IBM Power PC recognise only 1 GB of total RAM

Issue

IBM Power PC model 8202-E4C with RHEL 6.3 (kernel 2.6.32-279.9.1.el6.ppc64) recognise only 1 GB of the 8 GB RAM

[root@host_name]# cat /proc/meminfo
MemTotal:        1006784 kB
MemFree:          165632 kB
Buffers:          116224 kB
Cached:           442112 kB
SwapCached:            0 kB
VmallocTotal:   8589934592 kB
VmallocUsed:       16448 kB
VmallocChunk:   8589859904 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:      16384 kB

[root@host_name]# free -m
             total       used       free     shared    buffers     cached
Mem:           983        820        162          0        113        431
-/+ buffers/cache:        275        707
Swap:         1023          0       1023