As it was made for the new ROM segment, a piece of the user ram memory segment is taken to create a new memory segment called myram.
Edit your LCF as shown in Listing 5.
MEMORY
{
exception_handlers_p0: org = 0x40000000, len = 0x00001000
pseudo_rom: org = 0x40001000, len = 0x00006800
init: org = 0x40007800, len = 0x00000800
internal_ram: org = 0x40008000, len = 0x00070000
myram: org = 0x40078000, len = 0x00004000
heap : org = 0x4007c000, len = 0x00002000 /* Heap start location */
stack : org = 0x4007e000, len = 0x00002000 /* Start location for
Stack */
}