[9front] qemu kernel for arm64, detected memory

[9front] qemu kernel for arm64, detected memory

[cosarara]

Running 9front on qemu-system-aarch64 (trying to follow the directions in commit dd79854239a8c):

qemu-system-aarch64 -M virt-2.12,gic-version=3 \
                     -cpu cortex-a57 -m 4G -smp 4 \
                     -bios u-boot/u-boot.bin \
                     -drive file=9front-10277.arm64.qcow2,if=none,id=disk \
                     -device virtio-blk-pci-non-transitional,drive=disk \
                     -nographic

u-boot correctly reports:

>   DRAM:  4 GiB

But then plan9:

>   ## Transferring control to Plan 9 (at address 40100000) ...
>   127 holes free
>   0x404c4000 0x429bd000 38768640
>   38768640 bytes free
>
>   Plan 9
>   timer frequency 62500000 Hz
>   cpu0: 1000MHz QEMU
>   127M memory: 41M kernel data, 86M user, 455M swap
>   [...]
>   cirno# cat /dev/swap
>   129220608 memory
>   4096 pagesize
>   9465 kernel
>   2993/22083 user
>   0/94644 swap
>   1556/22083 reclaim
>   1816176/1966560/36545820 kernel malloc
>   0/0/36545820 kernel draw
>   768/65568/16777216 kernel secret

So it seems it does not detect the full amount. I don't know if this is a know bug in the kernel.

Re: [9front] qemu kernel for arm64, detected memory

[Jacob Moody]

On 1/7/24 06:07, cosarara wrote:
> Running 9front on qemu-system-aarch64 (trying to follow the directions in commit dd79854239a8c):
> 
> qemu-system-aarch64 -M virt-2.12,gic-version=3 \
>                      -cpu cortex-a57 -m 4G -smp 4 \
>                      -bios u-boot/u-boot.bin \
>                      -drive file=9front-10277.arm64.qcow2,if=none,id=disk \
>                      -device virtio-blk-pci-non-transitional,drive=disk \
>                      -nographic
> 
> u-boot correctly reports:
> 
>>   DRAM:  4 GiB
> 
> But then plan9:
> 
>>   ## Transferring control to Plan 9 (at address 40100000) ...
>>   127 holes free
>>   0x404c4000 0x429bd000 38768640
>>   38768640 bytes free
>>
>>   Plan 9
>>   timer frequency 62500000 Hz
>>   cpu0: 1000MHz QEMU
>>   127M memory: 41M kernel data, 86M user, 455M swap
>>   [...]
>>   cirno# cat /dev/swap
>>   129220608 memory
>>   4096 pagesize
>>   9465 kernel
>>   2993/22083 user
>>   0/94644 swap
>>   1556/22083 reclaim
>>   1816176/1966560/36545820 kernel malloc
>>   0/0/36545820 kernel draw
>>   768/65568/16777216 kernel secret
> 
> So it seems it does not detect the full amount. I don't know if this is a know bug in the kernel.
> 
> 
> 

This is a known issue. You can set *maxmem in plan9.ini to get it to use more memory.

Thanks,
moody

Re: [9front] qemu kernel for arm64, detected memory

[cosarara]

On 7/1/24 15:23, Jacob Moody wrote:
> This is a known issue. You can set *maxmem in plan9.ini to get it to use more memory.
>
> Thanks,
> moody

Thanks moody. It took me a while to figure it out (it's not easy to edit plan9.ini when its contents make the kernel panic!), so I'm leaving this extra info here for the next person with the same question:

The value for *maxmem (the * is important) for this machine should be the number of bytes = 1GiB + <desired memory>. So the default is 1 * GiB + 128 * MiB = 0x48000000 for 128MiB, and for 4 GiB it should be *maxmem=0x140000000.

cosa