On Tue, Jan 24, 2017 at 04:34:40PM +0900, AKASHI, Takahiro wrote:
I have two following questions:
- It takes long time to boot dump-capture kernel, I saw code just to use software method to trigger CPU reset; but looks like the time is a bit long, usually will take > 1 minute. So is this expected? sorry I have not investigate more detailed for the latency.
It takes time to calculate and verify the hash for the second kernel in a purgatory, and it does matter also in kexec.
Pratyush has been proposing his solution here: http://lists.infradead.org/pipermail/kexec/2016-December/017874.html
Thanks for this.
- If system is deadlock on the bus (e.g. AXI, or DDR port), so all CPUs will stall for this case. We can rely on watchdog to trigger SoC reset and preserve DDR contect. After watchdog reset system, what's the general method to boot dump-capture kernel?
whether or not you can boot dump-capture kernel, do you think that you can reset the system, or at least the buses, without losing the contents of the system memory?
I have no expertise for hardware design, so from my limited understanding is hardware can distinguish the reset signal for SoC and for whole board.
Usually watchdog is to trigger SoC reset; so this signal doesn't connect with board level reset signal; in next power cycle we have much chance to preserve DDR content and dump it.
Thanks, Leo Yan