Hi!
I have a 32-bit .so binary-only library and I have to generate 64-bit program that uses it. Is there a way to wrap or convert it, so it can be used with 64-bit program?
+5
A:
No. You can't directly link to 32bit code inside of a 64bit program.
The best option is to compile a 32bit (standalone) program that can run on your 64bit platform (using ia32), and then use a form of inter-process communication to communicate to it from your 64bit program.
Reed Copsey
2009-12-22 01:30:32
@Reed: Then how did Win95 manage the transition from 32bit code calling 16bit a la 'thunking' ? Was that at the assembler level to change around the stack pointer and registers?
tommieb75
2009-12-22 01:41:05
The OS handled this explicitly, but there is nothing that allows this in Linux or modern 64bit Windows operating systems, so you have to use a workaround like I posted.
Reed Copsey
2009-12-22 01:42:22
@Reed: Thanks for answering my question. :)
tommieb75
2009-12-22 01:45:07
@Reed: what IPC mechanism would you recommend? I think that shared memory should be reasonable faster then e.g. pipes or Unix Doman Sockets.
2009-12-24 08:36:43
+1
A:
It is possible, but not without some serious magic behind the scenes and you will not like the answer. Either emulate a 32 bit CPU (no I am not kidding) or switch the main process back to 32 bit. Emulating may be slow though.
This is a proof of concept of the technique.
Then keep a table of every memory access to and from the 32 bit library and keep them in sync. It is very hard to get to a theoretical completeness, but something workable should be pretty easy, but very tedious.
In most cases, I believe two processes and then IPC between the two may actually be easiest, as suggested othwerwise.
Amigable Clark Kant
2009-12-22 01:51:32
+2
A:
For an example of using IPC to run 32-bit plugins from 64-bit code, look at the open source NSPluginWrapper.
Zan Lynx
2009-12-22 01:58:15