From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Hovang To: "Hugo 'NOx' Tyson" Cc: ecos-discuss@sourceware.cygnus.com Subject: Re: [ECOS] on ARM: Using the FIQ vector Date: Fri, 28 Jan 2000 07:37:00 -0000 Message-id: <3891B7D3.1DD50A39@cpen.com> References: <38919E4A.8FE2D7D1@cpen.com> X-SW-Source: 2000-01/msg00115.html Hugo 'NOx' Tyson wrote: > > Put another way: > > o short-term masking of *all* interrupts is done using the CPU > register, and you shouldn't let a thread that has done this sleep > whilst interrupts are disabled. (Macros with ENABLE/DISABLE/RESTORE > in them) We need to be able to let the FIQ be enabled constantly, no exceptions. I've removed the eCos FIQ code and rely on the IRQ to handle any timer (scheduling) and devicedriver IRQ's. The goal is that it should be enough to disable the IRQ in any critical sections of the kernel and completely leave the FIQ to the application. > It just *happens* that the CPU reg is preserved rather than always > re-enabled in load_context, because it doesn't really matter. It does to me, I think ... :-) /Dan