Genode (x86_64) reboots on Thinkpad T420

[Valery V. Sedletski]

Alexander Boettcher wrote:
> Hello,
>
> On 07.03.19 23:10, Valery V. Sedletski via users wrote:
>> Hi, Genodians!
>>
>> Some days ago, I ordered a Thinkpad T420, which is listed in Genode
>> unofficial HCL by cnuke. I set up Genode booting remotely via PXE+Intel
>> AMT. It boots the  system image (x86_32 arch) just fine on real
>> hardware. But if I try booting an x86_64 image, it reboots on most
>> kernels, or traps on Fiasco.OC. Last messages in the log I see are from
>> "bender" [1]. This is when booting using NOVA kernel. If I try Fiasco.OC
>> as a kernel ([2]), It goes until "bootstrap", and last I see in the log
>> are "bootstrap" messages, until it attempts to start the kernel. And at
>> the same time, I see the following trap screen from bootstrap: [3]. All
>> registers are zeroes, except a few ones. So, with "foc" kernel, I see a
>> Trap #0 (division by zero). In case of "NOVA" and "base-hw" kernel, it
>> does not trap, but just reboots. I tried to remove the "novga" parameter
>> from NOVA kernel, but I still see a blank screen.
>>
> I could reproduce it after same configuration changes in the UEFI BIOS
> of my test T420. When I set in the UEFI/BIOS the option "Security ->
> Memory Protection -> Execution Prevention" to disabled, the machine 
> reboots.
>
> For my T420 test machine it is set to enabled, and then it works, log
> attached.
>
> Hope it helps,
Yes, that helps. I had "Execution prevention" disabled too. I thought 
that it may cause problems if enabled, but it is vice versa. So, I 
enabled it again. In case of NOVA and Fiasco.OC kernels, it boots now 
fine with "Execution prevention" enabled. With "hw" kernel, it now stops 
after bender's messages, instead of a reboot, though. I'm sorry that I 
didn't tried with "Execution prevention" enabled, before posting the 
message. Didn't wanted to disturb you with no reason

P.S.: I wondered why 32-bit works fine, but cnuke on the irc channel 
supposed that it could be because of NX bit, which is enabled on 32-bit 
normally only if PAE is enabled.

WBR,
valery
> Alex.
>
>
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