Hi Wolfgang,
On 15/12/12 09:26, Wolfgang Denk wrote:
Dear Tom Rini,
In message 50CB8ED1.7020503@ti.com you wrote:
The other part is, take a look at the Allwinner thread from a week or so ago. We really need to define how we want early board specific data to come in because if we start saying we'll accept per-SoC solutions we'll be drowning in them in short time. We want to say here's our preferred way to pass this information in.
ACK!
And we already have a well-defined way to do this, which is the device tree. So any attempts to implement something different should be reviewed very carefully.
I'm not sure I 100% get this, but from what I understand, the SoC (or maybe even some EEPROM on a particular board family) may contain device enumeration data in some vendor specific format (i.e. not in a device tree compatible format).
The way I see it, there is no way that U-Boot can dictate to SoC and board vendors and say that data must be stored in DT format. So shouldn't U-Boot instead implement a board/SoC specific translation layer which converts this custom data into DT format (maybe in SPL if possible)?
But the other problem is if this data includes console specific information (UART configuration). We are left blind until the DT functions become available. So maybe we need some small standard interface to allow the console to be configured early. But we need to prevent this from being abused (i.e. being used to do all kinds of hardware setting from the raw data and bypassing DT)
Am I understanding this right?
Regards,
Graeme