Making Isolated SPU Modules and Loaders

Introduction

• E.g. to dump your ATA, ENCDEC or EID2 keys you have to make signed isolated SPU modules or loaders.
• This is a tutorial how to do it on Linux (it doesn't matter on PC or PS3).

Tools

SPU GCC Compiler

• You need SPU GCC compiler to compile your code and create binary version of it.
• On PS3 Debian, just install spu toolchain.
• You can also cross-compile SPU GCC toolchain for your Linux PC.
• See http://gitorious.ps3dev.net/ps3linux/powerpc64-cross-compiler if you want to build SPU GCC cross-compiler. Just change in HOWTO target option from powerpc64-linux to spu-elf.

ps3tools

• You need these tools to decrypt PS3 isolated SPU modules and loaders.
• You also need it to sign and encrypt your own SPU modules and loaders.
• self_rebuilder doesn't work properly with isolated SPU modules or loaders. Therefore, i made a new tool which works with isolated SPU modules and loaders. It's called iso_rebuilder and is a modified version of self_rebuilder.
• See my GIT repop: http://gitorious.ps3dev.net/ps3otheros/ps3tools

How To Test Isolated SPU Modules and Loaders

• I test my isolated SPU modules and loaders with PS3 Linux and spuisofs/spuldrfs Virtual File Systems.

spuisofs

• You can test with spuisofs isolated SPU modules which are decrypted by isoldr.
• You cannot test loaders with spuisofs.
• But spuisofs has the advantage that it's alot easier to execute isolated SPUs with it than with spuldrfs.

See http://www.ps3devwiki.com/wiki/Spuisofs

spuldrfs

• You can test with spuldrfs isolated SPU modules which are decrypted by isoldr and loaders which are decrypted by metldr.
• Use spuisofs if you want to execute isoldr SPUs, it's easier to do than with spuldrfs.

See http://www.ps3devwiki.com/wiki/Spuldrfs

Example: Making dump_ata_keys.self

• First you need sb_iso_spu_module.self from your NOR/NAND flash or from PS3 update file.

# compile your SPU code

spu-elf-gcc -c dump_ata_keys.S

ls -l dump_ata_keys.o

# convert your code to binary

spu-elf-objcopy -O binary dump_ata_keys.o dump_ata_keys.bin

ls -l dump_ata_keys.bin

# decrypt sb_iso_spu_module.self

unself sb_iso_spu_module.self sb_iso_spu_module.elf

ls -l sb_iso_spu_module.elf
mv sb_iso_spu_module.elf dump_ata_keys.elf

# print program header of decrypted SPU module

readelf -l dump_ata_keys.elf

Elf file type is EXEC (Executable file)
Entry point 0x880
There are 3 program headers, starting at offset 52

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  LOAD           0x000100 0x00000880 0x00000880 0x05040 0x05040 R E 0x80
  LOAD           0x005180 0x00005900 0x00005900 0x00030 0x001c0 RW  0x80
  NOTE           0x0051b0 0x00000000 0x00000000 0x00034 0x00000 R   0x10

 Section to Segment mapping:
  Segment Sections...
   00     .unknown .unknown 
   01     .unknown .unknown .unknown .unknown 
   02     .unknown 

# entry point is 0x880 which is in first program segment at file offset 0x100

# now we kill all old code with 0s before we put our code there.
# seek parameter is the offset of the first program segment.
# count parameter is the sum of the offset of the last program segment plus its size and
# minus the offset of the first program segmnet.

dd if=/dev/zero of=dump_ata_keys.elf bs=1 seek=$((0x100)) count=$((0x51b0 + 0x34 - 0x100)) conv=notrunc

# after you filled out the SPU module with 0s, check it with spu-objdump

spu-elf-objdump -d dump_ata_keys.elf 

dump_ata_keys.elf:     file format elf32-spu


Disassembly of section :

00000880 <>:
	...

# now we copy our code to SPU module
# seek parameter is the entry point offset in file

dd if=dump_ata_keys.bin of=dump_ata_keys.elf bs=1 seek=$((0x100)) conv=notrunc

# now build isolated SPU module

iso_rebuilder dump_ata_keys.elf dump_ata_keys.self sb_iso_spu_module.self

# we are done :)
# time to test it with spuisofs !!!

Example: Making dump_encdec_keys.self

• First you need lv1ldr from your NOR/NAND flash or from PS3 update file.