Hi Adrian,

Thanks for your explanation. It’s very clear.
We’ll find another platform timer to satisfy the design of seL4 timer driver.

BRs,
Jesse
From: [email protected] [mailto:[email protected]]
Sent: Thursday, May 25, 2017 10:26 AM
To: Jesse-SC Chou (周書正); [email protected]
Subject: Re: [seL4] About timer tests (CONFIG_HAVE_TIMER) in sel4test testsuites

Hi Jesse,

The ARM generic timer is typically used by the kernel as its timer source for 
scheduling preemption. The CONFIG_HAVE_TIMER require an additional timer that 
is passed to user level. On the TK1 this is TMR1, on the hikey its the DMTIMER, 
on other platforms it's the EPIT etc. What timer did you use to implement 
sel4platsupport_get_default_timer? If the CONFIG_HAVE_TIMER tests are not 
passing then that indicates a bug in that time driver.

The ARM generic timer cannot be exported to user level as it would be unsafe 
for the kernel to share it, and the kernel needs the generic timer as its the 
only per-core timer. For this reason you'll need an implementation of another 
platform specific timer.

Adrian
On Wed 24-May-2017 7:48 PM, Jesse-SC Chou (周書正) wrote:
Hi seL4-hackers,

I am porting the sel4test project to my custom target board, which contains an 
ARM Cortex-A7 core.
The porting work is based on NVidia TK1 Cortex-A15 platform.
In current stage, the seL4 kernel has booted up and the test benches can be 
tested.
I can pass all tests except for the timer tests (turn off CONFIG_HAVE_TIMER).
In my target, only ARM generic timer is used.

My questions are:
1. Are the timer tests (CONFIG_HAVE_TIMER) designed for other platform timer 
besides ARM generic timer?
If I only use ARM generic timer, should these timer tests be passed?

2. My goal is to running Linux with seL4 VMM on my target. The 
sel4platsupport_get_default_timer() is platform specific.
If I only use ARM generic timer, should sel4platsupport_get_default_timer() be 
ported to return the ARM generic timer?
If yes, is there any example for me to reference?

BRs,
Jesse




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