Re: RFC ARM multi-arch and object format detection

[Richard Earnshaw <rearnsha@arm.com>]

Right, I've revised the patch slightly and committed it.

The main difference is that with a flash of inspiration last night as I 
was driving home from work, I realized that there is a simple way to 
support the multiple ABI variants and their corresponding tdep files 
without having to always link all of them into a single gdb session (you 
can do if you want, but it's not required).

The new patch adds a new arm-specific gdbarch registration function 
(arm_gdbarch_register_os_abi) to arm-tdep.c, using which the other arm 
tdep files can register their ability to handle that ABI variant.  ABI 
detection is still handled by the common code -- a design decision which I 
think is correct, but can be changed at a later date.

It is acceptable for a tdep file to register the ability to handle more 
than one abi variant, but it is not acceptable to have more than one tdep 
file trying to handle a variant.

2002-02-15  Richard Earnshaw  <rearnsha@arm.com>

	* arm-tdep.h (enum arm_abi): New enum.
	(struct gdbarch_tdep): New structure.
	(LOWEST_PC): Provide a default.
	(arm_gdbarch_register_os_abi): Declare new function.
	* arm-tdep.c (arm_abi_names): New array.
	(process_note_abi_tag_sections): New function.
	(get_elfosabi): New function.
	(arm_gdbarch_register_os_abi): New function.
	(arm_gdbarch_init): Try to determine the ABI of the inferior.  If
	support for that ABI has been built in, then call the appropriate
	configuration routine.  Use gdbarch_num_regs() to get the number
	of registers.
	(arm_dump_tdep): New function.
	(arm_init_abi_eabi_v1, arm_init_abi_eabi_v2, arm_init_abi_apcs): New
	place-holder functions.
	(_initialize_arm_tdep): Register them.
	* config/arm/tm-arm.h (LOWEST_PC): Delete.

	* armnbsd-tdep.c: New file.
	* Makefile.in (armnbsd-tdep.o): Add dependencies.
	* config/arm/nbsd.mt (TDEPFILES): Add it.
	* config/arm/tm-nbsd.h (LOWEST_PC): Delete.

	* armnbsd-nat.c: Include regcache.h.
	* Makefile.in (armnbsd-nat.o): Update dependency list.

	* arm-tdep.c (arm_get_next_pc): Use printf_filtered for error message.