memmap

memmap=nn[KMG]@ss[KMG]
[KNL] Force usage of a specific region of memory
Region of memory to be used, from ss to ss+nn.

memmap=nn[KMG]#ss[KMG]
[KNL,ACPI] Mark specific memory as ACPI data.
Region of memory to be used, from ss to ss+nn.Linux

memmap=nn[KMG]$ss[KMG]
[KNL,ACPI] Mark specific memory as reserved.
Region of memory to be used, from ss to ss+nn


Ref:
http://www.delightpress.com.tw/bookothers/SKNS00005-%E9%99%84%E9%8C%84B.pdf