KBL Param

The KBL Param buffer (temporary name was sysroot buffer) is a 0x100 or 0x200 sized buffer passed to the Secure Kernel BootLoader in the scratch space and contains all sorts of flags and system parameters. This buffer is created in Second Loader copied to Secure Kernel, passed to the Secure and Non-Secure Kernel BootLoaders, and the non-secure kernel. It is used by many functions to check for features that are enabled for the system. The strategy in this buffer is to compute once for all the information that is often used, to share it between all security layers not to have to implement generator code many times, and to implement the generation code in the most secure layer: second_loader (excluding first_loader).

Offset	Size	Description
0x0	0x2	Version (usually 1)
0x2	0x2	Size. Size of this structure. 0x100 or 0x200
0x4	0x4	Current Firmware Version
0x8	0x4	Minimum Firmware Version
0xC	0x14	unk
0x20	0x10	QA flags
0x30	0x10	Boot flags
0x40	0x20	DIP Switches
0x60	0x4	DRAM base paddr (0x40000000)
0x64	0x4	DRAM size (0x20000000 on retail and testkit, 0x40000000 on DevKit in DevKit Memory Size mode)
0x68	0x4	unk
0x6C	0x4	Boot type indicator 1 (0x20000 on resume - no boot logo, 0x1 on boot - boot logo, 0x4 manufacturing mode)
0x70	0x10	OpenPsId
0x80	0x4	secure_kernel.enp raw data paddr (optional)
0x84	0x4	secure_kernel.enp size (optional)
0x88	0x4	context_auth_sm.self raw data paddr
0x8C	0x4	context_auth_sm.self size
0x90	0x4	kprx_auth_sm.self raw data paddr
0x94	0x4	kprx_auth_sm.self size
0x98	0x4	prog_rvk.srvk raw data paddr
0x9C	0x4	prog_rvk.srvk size
0xA0	0x8	PSCode
0xA8	0x8	unk
0xB0	0x10	Session ID
0xC0	0x4	Unknown, comes from syscon cmd 3
0xC4	0x4	Wakeup factor
0xC8	0x4	Unknown, comes from syscon cmd 0x800 (?Device model dependant?) (ex: 0x40, 0x60, 0x64, 0x3D2, 0xC001C0)
0xCC	0x4	Unknown, comes from syscon cmd 0x100 (0x74FFFFFF on coldboot, 0x74FFBFFF on warmboot, 0x36AFFFXX triggers SetProductMode on 0.940)
0xD0	0x4	Saved context paddr, comes from syscon cmd 0x90 offset 0xC
0xD4	0x4	Hardware Info
0xD8	0x4	Boot type indicator 2
0xDC	0xC	unk
0xE8	0x10	Hardware flags, comes from syscon cmd 6
0xF8	0x4	BootLoader Revision
0xFC	0x4	Sysroot Magic value (0xCBAC03AA)
0x100	0x20	Encrypted Session Key (FW 2.12+)

QA flags

In the following table bytes are counted from left to right and bits from left to right too.

Byte (0-0xF) - mask (1 << (bit - 1))	Description	Used in
Byte 0x6 - mask 2	Allow ScreenShot Always, Np Full Test, Limited Debug Menu Display	Shell, Settings
Byte 0xC - mask 4	Set to skip version checks in system updates, Allow DevKit PspEmu	Updater, Compat
Byte 0xC - mask 2	Allow All Debug Menu Display	Settings
Byte 0xD - mask 1	Allow Kernel Debug, Allow F00D Debug	secure_kernel, most NS and S kernel modules
Byte 0xD - mask 2	Allow Remote Sysmodule Load, Dictates if you can pass arguments to sceAppMgrLaunchAppByPathForDriver	secure_kernel, SceAppMgr
Byte 0xE - mask 1	Disable ASLR	second_loader, secure_kernel
Byte 0xF - mask 1	Allow NonQA Pup, Minimum Debug Menu Display	secure_kernel, Updater, Settings

To check: Byte 0xF bit 7, byte 0xE bit 7, byte 0xE bit 6, byte 0xB bit 3: Revocation related.

