Investigating PE format (EXE and DLL)

[Charles Pegge]

Thanks for testing Petr.

The next step is to drop some of the current Asm examples into this framework and run them as standalones. To do this they must not have any run-time dependencies on Oxygen or thinBasic - so the small kernel of procedures like bind and copy0 have to be carried in the EXE file itself. Fortunately they are only a few hundred bytes. - I am rewriting these in Asm, then they can be incorporated into the framework for every EXE and DLL compiled.

[Charles Pegge]

Oxygen Update:

http://community.thinbasic.com/index.php?topic=1845

Yet another small fix but now we have demo code producing MessageBox, HelloWin and Opengl 4 Port viewer.

Despite their minuscule size, the executables are actually a bit bloated - with an un-needed export section.

Below are the thinBasic PE scripts and the demo EXEs ready compiled. Only thinBasic with the latest Oxygen was required to produce these. No headers, linkers or any other dependencies.

[kryton9]

Charles thanks for the demos all in one. Makes it easy for guys that have a hard time with this stuff, like me.
9KB for cool opengl Demo is neat, I like how you said it is still bloated

[Charles Pegge]

Well they are bloated by 512 bytes with the exports section, and I have not attempted any tricks like combining sections or using UBX compression.

Once the EXE is loaded into memory the minimum section size is 4K which means that these demos inflate to around 20k. But of course Opengl demands major resources so the overall memory size ends up around 8 Megs! (Just to put things in perspective.)

The next step is to write a thinBasic Module - so the exports section will be utilised. - 512 bytes will accommodate about 20 to 25 DLL function names.

[Petr Schreiber]

Hi Charles,

HellowWin in 3,584 bytes is really nice!


Petr

[ErosOlmi]

Charles,

I'm following your job here behind the curtains in a very silent way. I'm really fascinated about the possibilities I can just "smell" at the moment.
To be honest, my knowledge of the matter let me understand just 25%-30% of what you have done so far but I try to read again and again your scripts. At every read I can get a little more.

So, for the moment, thanks a lot for your job.
Eros

[zlatkoAB]

Excelent job Charles

[Charles Pegge]

Thanks. Working on these longer programs and a thinBasic module DK gives me ample opportunity to sample my own porridge - ande detect any lumpy bits, (before any one else does! ) - also preparing the ground for higher level syntax.

I've thought of calling my current piece: ThinBasic Oxygen Module Development Kit: TOMDK There's Tom & Dick but I couldn't think of a Harry

[Petr Schreiber]

Nice name ,

Charles, what is the purpose of TimeDateDecode in HelloWin creation?


Petr

[Charles Pegge]

Hi Petr,

The DateTime stamp is a 32 bit value representing the time in seconds since 1 Jan 1970. My algorithm disagrees with this (compared with a GNU compiled EXE) by exactly 1 hour for some reason so I correct this with a fudge factor. And I dont know what PB uses - it may be an arbitrary value.

Neither the TimeDate stamp nor the header checksum are operationally required. Though MS kernel DLLs require a header checksum

I am making good headway with TOMDK, I did not appreciate that Having a LIBMAIN is mandatory, even though it is not present in the exprt functions table. It is the main entry point of the module and is called when the module is loaded, and again just before the module is unloaded by the OS.