ES/SHM_BASE_ADDR is a SAP Parameter attribute which is used to control Base virtual address to start allocating segments information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Defines the basis address in the main memory where ESSHM segments are to
be placed.
0 means that ESSHM should use the first free address. However, in some
cases you should explicitly set the value, if another component is
already using the same address.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.