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Re: Modpost warning on Alchemy

To: Sergei Shtylyov <>
Subject: Re: Modpost warning on Alchemy
From: "Maciej W. Rozycki" <>
Date: Thu, 2 Aug 2007 15:33:11 +0100 (BST)
Cc: Ralf Baechle <>,
In-reply-to: <>
Original-recipient: rfc822;
References: <> <> <> <> <> <> <> <> <> <> <> <> <> <> <>
On Thu, 2 Aug 2007, Sergei Shtylyov wrote:

>    Yeah, that the format of type 1 cycles.

 Well, that is how it is presented to software on many systems.  The type 
1 cycle format actually differs a little bit, as the two least significant 
bits of the register number are passed to byte enables and when presented 
to the bus they are replaced with a fixed code that denotes the cycle 

>    Unfortunately, Alchemy designers were too lazy to implement a simple
> translation scheme for type 0 cycles. They probably though that with 36-bit
> bus the may not limit themselves... :-)

 Yes, some people seem to think the abundance of resources exempts them 
from properly architecting their designs, sigh...

 On the other hand, the decision to identity-map the PCI config space in 
the physical address space of the processor rather than only making it 
accessible through a pair of an address and a data register was good IMO.


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