Southbridge
PS4 southbridge contains two processors named EMC and EAP on the same die that are mainly used on boot, during rest mode and for servicing.
Components
Southbridge processors
The two processors are on the same die. It is a SoC (System on Chip).
EMC
EMC could stand for External Micro Controller. EMC was named MediaCon by some people when its name was still unknown.
The role of EMC is to load EMC IPL and EAP kernel, to be an interface for icc for the main APU kernel and Syscon and to offer a debug interface via UART that does not rely on Syscon or main APU. EMC runs its own FreeBSD kernel. It is a Marvell Armada, an ARM-based SoC. Sony stuck a PCIe bridge on it. It exposes ARM peripherals to the x86 side. There is some extra stuff (e.g. HPET, ACPI stuff).
EMC cpuid = 412FC231 (ARM Cortex-M3 r2p1). CPU clock: maybe about 100MHz.
EAP
EAP could stand for External Application Processor.
The role of EAP is to handle media (online Wireless/GbLAN, Bluray Drive and Harddrive) even in standby mode. EAP runs its own FreeBSD kernel in standby mode, activated to handle tasks such as downloading updates while the PS4 is in standby.
It handles several tasks to offload the APU:
- Network connections: Wireless and GbLAN, including background downloading and PlayGo
- File handling (Bluray Drive, Harddrive and USB 3.0), including background caching
- Main serial flash handling
EAP consists of Marvell PJ4C B0 rev 1 cores, ARMv7 CORTEX-A8 running FreeBSD 9 kernel. CPU clock: 500MHz. DDR clock: 800MHz.
As EAP Core software is unsigned, unencrypted and easily replaceable on PS4 HDD with a PS4 kernel exploit, it is possible to run homebrew code on EAP processor. See eapdev by Bigboss (psxdev).
Southbridge RAM
Southbridge chip is connected to its own DDR3 SDRAM. It is named "sbram" as in SouthBridge RAM.
PS4 Fat and Slim
PS4 Fat and Slim Southbridge has one Samsung K4B2G1646E-BCK0, K4B2G1646F-BCMA or K4B2G1646Q-BCMA, giving a total of 256MB of memory.
PS4 Pro
PS4 Pro Southbridge has two Samsung K4B4G0846E-BYMA or H5TQ4G83CFR-RDC (K4B4G1646E-BYK0 on PS4 Pro DevKit), giving a total of 1GB of memory.
Serial Flash
Southbridge contains a 256MB Serial flash.
Aeolia has Macronix MX25L25635FMI-10G.
Auxiliary components
Southbridge is connected to the main APU by PCI-Express x4 and to Syscon by SPI.
Aeolia has SATA bridge MB86C311B, GbLAN controller 88EC060-NN82.
Southbridge revisions
There are three major hardware revisions, named Aeolia, Belize and Baikal.
See also Aeolia.
Southbridge revisions per chassis
Model (chassis) | Motherboards | Southbridge Codename | Southbridge Labeling |
---|---|---|---|
D1000 | All CVN | Aeolia | CXD90025G |
1000 | All SAA | Aeolia | CXD90025G |
1100 | All SAB | Aeolia | CXD90025G |
1200 | All SAC | Belize | CXD90036G |
2000 | All SAD | Belize | CXD90036G |
D7000 | All HAC | Belize | CXD90036G |
2100 | Some SAE | Belize 2 | CXD90046GG |
7000 | All NVA | Belize 2 | CXD90046GG |
2200 | Some SAE, all SAF | Baikal | CXD90042GG |
7100 | All NVB | Baikal | CXD90042GG |
7200 | All NVG | Baikal | CXD90042GG |
Motherboards per southbridge revisions
Southbridge Codename | Southbridge Labeling | Motherboards |
---|---|---|
Aeolia | CXD90025G |
CVN-K12 |
Belize | CXD90036G |
HAC-001 |
Belize 2 | CXD90046GG |
NVA-001 |
Baikal | CXD90042GG |
NVB-004 |
|