linux-kernel - Re: [PATCH 4/9] ARM: add CONFIG_PHYS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.LFD.2.20.1602191106020.13632@knanqh.ubzr>
Date:	Fri, 19 Feb 2016 11:10:22 -0500 (EST)
From:	Nicolas Pitre <nicolas.pitre@...aro.org>
To:	Arnd Bergmann <arnd@...db.de>
cc:	Russell King <linux@....linux.org.uk>,
	linux-arm-kernel@...ts.infradead.org,
	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	Jon Medhurst <tixy@...aro.org>,
	Marc Zyngier <marc.zyngier@....com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/9] ARM: add CONFIG_PHYS_OFFSET default values

On Fri, 19 Feb 2016, Arnd Bergmann wrote:

> On Thursday 18 February 2016 11:02:33 Nicolas Pitre wrote:
> > 
> > Acked-by: Nicolas Pitre <nico@...aro.org>
> > 
> > Is there a way to provide a default for defaults?
> 
> We could have something like
> 
> config PHYS_OFFSET_0
> 	bool
> 
> config PHYS_OFFSET_1
> 	bool
> 
> config PHYS_OFFSET_2
> 	bool
> 
> ... (we need 8 of the 16 possible addresses)
> 
> 
> config PHYS_OFFSET
> 	hex "Physical address of main memory" if MMU
> 	default DRAM_BASE if !MMU
> 	default 0x00000000 if PHYS_OFFSET_0
> 	default 0x10000000 if PHYS_OFFSET_1
> 	default 0x20000000 if PHYS_OFFSET_2
> 	default 0x30000000 if PHYS_OFFSET_3
> 	default 0x70000000 if PHYS_OFFSET_7
> 	default 0x80000000 if PHYS_OFFSET_8
> 	default 0xa0000000 if PHYS_OFFSET_A
> 	default 0xc0000000 if PHYS_OFFSET_C
> 
> 
> and then select one of the bool symbols from each platform.
> Would that address your question?

Yes, but the ugliness factor isn't worth it IMHO.

I was wondering if something like this was possible:

config PHYS_OFFSET
        hex "Physical address of main memory" if MMU
        default DRAM_BASE if !MMU
        default 0x10000000 if FOO
        default 0x20000000 if BAR
        default 0x30000000 if BAZ
        default 0x00000000


Nicolas