Agree with Ciro. What do you mean by PC here anyway?
"Also I notice that the thumb version traps, but gives me some other PC which doesn't actually correspond to the illegal instruction" Are you referring to the value stored in the ELR_EL1 (Exception link register) or the PC of the exception handler? Giacomo -----Original Message----- From: gem5-dev <[email protected]> On Behalf Of Ciro Santilli Sent: 09 April 2020 13:30 To: gem5 Developer List <[email protected]> Subject: Re: [gem5-dev] qemu ARM not dying on m5 ops? Send an email to the QEMU mailing list with the instruction encoding, possibly CC Peter Maydell, he usually replies super fast 🙂 ________________________________ From: gem5-dev <[email protected]> on behalf of Gabe Black <[email protected]> Sent: Thursday, April 9, 2020 1:24 PM To: gem5 Developer List <[email protected]> Subject: [gem5-dev] qemu ARM not dying on m5 ops? Hi ARM folks. I'm trying to run my shiny new instruction based m5 op test on QEMU for ARM, and it's not actually exploding with an illegal instruction when it tries to run an m5 op. I've tried this with the older version of the utility as well, and I see the same behavior. I've dug into it, and the encoding is doing a move from a coprocessor register into a regular register I think, and operating on coprocessor 1. I *think* if the coprocessor doesn't exist, the CPU is supposed to trap somehow, and not just plow ahead. Is this something wrong with QEMU? Do I need to pass it some magical flag to get it to work like I expect? I'm not super worried about how correct QEMU is, but I want to make sure the code in the m5 utility is correct. It would be nice if QEMU ran it correctly too, since that would be a nice independent way to verify that the utility is still working. Any help would be appreciated! Also I notice that the thumb version traps, but gives me some other PC which doesn't actually correspond to the illegal instruction. I'm not sure what's going on there. I'll probably try running these on real ARM hardware I have with me to see if they do what I want there. Gabe _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
