Non Volatile Storage

Same as PS3's NVS, used for storing tokens and flags. You can access it by using the function icc_nvs_read (or by ftp'ing the respective regions with root flags server).
Seems that a total of 5 regions(blocks) exist in 2 banks, main bank and backup bank
The kernel accesses only the 5th and the 2nd region, however it's possible to read the other 3.
Most, if not all, of the NVS regions can be accessed also in sflash, starting with offset 0x1C4000.

Mapping of the area (NVS service)

Bank #	Block #	Start Offset	Start Offset in Sflash	Size	Notes
0	0	0	0x1C4000	0x3000	does not match, probably one (sflash or nvs, likely sflash) updates data
0	1	0	0x1C7000	0x1000	match
0	2	0	0x1C8000	0x800	match
0	3	0	0x1C8800	0x800	match? (impossible to know with only retail data)
0	4	0	0x1C9000	0x3000	match

Mapping of the detailed area (NVS service)

Bank #	Block #	Start Offset	Start Offset in Sflash	Size	Notes
0	0	0	0x1C4000	0x8
0	0	0x20	0x1C4020	0x6
0	0	0x50	0x1C4050	0x1
0	0	0x60	0x1C4060	0x5
0	0	0x76	0x1C4076	0x1
0	0	0x7A	0x1C407A	0x6
0	0	0x80	0x1C4080	0x1
0	0	0x96	0x1C4096	0x3
0	0	0x9A	0x1C409A	0x2
0	0	0xAC	0x1C40AC	0x4
0	0	0x7FE	0x1C47FE	0x2
0	0	0x801	0x1C4801	0x1
0	0	0x810	0x1C4810	0x12
0	0	0x84C	0x1C484C	0x2
0	0	0x854	0x1C4854	0x2
0	0	0x870	0x1C4870	0xC
0	0	0x8A0	0x1C48A0	0x1C
0	0	0xFFE	0x1C4FFE	0x2
0	0	0x1000	0x1C5000	0x64
0	0	0x1220	0x1C5220	0x18
0	0	0x1240	0x1C5240	0x18
0	0	0x1260	0x1C5260	0x18
0	0	0x1280	0x1C5280	0x18
0	0	0x12A0	0x1C52A0	0x18
0	0	0x12C0	0x1C52C0	0x18
0	0	0x12E0	0x1C52E0	0x18
0	0	0x1300	0x1C5300	0x18
0	0	0x1320	0x1C5320	0x18
0	0	0x1340	0x1C5340	0x18
0	0	0x1360	0x1C5360	0x18
0	0	0x1380	0x1C5380	0x18
0	0	0x13A0	0x1C53A0	0x18
0	0	0x13C0	0x1C53C0	0x18
0	0	0x13E0	0x1C53E0	0x18
0	0	0x1400	0x1C5400	0x18
0	0	0x1420	0x1C5420	0x18
0	0	0x1440	0x1C5440	0x18
0	0	0x1460	0x1C5460	0x18
0	0	0x1480	0x1C5480	0x18
0	0	0x14A0	0x1C54A0	0x18
0	0	0x14C0	0x1C54C0	0x18
0	0	0x14E0	0x1C54E0	0x18
0	0	0x1500	0x1C5500	0x18
0	0	0x1520	0x1C5520	0x18
0	0	0x1540	0x1C5540	0x18
0	0	0x1560	0x1C5560	0x18
0	0	0x1580	0x1C5580	0x18
0	0	0x15A0	0x1C55A0	0x18
0	0	0x15C0	0x1C55C0	0x18
0	0	0x2000	0x1C6000	0x8
0	1	0	0x1C7000	0x50
0	2	0	0x1C8000	0x4C	Serial Number + model Type (CUH-XXXXX)
0	2	0x60	0x1C8060	0x58
0	2	0xC0	0x1C80C0	0xD
0	2	0x100	0x1C8100	0x20
0	2	0x7D0	0x1C87D0	0x10
0	2	0x7F0	0x1C87F0	0x1
0	4	0	0x1C9000	0x1
0	4	0x20	0x1C9020	0x1	init_safe_mode flag
0	4	0x80	0x1C9070	varies (0x68-0x6C)	acf token <- checked by sceSblDevActVerifyCheckExpire
0	4	0x100	0x1C9100	0x100
0	4	0x200	0x1C9200	varies (0x40-0x60)	scrambled/obfuscated eap hdd key <- checked by g_crypt_deferred_init
0	4	0x900	0x1C9900	0x100	acf signature
0	4	0xC00	0x1C9C00	0x170
0	4	0x1000	0x1CA000	0x300
0	4	0x1300	0x1CA300	0x300
0	4	0x1600	0x1CA600	0x20	checked by regMgrNvsSpInit
0	4	0x2C00	0x1CBC20	0x20
0	4	0x2C40	0x1CBC40	0x20