On 20 February 2016 at 03:57, Ryan [off-list ref] wrote:

Hi zhaoyang,

On Thu, Feb 18, 2016 at 12:24 PM, Zhaoyang Huang
[off-list ref] wrote:

quoted

Hi Ryan,
As we already known, STR will let all cores power down after store the
context(GPR, idmap_gpd, sp etc) of primary core in DDR. It is
different between ARMv7 and ARMv8
For ARMv7,
The boot vector can just be located in 0x00000000 or 0xffff0000, which
is chosen by sampling VINITHI domain within PMU register during
bootup. For some SOCs, one of them is used for cold boot while another
is used for recover from STR or CPU IDLE, which is referred as warm
reset. For this scenario, an AON RAM is usually placed in one of the
region mentioned above. Meanwhile, the vendor will place some code
there for bring the core back to the context where it is powered down.

I understand that, when the wakeup interrupt arrives - it is not
actually an interrupt but
a reset which executes the code from 0x00000000 and then what happens?

Does it execute the Boot rom and bootloaders all over again - this
does not happen right?

no

My Question is what happens when the wakeup interrupt arrives and how
is it related to
bootloaders/booting process.

For some SOC, there is a RAM on AON(always on) is mapped to 0x00000000
where the resuming codes are placed. The resuming code is responsible for bring
the core back to kernel(to invoke the cpu_resume which will restore the context)

From what i understand - Warm restart is when the reboot command is
issues. How different
is it from cpuidle wakeup or suspend 2 ram wakeup.

I think the rom code will be just used for hotplug when the SOC has been up.

Thanks for your help.

quoted

For ARMv8,
All things are covered by PSCI, you can refer the process from ARM's archive.

On 17 February 2016 at 18:06, Oliver Neukum [off-list ref] wrote:

quoted

On Wed, 2016-02-17 at 15:19 +0530, Ryan wrote:

quoted

Suspend to ram. I am sorry - I did not provide complete information.

STR on ARM is peculiar. I have no idea.

        Sorry
                Oliver


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