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2015-10-08xtensa: support call0 ABIMax Filippov
Most changes are mechanical replacement of 'retw' instruction with 'abi_ret' macro, defined to 'retw' or 'ret' according to ABI. Assembly code that makes calls is duplicated for call0 ABI with changed register numbers for parameters/return value and call instruction. 'entry' instructions are replaced with 'abi_entry' macro. More interesting changes: - non-leaf assembly functions (e.g. _dl_tlsdesc_dynamic, _dl_linux_resolve, SYSCALL_ERROR_HANDLER, PSEUDO) now need to preserve registers around intermediate calls they make, use temporary stack frame for that; - setjmp/longjmp only need to save and restore return address, stack pointer and callee-saved registers in the jmpbuf; - __clone and syscall functions had hardcoded offsets to parameter passed on stack, on call0 ABI they don't need stack frame, so the offset is different. Replace these offsets with FRAMESIZE macro. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2008-01-05Chris Zankel writes:Mike Frysinger
The following patches add support for the Xtensa processor architecture to uClibc. They are based on a recent SVN checkout (12/05/2007). The first patch (attached to this post) adds Xtensa support to various shared configuration and make files. The following patches then include the Xtensa specific files and directories. I welcome any feedback and would appreciate it if you could include the patches into the mainline tree. I am certainly committed to maintain the port. Bob Wilson was kind enough to review the patches. Some notes about the architecture: Xtensa is a configurable and extensible processor architecture developed by Tensilica. For more information, please visit: www.linux-xtensa.org.