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 7 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 5 (also the entirety of it by reading /dev/sflash0s0x34 with BUF_SIZE 0x200 from ftp ).
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 in /dev/sflash0s0x34	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	0x3000	0x1C7000	0x1000	match
0	2	0x4000	0x1C8000	0x800	match, console data region
0	3	0x4800	0x1C8800	0x800	match, all ffs?
0	4	0x5000	0x1C9000	0x3000	match, tokens and flags region
1	0	0x8000	0x1CC000	0x3000	match, tokens and flags region (backup)
1	1	0xB000	0x1CF000	0x1000	match

Mapping of the detailed area (NVS service)

Bank #	Block #	Start Offset in /dev/sflash0s0x34	Start Offset in Sflash	Size	Notes
0	0	0	0x1C4000	0x8	Unknown (e.g 04 01 01 01 01 01 04 01)
0	0	0x20	0x1C4020	0x6	Unknown (e.g 02 BC 60 A7 28 83 66)
0	0	0x4E	0x1C404E	0x2	Unknown (e.g 25 16)
0	0	0x50	0x1C4050	0x5	Unknown (e.g 12 FF 00 00 00)
0	0	0x60	0x1C4060	0x5	Unknown (e.g 04 02 01 01 02)
0	0	0x73	0x1C4073	0x1	Unknown (e.g 01)
0	0	0x76	0x1C4076	0x1	Unknown (e.g 01)
0	0	0x7A	0x1C407A	0x6	Unknown (e.g 00 00 00 00 00 38)
0	0	0x80	0x1C4080	0x1	Unknown (e.g. 00)
0	0	0x82	0x1C4082	0x3	Unknown (e.g. 01 01 01)
0	0	0x91	0x1C4091	0x2	Unknown (e.g 00 00)
0	0	0x96	0x1C4096	0x3
0	0	0x9A	0x1C409A	0x2	Unknown (e.g 02 02)
0	0	0x9E	0x1C409E	0x2	Unknown (e.g 00 00)
0	0	0xA0	0x1C40A0	0x3	Unknown (e.g 01 01 01)
0	0	0xAC	0x1C40AC	0x4
0	0	0xC5	0x1C40C5	0x3	Unknown (e.g AA AA AA)
0	0	0x204	0x1C4204	0x1	Unknown (e.g 00)
0	0	0x20B	0x1C420B	0x1	Unknown (e.g 00)
0	0	0x210	0x1C4210	0x2	Unknown (e.g 49 42)
0	0	0x7FE	0x1C47FE	0x2	Unknown (e.g AF 31)
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	0x3000	0x1C7000	0x40
0	1	0x3040	0x1C7040	0x10	trsw_attach (e.g 1F FF 00 00 07 FF FF 07 FF FF 00 00 00 00 00 00)
0	1	0x30A0	0x1C70A0	0x2	get_icc_max (e.g 20 9A)
0	2	0x4000	0x1C8000	0x4C	Serial Number + model Type (CUH-XXXXX), see below
0	2	0x4010	0x1C8010	0x10	SOCUID
0	2	0x4030	0x1C8030	0x11	Used in 5.05, Unique Identifier of Console, hw_info (e.g 00TS4DB00K2180050)
0	2	0x4041	0x1C8041	0x1F	Used in later firmwares, Unique Identifier of Console, hw_model (e.g DUT-DBW00JK-S0ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ)
0	2	0x4060	0x1C8060	0x58
0	2	0x40C0	0x1C80C0	0xD
0	2	0x4100	0x1C8100	0x20	(e.g 00 02 F4 C1 64 E6 83 41 0C D0 8D 91 38 56 50 AE 15 3E 60 9E 70 16 17 1A 1C 18 26 25 1B 1B F5 F7)
0	2	0x47D0	0x1C87D0	0x10	all zeroes usually (e.g 01 01 01 01 01 01 01 01 01 00 00 00 00 00 00 00)
0	2	0x47F0	0x1C87F0	0x1	(e.g 01)
0	4	0x5000	0x1C9000	0x20	dipswitch flags, see below
0	4	0x5000	0x1C9000	0x1	SCE_REGMGR_ENT_KEY_DEVENV_TOOL_boot_param (FE Development Mode) (FB Assist Mode) (FF Release Mode)
0	4	0x5003	0x1C9003	0x1	Memory Budget (0xFF Normal, 0xFE Large)
0	4	0x5005	0x1C9005	0x1	Slow HDD Mode (0xFE ON) (0xFF OFF)
0	4	0x500B	0x1C900B	0x1	Unknown (0x87 on proto devkit)
0	4	0x5010	0x1C9010	0x1	vsh_4K Mode (0xFE ON) (0xFF OFF)
0	4	0x5020	0x1C9020	0x1	init_safe_mode flag
0	4	0x5021	0x1C9021	0x1	sysctl_machdep_cavern_dvt1_init_update
0	4	0x5030	0x1C9030	0x1	trsw_probe (01 for [ WLAN mode : FT ], else [ WLAN mode : OFF ]) also bt_sdio_probe and trs_probe
0	4	0x5038	0x1C9038	0x1	ethernet related (gbe)
0	4	0x5050	0x1C9050	0x1	is_extra_clock_available_rtc_status
0	4	0x5064	0x1C9064	0x4	sdk version?
