Open-source way to set LAA bit on an executable

[Konstantin Kharlamov]

On Sat, 2021-01-30 at 16:14 +0300, Konstantin Kharlamov wrote:
> I'm in search for open-source way to modify a LAA bit (Large Address Aware) on
> PE executables. Background is that there are 32-bit games (such as the first
> "Mass Effect") that are limited to lower 2G of address space, and they're
> crashing on people upon using performance-enhancing WINE addons, like Gallium
> Nine or DXVK, due to slightly increased memory consumption. So, they need to
> have LAA bit set.¹
> 
> Currently, the way everyone recommends is `editbin.exe`,² but not only it is
> proprietary, it is also Windows-only. So I'd prefer to abstain of recommending
> it unless there's really no other way. I also tried reverse-engeneering
> framework radare, but long story short, it didn't work out.³

FTR, now I have a way to do it with radare (although it requires using raw offsets manually, but otherwise it works). Still curious though, how would one modify fields of what objdump calls "private headers" with objcopy.