_Debug_Printf_Service

include vmm.inc

push    pArgs
push    pFormat
VMMCall _Debug_Printf_Service
add     esp, 8

(Windows 95 and later) Prints debug output. This is an asynchronous service. Uses the C calling convention.

pFormat
C-style "printf" format string.
pArgs
Address of the array of substitution arguments.

The %-escapes understood by _Debug_Printf_Service are the same ones supported by wdeb386. (_Debug_Printf_Service merely calls the debugger to display the string.)

The total size of the output cannot exceed 256 bytes.

pArgs is a pointer to the substitution arguments, rather than being the first substitution itself. This service would more accurately have been named _Debug_Vprintf_Service.

This service has no effect in the retail version of Windows. It is intended to be used with the debugging version.