UClinux Shared Library - Revision history

Cschalle: Add category

2011-10-28T08:28:32Z

Add category

Jsujjava: Add m68knommu information

2011-04-26T15:22:50Z

Add m68knommu information

Vapier: reorganize page to put relevant stuff at top and push down "noise", and update with real/current information

2009-04-12T08:47:48Z

reorganize page to put relevant stuff at top and push down "noise", and update with real/current information

Prpplague at 21:21, 24 September 2007

2007-09-24T21:21:09Z

Prpplague at 21:20, 24 September 2007

2007-09-24T21:20:30Z

RBot: Bot (Edward's framework)

2007-03-06T03:46:13Z

Bot (Edward's framework)

New page

== Using Shared Library on uClinux ==

Shared Library support is important for various cases. Especially if you are using uClinux with LGPL library, if there is no Shared Library support with your system, that means you get hit by GPL/LGPL license issue because LGPL library can only be linked by Shared Library (dynamic link) or the application source code needs to be provided to the customer (if the customer wants).

There were various efforts for supporting Shared Library on uClinux so far. This page describes those efforts with corresponding information.

=== [[Ridge Run]] and [[Snap Gear]] announcement ===

[[Ridge Run]] and [[Snap Gear]] has announced that they implemented Shared Library on uClinux long time ago.

For more information: http://linuxdevices.com/articles/AT3186625227.html

[[Ridge Run]] approach uses ELF format file and [[Snap Gear]] approach uses flat file format.

Flat File Format method is supported only for m68knommu targets (older 2.4 & all 2.6)

[[Ridge Run]] stopped their business at 2002 but they are now back. Their method is described at: http://www.ridgerun.com/XflatPages/CadenuxXFLATSharedLibraries

When they stopped, some of their code was released under GPL because they had something to do with Texas Instruments. [[Monta Vista]] may have some more information on this but currently none has seen [[Ridge Run]]'s Shared Library implementation code at the open source region.

But after they are back to their business, the new [[Ridge Run]] has set up xflat as an open source project at http://www.xflat.org

=== Kernel 2.4.x status ===

Shared libraries under uClinux mini-HOWTO: http://www.ucdot.org/article.pl?sid=03/11/25/1126257&mode=thread

But ARM does not support it, see at bottom page: http://www.ucdot.org/article.pl?sid=03/07/24/1333235&mode=thread

Another interesting topic: http://www.ucdot.org/article.pl?sid=03/10/21/2153216&mode=thread

=== Kernel 2.6.x status ===

At the moment there are two options for shared support, there's a shared flat format (grep the kernel for CONFIG_BINFMT_SHARED_FLAT), and then there's support for FDPIC ELF (currently only implemented for FR-V).
Look at fs/Kconfig.binfmt in a recent 2.6 kernel to get a better idea of your options.

=== Credit ===

This rough page was originally created by [[Shawn Kwon]] but most of the information were collected from comments of various people including Paul Mundt, Steve Bunch, Tim Bird, Greg Ungerer, Todd Fischer, Alan Carvalho de Assis at celinux-dev mailing list. All the credit should go to them.

← Older revision		Revision as of 08:28, 28 October 2011
Line 71:		Line 71:

	This rough page was originally created by Shawn Kwon but most of the information were collected from comments of various people including Paul Mundt, Steve Bunch, Tim Bird, Greg Ungerer, Todd Fischer, Alan Carvalho de Assis at celinux-dev mailing list. All the credit should go to them.		This rough page was originally created by Shawn Kwon but most of the information were collected from comments of various people including Paul Mundt, Steve Bunch, Tim Bird, Greg Ungerer, Todd Fischer, Alan Carvalho de Assis at celinux-dev mailing list. All the credit should go to them.
		+
		+	[[Category:UCLinux]]

@@ Line 57: / Line 57: @@
 But after they are back to their business, the new Ridge Run has set up xflat as an open source project at http://www.xflat.org
 === Credit ===
 This rough page was originally created by Shawn Kwon but most of the information were collected from comments of various people including Paul Mundt, Steve Bunch, Tim Bird, Greg Ungerer, Todd Fischer, Alan Carvalho de Assis at celinux-dev mailing list. All the credit should go to them.

@@ Line 5: / Line 5: @@
 There were various efforts for supporting Shared Library on uClinux so far. This page describes those efforts with corresponding information.
-=== Ridge Run and SnapGear announcement ===
+=== Shared FLAT ===
-[http://www.ridgerun.com/ Ridge Run] and [http://www.snapgear.com SnapGear] has announced that they implemented Shared Library on uClinux long time ago.
+The Shared FLAT format follows the FLAT format in terms of being an extremely stripped down and lightweight format:
-For more information: http://linuxdevices.com/articles/AT3186625227.html
+However, these things come by sacrificing flexibility:
-Ridge Run approach uses ELF format file and Snap Gear approach uses flat file format.
+=== FDPIC ELF ===
-Flat File Format method is supported only for m68knommu targets (older 2.4 & all 2.6)
+The FDPIC ELF format brings all the amenities of the standard ELF format as seen on Desktop Linux systems.  The trade offs are mostly obvious:
-Ridge Run stopped their business at 2002 but they are now back. Their method is described at: http://www.ridgerun.com/XflatPages/CadenuxXFLATSharedLibraries
+=== Kernel 2.6.x status ===
-When they stopped, some of their code was released under GPL because they had something to do with Texas Instruments. [[Monta Vista]] may have some more information on this but currently none has seen Ridge Run's Shared Library implementation code at the open source region.
+There are two options with recent kernels:
-But after they are back to their business, the new Ridge Run has set up xflat as an open source project at http://www.xflat.org
+Most no-mmu Linux architectures support Shared FLAT, but the FDPIC ELF format is gathering ports.  Support will greatly depend on the exact kernel version you are using, so check the ''fs/Kconfig.binfmt'' file if you are unsure.
 === Kernel 2.4.x status ===
@@ Line 29: / Line 42: @@
 Another interesting topic: http://www.ucdot.org/article.pl?sid=03/10/21/2153216&mode=thread
-=== Kernel 2.6.x status ===
+=== Ridge Run and SnapGear announcement ===
-At the moment there are two options for shared support, there's a shared flat format (grep the kernel for CONFIG_BINFMT_SHARED_FLAT), and then there's support for FDPIC ELF (currently only implemented for FR-V).
+[http://www.ridgerun.com/ Ridge Run] and [http://www.snapgear.com SnapGear] has announced that they implemented Shared Library on uClinux long time ago.
-Look at fs/Kconfig.binfmt in a recent 2.6 kernel to get a better idea of your options.
 === Credit ===
 This rough page was originally created by Shawn Kwon but most of the information were collected from comments of various people including Paul Mundt, Steve Bunch, Tim Bird, Greg Ungerer, Todd Fischer, Alan Carvalho de Assis at celinux-dev mailing list. All the credit should go to them.

← Older revision		Revision as of 21:21, 24 September 2007
Line 36:		Line 36:
	=== Credit ===		=== Credit ===

−	This rough page was originally created by [[Shawn Kwon]] but most of the information were collected from comments of various people including Paul Mundt, Steve Bunch, Tim Bird, Greg Ungerer, Todd Fischer, Alan Carvalho de Assis at celinux-dev mailing list. All the credit should go to them.	+	This rough page was originally created by Shawn Kwon but most of the information were collected from comments of various people including Paul Mundt, Steve Bunch, Tim Bird, Greg Ungerer, Todd Fischer, Alan Carvalho de Assis at celinux-dev mailing list. All the credit should go to them.