The data below contains QA Flags captured (at 0x20 in sysroot buffer) from a System Debugger unit (SD DEM):

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00000020  33 00 00 00 00 00 07 05 73 01 00 01 06 03 03 01  3.......s.......

Boot flags

Bit	Description
47	use internal storage

• at 0x30: 0xFF - not update mode
• at 0x33: 0xFF - not safe mode
• at 0x35: FF on FAT - no internal storage or on PSTV or SLIM - internal storage enabled, FE on PSTV or SLIM - internal storage disabled

Hardware Info

Data returned by Ernie.

• 00 60 41 00: PDEL-1XXX
• 00 60 40 00: PCH-10XX / PTEL-1XXX
• 02 60 40 00: PCH-11XX
• 38 22 82 00: PCH-2XXX model revision 0x18
• 30 30 70 00: VTE-XXXX

Bytes meaning

Little-endian as usual.

First byte

• 00 -> FAT WIFI
• 02 -> FAT 3G. This is what SceBbmc checks.
• 30 -> PSTV model revision 0x18
• 38 -> SLIM

Bit flags

Bit	Description
2	PSTV Slim
3	PSTV Slim
4	Slim
6	3G Modem
9	Fat
10	always set
11	PSTV
16	Slim
17	PSTV Fat
18	PSTV
19	PSTV
20	?Communication Processor?
22	Slim

Boot type indicator 2

Experimental point of view

- No AC connected + No POWER Button pressed: 0x0
ex: rebooting by software PSVita when AC is not connected

- No AC connected + POWER Button pressed: 0x4
ex: booting PSVita by pressing POWER button when AC is not connected

- AC connected + No POWER Button pressed: 0x8
ex: rebooting by software PSVita when AC is connected
ex: autobooting PSTV/IDU PSVita by pluging AC

- AC connected + POWER Button pressed: 0xC
ex: powering off by software PSTV then booting it by pressing POWER button
ex: booting PSVita by pressing POWER button when AC is connected

Bit flags point of view

Bit	Description
0	AC: connected: 1 - disconnected: 0 (note that PSTV always has AC connected)
1	POWER button: pressed: 1 - not pressed: 0

Wakeup factor

• 14 FF 00 00
• 04 FF 00 00 after normal reboot
• 04 00 00 00
• 00 FF 00 00
• 80 after suspend

DIP Switches

DIP switches area embeds two parts: Communication Processor information as 32-bit integers, followed by DIP switches stored as bit flags.

Offset	Size	Description
0x40	0x4	CP Timestamp 1 (ex: 0x4AD86AB3 -> 16/10/2009 14:44:35)
0x44	0x2	CP Version (ex:0x1301 => 1301 on PDEL-100x)
0x46	0x2	CP Board ID (3 on DEM-300xH, 4 on PDEL-100x)
0x48	0x4	CP Timestamp 2 (identical as 1)
0x4C	0x4	ASLR Seed (?USER flags?) (also set on Retail and TestKit) (ex: 0x00000000 on a DEM-300xH)
0x50	0x4	SDK (SCE) flags (ex: 0x80000000 or 0x80000001 or 0x80000003 or 0x81000000 or 0x81000001 OR 0x0 or 0x2 in release mode)
0x54	0x4	SHELL flags (ex: 0x00000000 on a DEM-300xH)
0x58	0x4	Debug control flags (ex: 0x000413e7 on a DEM-300xH, 0x1453E7 dev mode, 0x080002 release mode)
0x5C	0x4	System control flags (ex: 0x2000001c on a DEM-300xH, 0x20000010 dev mode, 0x20000000 release mode)

DIP Switches bit flags resolving

Warning: DIP Switches bit flags actually start at offset 0x10 (before that is CP information), which implies the first bit flag number is 128 (bit_num = offset / 8).

