[U-Boot] Do we really need CONFIG_ARCH_CPU_INIT ?

Christian Riesch christian.riesch at omicron.at
Fri Mar 2 10:41:42 CET 2012

Hi again,

On Fri, Mar 2, 2012 at 9:46 AM, Christian Riesch
<christian.riesch at omicron.at> wrote:
> Hi,
> On Thu, Mar 1, 2012 at 9:48 PM, Albert ARIBAUD
> <albert.u.boot at aribaud.net> wrote:
>> Le 01/03/2012 14:23, Fabio Estevam a écrit :
>>> Hi,
>>> Currently CONFIG_ARCH_CPU_INIT is used to select arch_cpu_init() function.
>>> arch_cpu_init() does CPU level initialization, so why do we need to
>>> include CONFIG_ARCH_CPU_INIT in the include/configs/boardXYZ files,
>>> which are board related files ?
>>> For example:
>>> Let's say boards X, Y and Z are based on SoC S:
>>> 1. If processor S has a arch_cpu_init() defined, then it means that
>>> X,Y,Z need the code from arch_cpu_init() and then we need to define
>>> CONFIG_ARCH_CPU_INIT for each of these boards (actually all the boards
>>> based on this processor would need CONFIG_ARCH_CPU_INIT)
>>> 2. If not all boards need the code inside arch_cpu_init() for
>>> processor S, then it means that this code is not really CPU specific
>>> and then it should be moved to board code.
>> ... or some of these boards have a kind of preloader that does CPU level
>> inits before U-Boot is loaded, but other have not.
> Exactly. da850 based systems have several options to to lowlevel
> configuration, either in the AIS (a script interpreted by the ROM
> bootloader of the SoC), or by UBL (a user bootloader from Texas
> Instruments that does low level init and then loads u-boot) or by
> u-boot itself in arch_cpu_init(). Which way is used is board specific,
> but if the initialization is done by u-boot, the code is the same for
> all boards, it does not make sense to duplicate it.
> Boards that use the low level initialization in u-boot define
> CONFIG_ARCH_CPU_INIT, boards that rely on AIS or UBL do not define it.
> So if CONFIG_ARCH_CPU_INIT is removed, what should be done with da850
> based boards?
> Christian

Sorry, please forget what I wrote above. We already have a
CONFIG_DA850_LOWLEVEL option that already solves the problem. So
removing CONFIG_ARCH_CPU_INIT is fine for me.

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