Description

The ADSL PHY is a separate Mips System with its memory mapped into the host address space, but can also access the host's RAM. The ADSL PHY Firmwares can be used on any SoC with the same ADSL PHY Version.

ADSL PHY Version	DSL Standard	Used in SoC
A	ADSL2	BCM6345 (BCM6335?)
B	ADSL2+	BCM6338, BCM6348, BCM6358
C	ADSL2+, VDSL2	BCM6368
D	ADSL2+	BCM6328, BCM6362
F	ADSL2+, VDSL2	BCM63168

Memory Access

The adsl phy local memory is accessible at the following range:

chip	host	phy	size
BCM6338 BCM6345 BCM6348 BCM6358	`0xfff00000`	`0x19000000`	256k?
BCM6328 BCM6362	`0xb0d80000`	`0x19000000`	?
BCM6368	`0xb0f80000`	`0x19000000`	?
BCM63168	`0xb0780000`	`0x19000000`	?

To access the host's ram, the adsl phy maps a 2 MiB (BCM6345: 512KiB) block of ram containing the Firmware into its own address space at 0x10000000.

Adsl Phy Firmware

The Adsl Phy requires a separate firmware for the Adsl Mips core. It consists of two parts, a smaller one loaded into the memory of the Adsl Mips core, and a bigger one loaded into the uppermost part of the host system ram. There are separate firmwares for different annexes.

File Header

Each adsl_phy.bin has a 32 byte long header:

offset	size	usage	Notes
`0x00`	32 bit	header	always `0x41200000` ('A \0\0')
`0x04`	32 bit	lmemImageOffset	offset of the adsl mips part in the file
`0x08`	32 bit	lmemImageLen	length of the adsl mips part
`0x0c`	32 bit	sdramImageOffset	offset of the shared part in the file
`0x10`	32 bit	sdramImageLength	length of the shared part
`0x14` - `0x1f`		???	seems to be always zero.

Communicating with the Phy

The adsl phy provides an interface for sending and receiving messages. All pointers are assumed to be phy local, not host local, so need to be converted when accessing. The interface is located at the following offset in the LMEM:

chip	offset
BCM6345	`0x17f90`
BCM6338 BCM6348 BCM6358 BCM6328 BCM6362	`0x21f90`
BCM6368 BCM63168	`0x5ff90`

Interface Layout

offset	size	usage	Notes
`0x00`	6 * 32 bit	Status Buffer Pointers	used for receiving status updates
`0x18`	6 * 32 bit	Command Buffer Pointers	used for sending commands
`0x30`	15 * 32 bit	GFC Table
`0x6c`	32 bit	Sdram Base	points to the beginning of the reserved RAM in KSEG1

Buffer Pointer Layout

All pointers are 32 bit big and in Adsl Phy address space.

offset	usage	Notes
`0x00`	start	start of the buffer
`0x04`	end	end of the regular buffer
`0x08`	extra end	end of the additional buffer space
`0x0c`	stretch end	current usage of the additional buffer space
`0x10`	read	current read pointer
`0x14`	write	current write pointer

Messages

All Messages exchanged are aligned to 4 byte (filled to a multiple of 4 if necessary), and are followed by the sequence 0x55aa1234. All messages are at least 8 byte long, excluding the magic value at the end. Essentially it is:

<MessageType>

<Content>+

0x55aa1234

Checking for available Messages

if (write >= read)
- (write - read) bytes available
else
- (stretch end - read) bytes available

Receiving Messages

read message until magic value was read
if (new read position >= stretch end)
- reset read to start
else
- set read to new read position

Sending Messages

check for available space
write message
write magic value
if (new write position >= end)
- if (read != start)
  - set stretch end to new write position
  - set write to start
else
- set write to new write position

See PhyMessages for all known messages.