Search found 11 matches

by wpaul
Wed Feb 13, 2019 12:00 am
Forum: Bug Reports
Topic: Stack guard pages on Cortex-M4 Topic is solved
Replies: 3
Views: 363

Re: Stack guard pages on Cortex-M4 Topic is solved

You know, I looked right at the port_extctx part of PORT_WA_SIZE() several times without realizing what it was for. Sorry for being so thick and thanks for pointing that out to me. When I first turned on the stack guard feature, I found that I did have to increase PORT_INT_REQUIRED_STACK a little in...
by wpaul
Mon Feb 11, 2019 1:08 am
Forum: Bug Reports
Topic: Stack guard pages on Cortex-M4 Topic is solved
Replies: 3
Views: 363

Stack guard pages on Cortex-M4 Topic is solved

Hi: I'm still working on a hobby project using the Nordic Semi nRF54820 which uses a Cortex-M4 core. Since it includes MPU support, I decided to try experimenting with the PORT_ENABLE_GUARD_PAGES feature. I got it to work, but I ran into a couple of unusual issues. I'm not sure if they're bugs per s...
by wpaul
Thu Oct 25, 2018 11:59 pm
Forum: ChibiOS/RT
Topic: Priority order violation (different question :) )
Replies: 7
Views: 624

Re: Priority order violation (different question :) )

Quick update: with the priorities adjusted as shown previously, the target has been running for a couple of days now without any problems, with all the debug checks and asserts enabled. I still don't understand exactly how the interrupt priority assignments can lead to the "priority order viola...
by wpaul
Tue Oct 23, 2018 10:06 pm
Forum: ChibiOS/RT
Topic: Priority order violation (different question :) )
Replies: 7
Views: 624

Re: Priority order violation (different question :) )

"Also consider that LR does not contain the usual magic value on ISR entry, it contains a real return address." If you mean the SoftDevice is not passing through the right EXC_RETURN value in the link register, that does not appear to be the case. The Nordic engineers seem to have thought ...
by wpaul
Mon Oct 22, 2018 9:45 pm
Forum: ChibiOS/RT
Topic: Priority order violation (different question :) )
Replies: 7
Views: 624

Re: Priority order violation (different question :) )

I had considered trying to intercept the interrupts first, but there are complications. For example, remember that the SoftDevice assumes it will capture interrupts first and then forward them. If I capture them first, then call the SoftDevice, the SoftDevice will then attempt to forward them again....
by wpaul
Mon Oct 22, 2018 7:10 pm
Forum: ChibiOS/RT
Topic: Priority order violation (different question :) )
Replies: 7
Views: 624

Priority order violation (different question :) )

So, recently I turned on the CH_DBG_ENABLE_ASSERTS flag in chconf.h for my project (along with other checks) and it exposed some problems. Most were easily fixed, but I also ran into the "priority order violation" problem. I *think* I've actually fixed it now, but I'm trying to understand ...
by wpaul
Mon Sep 24, 2018 10:08 pm
Forum: Bug Reports
Topic: Bug in the m25qStop() function in m25q.c driver Topic is solved
Replies: 3
Views: 430

Re: Bug in the m25qStop() function in m25q.c driver Topic is solved

Oops, I just realized: instead of version 18.1.2, that should be 18.2.1. My bad.

-Bill
by wpaul
Mon Sep 24, 2018 6:13 pm
Forum: Bug Reports
Topic: Bug in the m25qStop() function in m25q.c driver Topic is solved
Replies: 3
Views: 430

Bug in the m25qStop() function in m25q.c driver Topic is solved

Hello: This weekend I wrote a QSPI driver for ChibiOS for a project I'm working on. I got things to work, but along the way I discovered a bug in the m25qStop() function which I thought I should report. Relevant details: OS version: ChibiOS 18.1.2 release Platform: Nordic nRF52840 DK development boa...
by wpaul
Fri Oct 14, 2016 8:22 pm
Forum: Development and Feedback
Topic: Question about __set_PSP()/__set_MSP()
Replies: 4
Views: 1385

Re: Question about __set_PSP()/__set_MSP()

"Updating PSP does affect SP in process mode, likewise modifying MSP does affect SP in exception mode. There is no real SP register. SP is the name for current one." Okay, so that means "sp" is in fact aliased to MSP when in exception context and aliased to PSP when in user conte...
by wpaul
Thu Oct 13, 2016 6:59 pm
Forum: Development and Feedback
Topic: Question about __set_PSP()/__set_MSP()
Replies: 4
Views: 1385

Re: Question about __set_PSP()/__set_MSP()

I'm still not sure I understand. It seems the implication is that the stack pointer is aliased to either MSP or PSP depending on the circumstances. However if that's the case, I still don't see how clobber protection makes sense. If sp is currently aliased to MSP and you update PSP, the current sp s...

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