In message <200805282201.48746.rob@xxxxxxxxxxx> you wrote: > > The standard way of doing this is to use the mem= kernel command line > parameter to tell the system it has less memory than it does, and using > what's left as a ramdisk. Years ago I saw some userspace thing running as > root mmap() /dev/mem (or whatever they're calling it these days) and log to > it. In theory you could even set the dmesg buffer up at the end of physical > memory with a smallish kernel patch, make it big, and set the kernel to doing > verbose printks. That's not theory, but a standard feature in U-Boot. It's called shared log buffer, as U-Boot can also use this buffer for example for POST results. > The trick is A) knowing the absolute physical address at which your debug > buffer lives so you can find it after the reboot, B) convincing the system to > do something useful with it on reboot rather than just overwriting it with > fresh log data. There is no trickery involved. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@xxxxxxx My brother sent me a postcard the other day with this big sattelite photo of the entire earth on it. On the back it said: "Wish you were here". - Steven Wright -- 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