DIP Switches bit flags follow little-endian logic, which makes it hard to visualize in commonly used big-endian hexadecimal:

• ((uint32_t *)kbl_param->dipsw[0x10])[0] = 0x00000001 (big-endian in hex) = 01 00 00 00 (little-endian in hex) = 10000000 00000000 00000000 00000000 (little-endian in base 2) <- the 1 corresponds to bit flag number 128
• ((uint32_t *)kbl_param->dipsw[0x10])[0] = 0x00000002 (big-endian in hex) = 02 00 00 00 (little-endian in hex) = 01000000 00000000 00000000 00000000 (little-endian in base 2) <- the 1 corresponds to bit flag number 129
• ((uint32_t *)kbl_param->dipsw[0x10])[0] = 0x00000100 (big-endian in hex) = 00 01 00 00 (little-endian in hex) = 00000000 10000000 00000000 00000000 (little-endian in base 2) <- the 1 corresponds to bit flag number 136
• ((uint32_t *)kbl_param->dipsw[0x10])[0] = 0x80000000 (big-endian in hex) = 00 00 00 80 (little-endian in hex) = 00000000 00000000 00000000 00000001 (little-endian in base 2) <- the 1 corresponds to bit flag number 159

As you can see this way is not convenient to know in memory on which byte corresponds which bit flag, so instead we can use a formula to convert bit number to offset and bit: offset = (bit_num / 32) * 4, bit = bit_num & 31. This is used for example in the following code:

SceBool sceKernelCheckDipswForDriver(SceUInt32 no) {
  return (*(SceUInt32 *)(kbl_param->dipsw + (no >> 5) * 4) >> (no & 31)) & 1;
}

CP Information

Bits 0-31 is a 32-bit integer of the current time on the CP clock. This is duplicated in bits 64-95.

Bits 32-47 is a 16-bit integer of the CP version and bits 48-63 is a 16-bit integer of the CP board ID. All integers are little-endian. On units that do not have a CP, these fields are zeroes.

Bits 96-127 is 32-bit integer ASLR seed that is randomized on each boot in second loader. It can be disabled by setting a specific DIP switch or QA flag byte 0xE mask 1.

Bits 0-63 are also manipulable as general purpose DIP Switches exposed with sceKernelSetDipsw, sceKernelClearDipsw, and sceKernelCheckDipsw but these functions do not change anything in hardware (only cached values are overwritten in SceSysmem).

According to SDK only DIP Switches 0-63 are accessible from usermode, however:

• On FW 0.990 (but not on FW 0.931 nor 3.60), DIP Switch number 237 is the only one out of range 0-63 that can be set from usermode.
• Usermode SELFs can use DIP Switches number > 63 if they have a special attribute or capability in SELF Auth Info.

SDK (SCE) flags

Bits 128-159 are used for DevKit Boot Parameters.

Bit	Description
128	Memory Size. (Extended game memory) On: 1 - Off: 0
129	Release Mode Console. On: 1 - Off: 0
152	PS TV Emulation. On: 1 - Off: 0
159	Release Check Mode. Development Mode: 1 - Release Mode: 0

Shell flags

Bits 160-191 are used for SceShell flags.

Bit	Description
168	Memory Size: Console Size: 1 - Development Tool Size: 0
184	Enable extra TTY: On: 1 - Off: 0. (tty7:)
185	Enable System Boot Time Notifications: On: 1 - Off: 0
187	Allow processes to run on all cores (CPU affinity): On: 1 - Off: 0

Debug control flags

Bits 192-223 are for various debug options.

Bit	Description
192	?
193	Enable SDbgSdio
194	Enable CP (if disabled it disables Cpup, DbgSdio and UsbDbg)
195	Disable USB Debug. nouse_dbgusb (if enabled, SceUsbDbg doesn't init)
196	Enable kernel UART console logging (if enabled, UART is initialized and SceDebug handlers are set to UART functions).
197	Enable kernel console logging: On: 1 - Off: 0
199	Enable TTY stdio ("tty0:"): On: 1 - Off: 0
200	Stop when an assertion fails: On: 1 - Off: 0
201	Set minimum assertion level to 1: On: 1 - Off: 0
202	Set minimum assertion level to 2: On: 1 - Off: 0
210	Allow Kernel Budget (related to memblock types)
211	Enable usermode UART console logging?
212	?
214	Disable ASLR
216	Used on FW 0.990 by functions SceThreadmgrForKernel_CA84C603 and SceThreadmgrForKernel_05F5306C

System control flags

Bits 224-255 are used for various system options.