0	4	0x5070	0x1C9070	0x4	manu_mode related (sdk version?)
0	4	0x5074	0x1C9074	0x4	Unknown (e.g. 84 72 4E 57)
0	4	0x507C	0x1C907C	0x4	manu_mode related (sdk version?)
0	4	0x5080	0x1C9080	varies (0x68-0x6C)	acf token <- checked by sceSblDevActVerifyCheckExpire
0	4	0x5100	0x1C9100	0x100	sce_cam_error_put
0	4	0x5200	0x1C9200	varies (0x40-0x60)	scrambled/obfuscated eap hdd key <- checked by g_crypt_deferred_init, also checked by read_idstorage
0	4	0x5301	0x1C9301	1	unknown (01 = enabled)
0	4	0x5311	0x1C9311	1	unknown (01 = enabled)
0	4	0x531F	0x1C931F	1	UART boot param? (setting this to 1 enables UART output on boot)
0	4	0x5320	0x1C9320	1	lvp_configure_get_gddr5clk
0	4	0x5322	0x1C9322	1	lvp_configure_tccds
0	4	0x5329	0x1C9329	1	related to lvp_config
0	4	0x5400	0x1C9400	0x210	token ???
0	4	0x5650	0x1C9650	0x290	qafutkn_ioctl
0	4	0x5900	0x1C9900	0x100	acf signature
0	4	0x5A00	0x1C9A00	0x190	token ???
0	4	0x5C00	0x1C9C00	0x3C	HDD Info (e.g GHTSH ST4501019A6E08 613081DJ0124FZD129SN)
0	4	0x5C3C	0x1C9C3C	0x04	Unknown (e.g 05 C6 0A 00)
0	4	0x5C40	0x1C9C40	0x130	setPupExpirationStatus
0	4	0x6000	0x1CA000	0x300	wrappNvsRead, or regMgrNvsRead
0	4	0x600E	0x1CA00E	0x1	Unknown (Not Regions)
0	4	0x6040	0x1CA040	0x1	Circle Button Behaviour (0x01 is Circle Go Back) (0x00 is Circle Accept)
0	4	0x6300	0x1CA300	0x300	wrappNvsRead, or regMgrNvsRead
0	4	0x6600	0x1CA600	0x20	Modes (See Below)
0	4	0x6600	0x1CA600	0x1	SCE_REGMGR_ENT_KEY_SYSTEM_SPECIFIC_idu_mode (0x01 Enabled 0x00 or 0xFF Disabled)
0	4	0x6601	0x1CA601	0X1	SCE_REGMGR_ENT_KEY_SYSTEM_update_mode (0xFF or 0x00 disabled) (0x10, 0x20, 0x30, 0x31, 0x32, 0x50 enabled)
0	4	0x6602	0x1CA602	0x1	SCE_REGMGR_ENT_KEY_SYSTEM_SPECIFIC_show_mode (0x01 Enabled 0x00 Disabled) (Testkit Only!)
0	4	0x6603	0x1CA603	0x1	SCE_REGMGR_ENT_KEY_REGISTRY_recover
0	4	0x6604	0x1CA604	0x4	SCE_REGMGR_ENT_KEY_SYSTEM_soft_version (deprecated) (devkit only?)
0	4	0x6609	0x1CA609	0x1	SCE_REGMGR_ENT_KEY_SYSTEM_SPECIFIC_arcade_mode
0	4	0x7C00	0x1CBC00	0x20	manu mode (all zeroes for enabled, all ffs for disabled)
0	4	0x7C40	0x1CBC40	0x20
0	4	0x7CC0	0x1CBCC0	0x20	srtc_modevent
?	?	???	0x1CC31F	1	UART boot param? (setting this to 1 enables UART output on boot)
?	?	???	0x1CF000	1	?? FF disabled 00 enabled