[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV
From: |
Mark Phillips |
Subject: |
[Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler |
Date: |
Wed, 22 Aug 2012 12:14:49 -0000 |
ok, I'll double check that backing out the local patches doesn't make a
difference. If it still happens I will try and come up with a reduced
test case.
What do you expect to happen?
Should the SVC exception 11 run immediately?
What should happen if a clock tick interrupt is also pending at level 15 with a
higher (numerically lower) priority?
What I currently see happening is neither interrupts happen immediately, the
code continues to execute. Then one or more clock tick interrupts occur, before
finally I see the SVC interrupt code running.
Cheers
Mark
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/657006
Title:
arm v7M - svc insn doesn't trigger PendSV handler
Status in QEMU:
New
Bug description:
The svc instruction doesn't work as expected.
-> qemu 0.13.0 rc1 (git)
Test : demo with freeRTOS (for example
FreeRTOS-6.0.5/Demo/CORTEX_LM3S811_GCC) with the card lm3s811evb.
If we start the scheduler, it will call that function (__attribute__
(( naked ))) :
void vPortStartFirstTask( void )
{
__asm volatile(
" ldr r0, =0xE000ED08 \n" /*
Use the NVIC offset register to locate the stack. */
" ldr r0, [r0]
\n"
" ldr r0, [r0]
\n"
" msr msp, r0
\n" /* Set the msp back to the start of the stack. */
" svc 0
\n" /* System call to start first task. */
);
}
The 4 first lines in asm work fine. The scv 0 call will rise the right
interrupt in qemu (line 151, in arm_gic.c, best_irq = 15). However, it will
never call the PendSV Handler (xPortPendSVHandler here). This function is
recorded in the nvic vector.
Next, (after the svc), the processor will execute the line after in code
(this is a naked function) so the next function written after
vPortStartFirstTask in the code.
command line :
console 1 : qemu-system-arm -M lm3s6965evb -kernel gcc/RTOSDemo.axf -s -S
console 2 : arm-none-eabi-gdb -ex "target remote localhost:1234"
gcc/RTOSDemo.axf
arm-none-eabi from
http://www.codesourcery.com/sgpp/lite/arm/portal/release1294
Same error with another project with arm-elf
processor : arm cortex m3
host : gentoo (2.6.35-r9) (without kqemu)
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/657006/+subscriptions
- [Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler, Mark Phillips, 2012/08/20
- [Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler, Mark Phillips, 2012/08/22
- [Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler, Mark Phillips, 2012/08/22
- [Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler, Peter Maydell, 2012/08/22
- [Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler,
Mark Phillips <=
- [Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler, Mark Phillips, 2012/08/22
- [Qemu-devel] [Bug 657006] Re: arm v7M - svc insn doesn't trigger PendSV handler, Mark Phillips, 2012/08/22