Syscon Update

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Structure

Ernie firmware updates are stored in a packet format.

Packet Header

Any Syscon firmware update packet has a common 4-byte header structure.

Offset Size Description
0x0 0x1 Type (ex: 1, 2, 3, 0x10, 0x20)
0x1 0x1 Data offset (ex: 0x10, 0x18)
0x2 0x2 Data size (ex: 0, 0x20, 0x400, 0x800)

Data size varies with the packet type and also with the hardware revision of Syscon: 

Renesas 78K0R/Kx3: 0x800
Renesas 78K0R/Kx3-L: 0x400
Renesas RL78/G13: 0x400

Packet Types

0x01

Version packet.

This packet is update SPKG header field.

Offset Size Description
0x0 0x4 Packet Header
0x4 0x4 Firmware Version. Version of the Ernie software update. (ex: 0x0100060B -> 1.0.6.11)
0x8 0x4 Hardware Info. PS Vita hardware on which this update can be installed. (ex: 0x00723030)
0xC 0x4 Padding

Ernie Version and Hardware Info from a few PUP files: 

1.80 CEX
0B 06 00 01 00 32 60 00
0B 06 00 01 00 30 60 00
0B 06 00 01 00 20 60 00
0B 06 00 01 00 10 60 00
0B 06 00 01 00 60 40 00

1.81 CEX
0B 06 00 01 00 32 60 00
0B 06 00 01 00 30 60 00
0B 06 00 01 00 20 60 00
0B 06 00 01 00 10 60 00
0B 06 00 01 00 60 40 00

3.15 CEX
11 05 03 01 38 50 80 00
03 06 03 01 30 30 70 00
0D 06 00 01 00 32 60 00
0D 06 00 01 00 30 60 00
0D 06 00 01 00 20 60 00
0B 06 00 01 00 10 60 00
0D 06 00 01 00 60 40 00

3.30 CEX
11 05 03 01 38 50 80 00
01 03 04 01 30 30 72 00
03 06 03 01 30 30 70 00
0D 06 00 01 00 32 60 00
0D 06 00 01 00 30 60 00
0D 06 00 01 00 20 60 00
0B 06 00 01 00 10 60 00
0D 06 00 01 00 60 40 00

1.69 TOOL
06 03 00 01 00 40 41 00
06 03 00 01 00 50 41 00
03 02 09 00 00 50 31 00
06 03 00 01 00 10 41 00
06 03 00 01 00 52 41 00
06 03 00 01 03 26 10 00
06 03 00 01 00 52 31 00

1.80 TOOL
0B 06 00 01 00 10 60 00
0B 06 00 01 00 60 41 00
0B 06 00 01 00 52 41 00
06 03 00 01 03 26 10 00

0x02

Key revision packet.

This packet embeds the encryption key revision used to decrypt the Syscon update packets.

Offset Size Description
0x0 0x4 Packet Header
0x4 0x4 Image Size (ex: 0)
0x8 0x4 Firmware Type (ex: 0, 1, 2)
0xC 0x4 Padding
  • Firmware Type 0 is for NEC 78K0R/Kx3-L. It is supported since at least System Software version 0.931.010 (System Software version 0.902 does not support it) til System Software version 1.692.000. It is for some PS Vita prototypes.
  • Firmware Type 1 is for NEC 78K0R/Kx3. It is supported since System Software version 1.000.041. It is for most PS Vita Fat models and for PS TV.
  • Firmware Type 2 is for Renesas RL78/G13. It is supported since System Software version 2.500.071. It is for PS Vita Slim Syscon.

0x03

Signature packet.

This packet is special because it is not embedded in Syscon Update SPKGs. It is sent to Syscon using SceSyscon#sceSysconUpdaterCheckSignatureForDriver.

It is not supported on FWs 0.931.010-0.940 but supported on 0.996.090-3.740.011.

Steps:

  • sceSysconUpdaterCheckSignatureForDriver(signature, 0x18);
  • sceSysconUpdaterSetRunModeForDriver(runMode);
Offset Size Description
0x0 0x4 Packet Header
0x4 0x18 Signature
0x1C 0x4 Padding

0x10

Segment packet.

Segment packet is broken into chunks before being sent. Chunks are concatenated before being AES128CBC encrypted/decrypted.

