dts - linux,usable-memory

[Laurentiu-Cristian Duca]

On 8/2/23, Laurentiu-Cristian Duca <laurentiu.duca at gmail.com> wrote:
> On 8/2/23, Conor Dooley <conor at kernel.org> wrote:
>> Hey,
>>
>> On Wed, Aug 02, 2023 at 04:51:47PM +0300, Laurentiu-Cristian Duca wrote:
>>>   my name is laurentiu-cristian duca and i am an open-source enthusiast.
>>> lately i have tried to use the linux,usable-memory in the dts memory
>>> node
>>> and linux freezes.
>>>   if i use only reg, linux boots fine.
>>>   does anybody used linux,usable-memory and can you show a working
>>> example.
>>>
>>>   here is what i tried
>>>         memory at 80000000 {
>>>                 device_type = "memory";
>>>                 reg = <0x0 0x80000000 0x0 0x700000>;
>>>                 //linux,usable-memory = <0x80000000 0x700000>;
>>>         };
>>
>> What are you actually doing when you freeze? A normal boot? Kexec?
>> What hardware is this?
>> Are you using OpenSBI, and if so what version?
>> What version of the kernel is this?
>
>   linux5.13.19 with busybox minimal rootfs, bbl (berkeley boot loader),
> hardware fpga board with only uart and memory 8MB
> i simulate in verilator the verilog sources and i have success if the
> dts has reg.
>  when it freezes, i can not see any message in simulation
[    0.000000] Linux version 5.13.19 (laur at laurPC-100)
(riscv32-linux-gcc.br_real (Buildroot 2021.08) 11.1.0, GNU ld (GNU
Binutils) 2.37) #402 SMP Wed Aug 2 15:27:14 EEST 2023
[    0.000000] OF: fdt: memory scan node memory at 80000000, reg size 8,
[    0.000000] Machine model: kise-lab,simrv
[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
[    0.000000] printk: bootconsole [sbi0] enabled
[    0.000000] printk: debug: ignoring loglevel setting.
from here i can not see anything


> if you want to, i can send you the sources
>
>   please tell me if the dts memory property is written correctly for
> linux,usable-memory
>
> thank you,
> laurentiu
>>
>> Thanks,
>> Conor.
>>
>