2010/3/15 Jamie Lokier <jamie@xxxxxxxxxxxxx>: > Marco Stornelli wrote: >> Il 13/03/2010 00:31, Jamie Lokier ha scritto: >> I agree, but the bootloader should be aware of it. I mean, usually >> bootloaders at boot, reset the RAM, so you have to tell to the >> bootloader that you are using a piece of RAM as persistent RAM, for >> example U-Boot has got a specific option CONFIG_PRAM. I don't know if >> all the process can be completely transparent to the admin in all >> situations. > > Sometimes you can't change the bootloader (they don't always come with > source code). Or you could, but you don't want to risk it (there > isn't always a way to recover if you break it). > > Obviously then the feature is only useful when the bootloader doesn't > clear all the RAM :-) > > On slow boards in consumer devices, they sometimes avoid clearing the > RAM because that adds measurable boot time. > In the embedded world, usually, you can change/write the fw and you know well the memory map, so no problem to know the address to use. In other cases, it can be possible to use a "transparent" approach, but in my opinion the general approach used by the driver is enough. Marco -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