Steps:

  • sceSysconUpdaterCalcChecksum(data, size, &checksum); // compute segment checksum
  • sceSysconUpdaterSetSegment(segment_no); // send segment number
  • If Ernie DL version <= 0x1700, max_chunk_size = 0x10 else max_chunk_size = 0x40.
  • For each chunk, SendProgramData(data, offset, chunk_size & 0xff); // send segment by chunks
  • sceSysconUpdaterExecProgramming(checksum); // send segment checksum
Offset Size Description
0x0 0x4 Packet Header
0x4 0x4 Segment Number. Must be between 0 and 0x17F.
0x8 0x4 Size (ex: 0x400 for Renesas RL78/G13 and NEC 78K0R/Kx3, 0x800 for NEC 78K0R/Kx3-L)
0xC 0x4 Padding
0x10 Variable Encrypted data

0x20

Checksum packet.

Checksum is sent from ARM to Syscon using SceSyscon#sceSysconUpdaterExecFinalizeForDriver.

Steps:

  • sceSysconUpdaterExecFinalize(checksum, 0x14);
Offset Size Description
0x0 0x4 Packet Header
0x4 0x14 Checksum. Sha-1 hash of decrypted concatenated segments.

Ernie Updater Run Modes

Runmode Supported System Software version Context Comments
0x9a54 0.931.010-3.740.011 SPKG Type 8 -> runModeFlag = 0 After setting this runMode, you need to execute handshake if (ernie_DL_version & 0xffffff) >= 0x3600.
0x72ba 0.931.010-3.740.011 ?runModeFlag = 1? This Run Mode is set after not before executing sceSysconUpdater functions.
0x3665 0.996.090-3.740.011 SPKG Type 0x14 -> runModeFlag = 2
0xc5e7 0.996.090-3.740.011 SPKG Type 0x19 -> runModeFlag = 3
0x152e 3.600.011-3.740.011 unknown Seen in Ernie firmware shipped with System Software version 3.600.011 but not in ARM update_mgr.skprx.

Remarks

On ARM update_mgr.skprx shipped with System Software version 0.996.090:

  • Only run mode 0x9a54 is used as only SPKG Type 8 is supported concerning Syscon firmware update.

On ARM update_mgr.skprx shipped with System Software version 3.60:

  • runModeFlag can be 0, 2 or 3. runModeFlag is checked for value 1 but this value 1 is never set.

On Ernie firmware shipped with System Software version 3.60:

  • Only updater run mode 0x72BA seems to be actually useful.
  • Modes 0x9A54 and 0x152E are recognized but just make the function return without doing anything.
  • Mode 0xC5E7 is not recognized by Ernie firmware shipped with System Software version 3.60, although it is present on ARM side.

Ernie Update steps

  • ARM PS Vita updater arrives at last step: Ernie update.
  • ARM PS Vita updater decrypts Ernie update SPKGs til it finds one whose Hardware Info matches.
  • ARM PS Vita updater sends run mode 0x9a54 to Ernie using Syscon command 0x1183 (sceSysconUpdaterSetRunModeForDriver).
  • If (ernie_DL_version & 0xffffff) >= 0x3600, a handshake is done using Syscon command 0xD0 (SceSysconForDriver_4D03754A) through update_service_sm function 0xD0002.
  • ARM PS Vita updater sends if needed a new run mode to Ernie using Syscon command 0x1183 (sceSysconUpdaterSetRunModeForDriver).
  • ARM PS Vita updater computes sha1 checksum over the decrypted concatenated data (sceSysconUpdaterCalcChecksumForDriver).
  • ARM PS Vita updater sends the encrypted segment number directly to Ernie using Syscon command 0x1180 (sceSysconUpdaterSetSegmentForDriver).
  • ARM PS Vita updater sends the encrypted segment chunks directly to Ernie using Syscon command 0x1181 (sceSysconUpdaterSendProgramDataForDriver / sceSysconUpdaterSendProgramData2ForDriver).
  • ARM PS Vita updater sends the segment checksum directly to Ernie using Syscon command 0x1182 (sceSysconUpdaterExecFinalizeForDriver).
  • ARM PS Vita updater sends the total checksum directly to Ernie using Syscon command 0x1184 (sceSysconUpdaterExecFinalizeForDriver).
  • Ernie decrypts concatenated received segments using AES128CBC.
  • Ernie computes sha1 checksum over the decrypted concatenated data and compares with the received checksum.
  • Ernie installs the update using the decrypted data.
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