Downgrading with linux

You should have grafchokolos modules, and patches installed

This works on 3.55 without a fisical dongle

Use this method to install lower firmware! You can install a newer firmware ex 3.60 with this method but you will be loosing your hombrew

Thanks to graf_chokolo for bringing linux, with all this goodies back to the PS3

Downgrade Method - Emulating JIG with Linux

1st step – Generating a challenge

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1. ps3dm_usb_dongle_auth /dev/ps3dmproxy gen_challenge

2nd step – Generating a valid response for a challenge

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You need a dongle id. Valid range for dongle IDs is 0×0000 – 0xffff. So choose one, doesn’t matter which one, but some are revoked !!!

1. ps3dm_usb_dongle_auth /dev/ps3dmproxy gen_resp 0xBABE “here is a challenge like this 0xXX 0xXX … of size 20 bytes”

3rd step – Verifying response (Enabling “Product Mode”)

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1. ps3dm_usb_dongle_auth /dev/ps3dmproxy verify_resp 0xBABE

“here is the response from step 2 like this 0xXX 0xXX … of size 20 bytes”

4th step – Checking if “Product Mode” is enabled

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The returned value shouldn’t be 0xff.

1. ps3dm_um /dev/ps3dmproxy read_eprom 0x48C07

5th step - Inspect if CORE_OS_PACKAGE.pkg isn´t damaged

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ps3dm_um /dev/ps3dmproxy inspect_pkg 1 0x9 CORE_OS_PACKAGE.pkg

6th step - Install CORE_OS_PACKAGE.pkg

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ps3dm_um /dev/ps3dmproxy update_pkg 1 0x9 CORE_OS_PACKAGE.pkg

7th step – Disabling “Product Mode”

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1. ps3dm_um /dev/ps3dmproxy write_eprom 0x48C07 0xff

This step is really important, if Produc Mode isn´t disabled you will need a dongle to get out of it

ALTERNATIVE METHOD - not tested

1st step – Enabling product mode

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1. ps3dm_um /dev/ps3dmproxy write_eprom 0x48C07 0xfe

2th step – Checking if “Product Mode” is enabled

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The returned value shouldn’t be 0xff.

1. ps3dm_um /dev/ps3dmproxy read_eprom 0x48C07

3th step - Inspect if CORE_OS_PACKAGE.pkg isn´t damaged

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ps3dm_um /dev/ps3dmproxy inspect_pkg 1 0x9 CORE_OS_PACKAGE.pkg

4th step - Install CORE_OS_PACKAGE.pkg

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ps3dm_um /dev/ps3dmproxy update_pkg 1 0x9 CORE_OS_PACKAGE.pkg

5th step – Disabling “Product Mode”

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1. ps3dm_um /dev/ps3dmproxy write_eprom 0x48C07 0xff

This step is really important, if Produc Mode isn´t disabled you will need a dongle to get out of it

Install debug firmware

To install debug firmware, te proper syscon eeprom flags should be set http://www.ps3devwiki.com/index.php?title=Hypervisor_Reverse_Engineering#EEPROM_Offset_Table and EID0 should be resigned, reencrypted and rehashed with the proper target id

eEID contains

• system model data
• target ID
• PS3 motherboard revision