SeaBIOS] How to build seabios(coreboot style) with manually specified entry_elf() address ?

[Tang Rong]

Hi Matt, we chated about kexec booting chromeos for Acer C710 on IRC,
thanks a lot for your help.

I digged to into depthcharge code, and found they did quite a lot of
work, including patching the SMBIOS for fwid, redirecting ehci to
xhci, etc. However, SeaBios on RW_LEGACY can not enjoy these work as
legacy mode got started very early. In addition, flash
seabios/tianocore on ssd (pretending to be linux kernel) would be much
safer option.