Re: [PATCH v2 0/2] Make it possible to reserve memory on 64bit platform

From: David Hildenbrand
Date: Mon Jan 18 2021 - 05:18:43 EST


On 18.01.21 04:51, zhaowei1102@xxxxxxxxxxxxxxx wrote:
> On Sat, Jan 16, 2021 at 2:43 AM Wesley Zhao
> <zhaowei1102@xxxxxxxxxxxxxxx> wrote:
> >>
> >> I was trying to reserve some memory to save logs incase that
> Android panic or hang and then
> >> I can read the logs from QNX side from the memory reserved before
> on the Qualcomm 8155 hypervisor platform,
> >> and I find the "reserve=" parameter only support 32bit,so I made
> some change and send these patches.
>
> >See Documentation/admin-guide/kernel-parameters.txt
>
> >        memmap=nn[KMG]$ss[KMG]
> >                        [KNL,ACPI] Mark specific memory as reserved.
> >                        Region of memory to be reserved is from ss
> to ss+nn.
> >                        Example: Exclude memory from
> 0x18690000-0x1869ffff
> >                                 memmap=64K$0x18690000
> >                                 or
> >                                 memmap=0x10000$0x18690000
> >                        Some bootloaders may need an escape character
> >before '$',
> >                        like Grub2, otherwise '$' and the following
> number
> >                        will be eaten.
> Sorry,what is your point:
>  static int __init reserve_setup(char *str)
>  static struct resource reserve[MAXRESERVE];
>  for (;;) {
>  unsigned int io_start, io_num;*  // these code is not compatible
> with 64bit,i start from here*
>

Dan's point is that you should look into using "memmap=" instead of
"reserve=".

--
Thanks,

David / dhildenb