> -----Original Message----- > From: Philippe Mathieu-Daudé <philippe.mathieu.da...@gmail.com> On > Behalf Of Philippe Mathieu-Daudé > Sent: Monday, January 25, 2021 10:30 AM > To: Taylor Simpson <tsimp...@quicinc.com>; qemu-devel@nongnu.org > Cc: a...@rev.ng; alex.ben...@linaro.org; richard.hender...@linaro.org; > laur...@vivier.eu; Brian Cain <bc...@quicinc.com> > Subject: Re: [PATCH v7 15/35] Hexagon (target/hexagon/arch.[ch]) utility > functions > > >>> diff --git a/target/hexagon/arch.c b/target/hexagon/arch.c > >>> new file mode 100644 > >>> index 0000000..c59cad5 > >>> --- /dev/null > >>> +++ b/target/hexagon/arch.c > >> ... > >> > >>> +#define RAISE_FP_EXCEPTION \ > >>> + do {} while (0) /* Not modelled in qemu user mode */ > >> > >> I don't understand why... Can you explain please? > > > > Our Linux kernel only sets the relevant bits in USR (user status register). > The exception isn't raised to user mode. > > Hmm while you introduce the linux-user implementation of your port, > this file is not restricted to user mode. Thinking about avoiding > head aches to someone wanting to add system mode emulation (or a > BSD port??), maybe your helpers should consider that. > Maybe some cheap #ifdef'ry CONFIG_USER_ONLY with a comment > explaining > why there is nothing to do in user mode, and g_assert_not_reached() > else. Not sure, just wondering...
Sorry, I misunderstood the question. You are correct. It's a placeholder for future work to support system mode. I'll add the #ifdef and some comments to explain. Thanks, Taylor