20 Apr
2025
20 Apr
'25
8:42 p.m.
On Sun Apr 20 20:42:19 2025 +0000, Alexandre Julliard wrote:
Are there actual apps that depend on these things?
Yes, this is known technique described in the Andrew Schulman book: Unauthorized Windows 95. kernel32.dll VxDCall function allows to call DPMI functions directly from native 32-bit applications. Code samples of VxDCall usage are part of the book. The DPMI physical address mapping function (as described in the commit message) is used for example by SysToolsLib or by WinIO or by lspci. All of them are checking for carry flag to figure out if the DPMI function call failed or not.