Hi,
From my D7800 router 
Console
U-Boot 2012.07 [local,local] (Jul 01 2015 - 13:18:15)
U-boot 2012.07 dni1 V1.1 for DNI HW ID: 29764958 NOR flash 0MB NAND flash 128MB RAM 512MB 1st Radio 4x4 2nd Radio 4x4 + xDSL
smem ram ptable found: ver: 0 len: 5
DRAM: 491 MiB
.....
Booting Linux on physical CPU 0
Linux version 3.4.103 (figo.yan@dni-l-sw02) (gcc version 4.6.3 20120201 (prerelease) (Linaro GCC 4.6-2012.02) ) #1 SMP Tue Jul 26 14:05:47 EDT 2016
CPU: ARMv7 Processor [512f04d0] revision 0 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache
....
Memory: 49MB 436MB = 485MB total
Memory: 482508k/488652k available, 14132k reserved, 0K highmem
....
Regards,