Pavel Shtemenko published the article How to create own os2ldr (Russian language) (2008-03-17)
OS2LDR is much more than a loader for OS2KRNL. It also incorporates a library of about 50 call-back functions, known internally as "Dos Helper" functions, which the kernel uses both during and after initialization to talk to the PC hardware. This library, it seems, is the beginning of an attempt to insulate the core functions of the kernel-- task management, memory management, semaphore handling, and so on-- from the "bare metal" of the PC architecture-- the knowledge of which ports control which peripheral chips, how the BIOS data area is laid out, and the like. To those of you who have read the book on OS/2 for the PowerPC, this concept should start to sound familiar. Can you say "micro-kernel"?
Article Google English Translation.Source: eComStation.Ru