What is the difference of target ?

What is the difference of target ?

[Woo-Seung Yeo]

  Hi..
  I'm looking for the difference between target
  powerpc-eabi and powerpc-linux for a while.
  But I can't find. gcc mailing list is too big..
  Let me know.....

  Woo-Seung Yeo.
  wsyeo@dmc.htc.hanwha.co.kr

Re: What is the difference of target ?

[Jean-Pierre Radley]

Woo-Seung Yeo propounded (on Tue, Jan 25, 2000 at 11:34:28AM +0900):
| 
|   I'm looking for the difference between target
|   powerpc-eabi and powerpc-linux for a while.
|   But I can't find. gcc mailing list is too big..
|   Let me know.....

Some place, list, or resource is big, so you think that someone else
should search there instead of you?

Why?

-- 
JP

Re: What is the difference of target ?

[Woo-Seung Yeo]

Jean-Pierre Radley wrote:

> Woo-Seung Yeo propounded (on Tue, Jan 25, 2000 at 11:34:28AM +0900):
> |
> |   I'm looking for the difference between target
> |   powerpc-eabi and powerpc-linux for a while.
> |   But I can't find. gcc mailing list is too big..
> |   Let me know.....
>
> Some place, list, or resource is big, so you think that someone else
> should search there instead of you?
>
> Why?
>
> --
> JP

  I'm so sorry to all maintainers of gcc.
  I'm newcomer to this mailling list and so poor in english.
  I'm in korea and connection to this site is too slow.
  So I want to get something even a hint....
  Sorry...

Re: What is the difference of target ?

[Jean-Pierre Radley]

Woo-Seung Yeo propounded (on Tue, Jan 25, 2000 at 12:36:49PM +0900):
| 
| Jean-Pierre Radley wrote:
| 
| > Woo-Seung Yeo propounded (on Tue, Jan 25, 2000 at 11:34:28AM +0900):
| > |
| > |   I'm looking for the difference between target
| > |   powerpc-eabi and powerpc-linux for a while.
| > |   But I can't find. gcc mailing list is too big..
| > |   Let me know.....
| >
| > Some place, list, or resource is big, so you think that someone else
| > should search there instead of you?
| >
| > Why?
| 
|   I'm so sorry to all maintainers of gcc.

No need to apologize for that.

|   I'm newcomer to this mailling list and so poor in english.

No need to apologize for that either.

|   I'm in korea and connection to this site is too slow.

Ah, then you should have said that in your first message: "I have a slow
connection, and it takes too long for me to get the answer to my
question, which is 'what is the difference... etc.?'"

|   So I want to get something even a hint....
|   Sorry...

No problem.

-- 
JP

Re: What is the difference of target ?

[David Edelsohn]

	Linux/PPC (powerpc-linux) originally was developed on embedded
systems, so the eABI definitions initially were used.  Linux/PPC has since
switched to the less strict SVR4 ABI definitions.

	The eABI is related to SVR4 ABI for PowerPC with a few
modifications targeted at the embedded community, such as stricter
alignment requirements and a register dedicated to a small data area.
powerpc-linux is powerpc-sysv with a few Linux definitions which do not
affect the actual calling conventions.  Motorola has copies of the SVR4
and eABI documents at their website, but I do not remember the URLs
offhand.

David
===============================================================================
David Edelsohn                                      T.J. Watson Research Center
dje@watson.ibm.com                                  P.O. Box 218
+1 914 945 4364 (TL 862)                            Yorktown Heights, NY 10598

Re: What is the difference of target ?

[Michael Meissner]

On Mon, Jan 24, 2000 at 10:52:06PM -0500, David Edelsohn wrote:
> 	Linux/PPC (powerpc-linux) originally was developed on embedded
> systems, so the eABI definitions initially were used.  Linux/PPC has since
> switched to the less strict SVR4 ABI definitions.
> 
> 	The eABI is related to SVR4 ABI for PowerPC with a few
> modifications targeted at the embedded community, such as stricter
> alignment requirements and a register dedicated to a small data area.
> powerpc-linux is powerpc-sysv with a few Linux definitions which do not
> affect the actual calling conventions.  Motorola has copies of the SVR4
> and eABI documents at their website, but I do not remember the URLs
> offhand.

Actually regarding the alignment issues, it is the other way around.  eABI
wants 8 byte stack alignment, ABI (aka linux) wants 16 byte alignment.  ABI
reserves 1 small data register (r13) and eABI reserve 2 (r2 and r13), though in
both cases you need to use the -msdata switch to enable use of the small data
area.  Both are big endian (though you can configure for powerpcle-eabi to
default to little endian, linux must be big endian).  The extra files linked in
by the compiler are different between the two, and eABI calls a function __eabi
to do the initialization in the function __main.  eABI defines a bunch of
relocations that ABI doesn't, and doesn't have to implement the system V shared
library relocations.  eABI supports -mrelocatable which linux doesn't
(-mrelocatable allows you to take a program and drop it anywhere in memory, as
long as the data and text regions are the same distance apart -- while Linux
uses a runtime loader for shared libraries).  Another place that has the specs
is:

	http://www.esofta.com/softspecs.html

-- 
Michael Meissner, Red Hat, Inc.
PMB 198, 174 Littleton Road #3, Westford, Massachusetts 01886
Work:	  meissner@redhat.com		phone: 978-486-9304 fax: 978-692-4482
Non-work: meissner@spectacle-pond.org

Re: What is the difference of target ?

[Gabriel Paubert]

On Tue, 25 Jan 2000, Michael Meissner wrote:

> Actually regarding the alignment issues, it is the other way around.  eABI
> wants 8 byte stack alignment, ABI (aka linux) wants 16 byte alignment.  ABI
> reserves 1 small data register (r13) and eABI reserve 2 (r2 and r13), though in
> both cases you need to use the -msdata switch to enable use of the small data
> area.  Both are big endian (though you can configure for powerpcle-eabi to
> default to little endian, linux must be big endian).  The extra files linked in
> by the compiler are different between the two, and eABI calls a function __eabi
> to do the initialization in the function __main.  eABI defines a bunch of
> relocations that ABI doesn't, and doesn't have to implement the system V shared
> library relocations.  eABI supports -mrelocatable which linux doesn't
> (-mrelocatable allows you to take a program and drop it anywhere in memory, as
> long as the data and text regions are the same distance apart -- while Linux
> uses a runtime loader for shared libraries).  


I always wondered why -mrelocatable was incompatible with -msdata, since
-mrelocatable uses r30 for relocs and never use r2 nor r13.

And when I tried to force a frequently accessed global structure to be
pointed to by r2 (this made many functions smaller), the compiler (2.95.2
in this case) aborts with the the following message:

bootldr.h:153: warning: register used for two global register variables
misc.c: In function `dump_context':
misc.c:127: Internal compiler error:
misc.c:127: GOT/TOC register marker not removed:
(set (reg:SI 5 r5)
    (mem/s:SI (plus:SI (reg/v:SI 2 r2)
            (const_int 36 [0x24])) 0))
cpp: output pipe has been closed

Earlier compilers had a much more cryptic error message AFAIR. But it
works with r13 BTW.

	Gabriel. 

What is the difference of target?

[Woo-Seung Yeo]

  Hi..
  I'm looking for the difference between target
  powerpc-eabi and powerpc-linux for a while.
  But I can't find. gcc mailing list is too big..
  Let me know.....

  Woo-Seung Yeo.
  wsyeo@dmc.htc.hanwha.co.kr