From: Mike Rapoport <rppt@xxxxxxxxxxxxx> The existing description of mem= does not cover all the cases and differences between how architectures treat it. Extend the description to match the code. Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> --- This is in a way a followup for the discussion of mem= usage on MIPS: https://lore.kernel.org/all/1646461289-31992-1-git-send-email-yangtiezhu@xxxxxxxxxxx .../admin-guide/kernel-parameters.txt | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f5a27f067db9..f3597841a031 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2834,6 +2834,15 @@ 2 when the kernel is not able to see the whole system memory; 3 memory that lies after 'mem=' boundary is excluded from the hypervisor, then assigned to KVM guests. + 4 to limit the memory available for kdump kernel. + + [ARC,MICROBLAZE] - the limit applies only to low memory, + high memory is not affected. + + [ARM64] - only limits memory covered by the linear + mapping. The NOMAP regions are not affected. + + [HEXAGON] - must be use to set the memory size, there is [X86] Work as limiting max address. Use together with memmap= to avoid physical address space collisions. @@ -2844,6 +2853,17 @@ in above case 3, memory may need be hot added after boot if system memory of hypervisor is not sufficient. + mem=nn[KMG]@ss[KMG] + [ARM,MIPS] - override the memory layout reported by + firmware. + Define a memory region of size nn[KMG] starting at + ss[KMG]. + Multiple different regions can be specified with + multiple mem= parameters on the command line. + + mem=nn[KMG] [HEXAGON] Set the memory size. + Must be specified, otherwise memory size will be 0. + mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel memory. -- 2.34.1
