From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Harris To: Subject: PC and PSR on 26-bit ARM Date: Mon, 22 Oct 2001 17:27:00 -0000 Message-id: X-SW-Source: 2001-10/msg00223.html I'm trying to make GDB work happily on NetBSD/arm26, which runs on ancient ARM processors, where the PC and PSR share R15. As far as I can tell, the code in arm-linux-nat.c, when fetching registers subprocess on a 26-bit CPU, puts the PC in registers[PC_REGNUM], and the PC+PSR in registers[PS_REGNUM]. When putting registers back into the process, it sets R15 (PC+PSR) from registers[PC_REGNUM] and ignores registers[PS_REGNUM]. I suppose my question is: is this the intended behaviour? i.e. should I: (1) do the same on NetBSD, (2) accurately emulate a 32-bit CPU in 26-bit mode (splitting and merging PC and PSR at the subprocess interface), or (3) present GDB with the real state of the CPU? I think my preference is for (2), since this saves complexity in the rest of GDB. -- Ben Harris Portmaster, NetBSD/arm26