> mov d1,5
> mov errno(a5), d1
> Now, when you link this library to the aplllication A, errno offset from the
> beginnig of data segment will be let's say 0x100
> and when you link the library to application B the offset could be 0x200...
> In any case the actual contents of the libaray .text
> segment is different, hence you can't do code sharing.....
The trick here is to collect the library global data and bss into a seperate
section _after_ the executable's .bss and .data. The library then uses a
trampoline on the stub to update %a5 to point at the start of it's own data
when it's called. The executable just uses %a5 normally.
Now I we just need to ask binutils nicely to collect these blocks of
.data and .bss... That should be fairly easy.
> ----- Original Message -----
> From: Erwin Authried <firstname.lastname@example.org>
> To: Vadim Lebedev <email@example.com>; <firstname.lastname@example.org>
> Cc: <email@example.com>
> Sent: Thursday, January 06, 2000 12:50 AM
> Subject: Re: [UCLINUX] Fw: 32-bit PIC patches for the uCsimm !
> > Hello Vadim,
> > maybe I'm missing something obvious, but I don't see any problem right
> > Maybe it's simply to late for thinking ;-)
> > Currently, the text segment of the library of the library is linked with
> > application. If the complete library is put into a free space with a
> > adress, and the link script is modified to take care of that, the library
> > routines
> > can be executed there because all applications share the same adress
> > and all the call offsets may be 32 bit with the patch. Of course, all
> > applications
> > have to be linked with the same, complete library.
> > The data + bss segment is handled like before. That shouldn't have to do
> > anything with the kernel, there no such stuff like usage-count or
> > similar to handle. Please let me know if I'm missing something important.
> > Regards,
> > Erwin
> > Vadim Lebedev wrote:
> > > This shared library stuff is more complicated than you think,
> > > fo example what you're going to do with shared library static data?
> > > Another point: the kernel should be modified to handle correctly
> > > libraries....
> > >
> > > Best regards
> > > Vadim
> > >
> > > ----- Original Message -----
> > > From: Erwin Authried <firstname.lastname@example.org>
> > > To: <email@example.com>
> > > Cc: <firstname.lastname@example.org>
> > > Sent: Wednesday, January 05, 2000 10:49 PM
> > > Subject: [UCLINUX] Fw: 32-bit PIC patches for the uCsimm !
> > >
> > > > I have just recognized that it is not necessary to recompile
> > > > the whole library, sorry. There are just a few library-internal calls
> > > > cannot be relocated because the call is made between the start
> > > > of the text segment to the end of the text segment where the libraries
> > > > are located. When those few calls are fixed, the rest of the library
> > > use the
> > > > faster 16-bit relocation.
> > > >
> > > > Another idea: When all the libraries are linked to some fixed
> > > > location, they could now be shared between all applications, without
> > > > the overhead of having the same library attached to each
> > > > application.
> > > >
> > > > -Erwin
> > > >
> This message resent by the email@example.com list server http://www.uClinux.com/
This message resent by the firstname.lastname@example.org list server http://www.uClinux.com/
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