Interesting discovery about the AtomBIOS files at " g505s-atombios " repository - https://github.com/g505s-opensource-researcher/g505s-atombios :
While there was the same "clean" proprietary UEFI image flashed both to "G505S with HD 8570M" and to "G505S with R5 M230" before the AtomBIOS extraction, their AtomBIOSes for _ integrated HD 8650G _ turned out as slightly different! (see sha256)
So I made their full disassembly with this AtomDis tool - https://cgit.freedesktop.org/~mhopf/AtomDis/ , and compared, diff results here - https://pastebin.com/eewzswnD . As you could see from these diff results, for some reason "G505S R5 version" sets a slightly higher voltages for its' integrated GPU :
compared to "G505S HD version" it is 1.8% - 3.2% higher if these 0x3e / 0x40 / 0x6e / 0x70 values are linear and 0x0 = 0 volts. (usNBP0Voltage / usNBP1Voltage / usVoltageID )
What do you think: would it be okay to use the integrated VGA BIOS obtained from "G505S R5 version" for "G505S HD version" ? This voltage difference seems small enough and the integrated GPU is the same part after all ---> I think that it should be fine.