7/29/2019 CellBEBootprocess(1)

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Power OnEvent

lv0ldr(Bootloader)

CellBE

Configuration Ring(CPU init settings)

Lv0 (SE Bootloader)

metldr(Meta Loader)

lv1ldr

lv2ldr

appldr

isoldr

Lv1 (Hypervisor)

Lv2 (GameOS)

SysCon (System Controller)

wer On Reset Sequence (POR)

t Sequence

ervisor Init

nel Init

Metldr is loaded to an isolated SPU tofacilitate loading of each SPU IsolatedLoader.ref. IBM Secure SDK Documentation

Lv0 is decrypted to the PPU RAM bylv0ldr. Lv0ldr then starts the PPUexecuting Lv0 from RAM at address0x100. There is no extra loader used on

the SPU in this case.

cation OffsetND: 0x0R: 0xFC0000

SPU loads and executes lv0ldr according tothe reset vector provided. This differs to theprocess in non secure boot, where theROM code is executed by PPUref. CellBE HIG - 2.2.1

Loads configuration ring and calibrates I/Ocontroller, will not do anything further inPORref. CellBE HIG - 2.2

This contains the reset vector, which is theaddress of lv0ldr. It also contains the initialregister and cpu settings, these are passedto the CellBE

ref. CellBE HIG - 2.3.4

set Vector for secure bootND: 0x240_1FC00000R: 0x240_1FFC0000

Time

metldr

(Meta Loader)

SPU SecureLoader

SPUIsolatedLoader

PPCSecure ELF (SELF)

Hardware

CellBE Secure Boot Process

1 by mas & xorloser

HW Root Key

HW Root Key

HW Root Key

From now on access to hardwareresources must be done via theHypervisor. Direct access is no longerpossible.

GameSystem Files

Isolated SPU Modules(i.e.sc_iso.self)

SPUSecure ELF (SELF)

rland Init

ated SPU Init metldr(Meta Loader)

metldr(Meta Loader)

HW Root Key

HW Root Key

SPU Isolated Loaders are loaded by metldrto a high LS address. Metldr then zeros

itself out and jumps to their entrypoint tobegin their execution.

Isolated SPU Modules are loaded by isoldrto a low LS address. Isoldr then zeros itselfout and jumps to their entrypoint to begintheir execution.

Loading a game is optional

System files like vsh (XMB) or games callback to the GameOS, which then call backto the hypervisor for certain operations. Theprocesses in userland after boot are moredynamic, but this is outside the scope of thisdocument.

Vsh(XMB)

HW Root Key is storede the CellBE hardware.key is unique to each

BE and is used to decryptverify SPU Secure Loaders

h as metldr and lv0ldr

SPU Secure Loaders are loaded by CellBEhardware to the LS address 0x400. TheCellBE decrypts, authenticates and thenexeutes them at 0x400.

The Game Operating System kernel runson top of the hypervisor. Both this kerneland the hypervisor stay present in memorywhile all userland operations run on top ofthem.

Legend