[U-Boot] BIOS EMULATOR driver

Graeme Russ graeme.russ at gmail.com
Wed Mar 28 00:56:21 CEST 2012


Hi Viktor,

On Wed, Mar 28, 2012 at 9:46 AM, Viktor Křivák <viktor.krivak at gmail.com> wrote:
> Dear Timur Tabi,
>
> 2012/3/27 Marek Vasut <marex at denx.de>:
>> Dear Timur Tabi,
>>
>>> Marek Vasut wrote:
>>> > Agreed, but I expected there was some dead code and that was the point I
>>> > was trying to express ;-)
>>>
>>> Well, until you do a thorough analysis, you really have no idea if there
>>> is any dead code at all.
>>
>> I don't ... but Viktor probably does and I believe that's what he wants to ask
>> about.
>
> Yes I do the analysis, actually only one method is used
> (PCI_mapBIOSImage), but there are two other methods related to video
> card. Booth in file drivers/bios_emulator/atibios.c (PCI_mapBIOSImage,
> PCI_unmapBIOSImage). Nothing calls they but I think they can be
> preserved too.
>
> But there are a lots of other code which can be removed. For example
> BE_mapRealPointer() from drivers/bios_emulator/biosemu.c or
> BE_getVESABuf() from same file. So my question is: It is safe remove
> dead code or somebody can use it for debugging purposes ? I've got
> same problem with another driver so this is general question.

What exactly is the problem?

Wolfgang previously pointed out:

"Did you check if you really find any such code in your linked image?
As I already explained, normally -ffunction-sections / -fdata-sections
with --gc-sections should make sure any unused functions get dropped
automatically."

If these linker options successfully remove all of the dead code, then
there should be no urgency in removing it. However, if you are
experiencing compile errors due to unused functions, then yes, removing
the dead code should be investigated. But if you plan to remove any
code, make sure that there are no other boards which may potentially use
the code you plan to remove

Regards,

Graeme


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