Re: Dreamcast AICA driver

[James Courtier-Dutton <James@superbug.co.uk>]

Adrian McMenamin wrote:
> I know what these are - they can be turned into constants - they are
> either references to the ARM7 register bank or the ARM7 memory space.
>
>
>   
>> It looks like many of these will be trivial to document:
>>
>> 	if (request_mem_region(0xa0702c00, 4, "AICA ARM control")== NULL) return -ENOMEM;
>> 	if (request_mem_region(0xa0800000, 0x200000, "AICA Sound RAM") == NULL)
>>
>> Lee
>>
>>     

Adrian,

It was good to talk to you on IRC. Now, as you have the source code for 
the ARM7 firmware as well as the SH4 driver code, it might be sensible 
to highlight the dependencies between them, by maybe using the same 
human readable constant name in both bits of code. It also makes things 
easier to understand if the hex addresses are given as offsets from some 
sort of base.

if (request_mem_region(0xa0702c00, 4, "AICA ARM control")== NULL) return -ENOMEM;

then becomes in a .h file:
#define ARM7_BASE_MEM  0xa0700000
#define ARM7_AICA_CONTROL  0x2c00

During driver init:
base_mem = ARM7_BASE_MEM

if (request_mem_region(base_mem + ARM7_AICA_CONTROL, 4, "AICA ARM control")== NULL) return -ENOMEM;

This would then allow movement of the base_mem without much modification to the driver code, if for example the ARM7 firmware required the change.

James



-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting language
that extends applications into web and mobile media. Attend the live webcast
and join the prime developer group breaking into this new coding territory!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642