Bit	Description
224	Allows loading sd0:psp2-config.txt
228	Allows getting and setting Process and Thread HBP and HWP. sceKernelGetPHWPForKernel, sceKernelSetPHWPForKernel, sceKernelGetPHBPForKernel, sceKernelSetPHBPForKernel, sceKernelGetTHBPForDriver, sceKernelSetTHBPForDriver.
229	HDCP related?
232	? Used in second_loader. DIP Switches 232, 240 and 241 are related.
236	GPU overclock. When enabled, GPU and GPU Xbar are overclocked from 111MHz to 166MHz.
237	On FW 0.990 (but not on FW 0.931 nor 3.60), this is the only DIP switch out of range 0-63 that can be set from usermode.
238	Underclock. When enabled, something is underclocked from 222MHz to 111MHz.
239	Underclock/overclock related.
240	? Used in second_loader. DIP Switches 232, 240 and 241 are related.
241	? Used in second_loader. DIP Switches 232, 240 and 241 are related.
250	Enable "tty0:"
251	Enable "dummytty0:"
252	? Used in SceSblFwLoader.

if ((System control flags & 1) != 0) { // not allow load QA flag } else { // allow load QA flag }

if ((System control flags & 2) != 0) { // clear qa flags // (SceQafMgrForDriver_382C71E8, SceQafMgrForDriver_52B4E164, sceSblQafMgrIsAllowHost0Access and sceSblQafMgrIsAllowDecryptedBootConfigLoad functions will return false) }

Hardware flags

Bit	Description
1	IC Connexant: 1 - yes, 2 - no
5	unk
6	unk
7	unk
14	unk

• all zeroes on most cases
• 47 02, 07 00 on a Slim

Types

typedef struct SceDIPSW {
  uint32_t cp_timestamp_1;
  uint16_t cp_version;
  uint16_t cp_build_id;
  uint32_t cp_timestamp_2;
  uint32_t aslr_seed;
  uint32_t sce_sdk_flags;
  uint32_t shell_flags;
  uint32_t debug_control_flags;
  uint32_t system_control_flags;
} SceDIPSW;

typedef struct SceKblParam {
  uint16_t version;
  uint16_t size;
  uint32_t current_fw_version;
  uint32_t min_fw_version;
  uint8_t unk_C[0x14];
  uint8_t qa_flags[0x10];
  uint8_t boot_flags[0x10];
  SceDIPSW dipsw;
  uint32_t dram_base;
  uint32_t dram_size;
  uint32_t unk_68;
  uint32_t boot_type_indicator_1;
  uint8_t openpsid[0x10];
  uint32_t secure_kernel_enp_addr;
  uint32_t secure_kernel_enp_size;
  uint32_t context_auth_sm_self_addr;
  uint32_t context_auth_sm_self_size;
  uint32_t kprx_auth_sm_self_addr;
  uint32_t kprx_auth_sm_self_size;
  uint32_t prog_rvk_srvk_addr;
  uint32_t prog_rvk_srvk_size;
  uint8_t pscode[8];
  uint8_t unk_A8[8];
  uint8_t session_id[0x10];
  uint32_t unk_C0;
  uint32_t wakeup_factor;
  uint32_t unk_C8;
  uint32_t unk_CC;
  uint32_t resume_context_addr;
  uint32_t hardware_info;
  uint32_t boot_type_indicator_2;
  uint8_t unk_DC[0xC];
  uint8_t hardware_flags[0x10];
  uint32_t bootldr_revision;
  uint32_t magic;
  uint8_t session_key[0x20];
  uint8_t unused[0xE0];
} __attribute__((packed)) SceKblParam;