[lkml]   [2001]   [Aug]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: Encrypted Swap
    On Aug 17, 2001  11:51 -0700, Nicholas Knight wrote:
    > Now that we've established that SDRAM doesn't neccisarily get erased from
    > rebooting, does anyone know how long it takes for SDRAM to clear after
    > losing power? It seems to me that the fact that the RAM isn't neccisarily
    > wiped by the BIOS at boot is less important than wether or not shutting
    > down the system and having it shut down for 10 minutes causes the RAM to
    > be cleared so that any intruder/thief would be unable to get the
    > information neccisary to decrypt the swap...

    Hmm, it was my understanding that all PC BIOSes DO zero out memory,
    although this is not necessarily a requirement of the hardware. The
    reason I say this is because one of the features of the Linux BIOS
    project is to allow crashdump analysis after a reboot, by pulling
    the dump from the RAM after a reboot. You apparently are not able
    to do this with normal PC BIOSes because they clear the RAM after
    a reset.

    That said, I'm not sure what the requirements of different kinds of
    RAM chips are for initialization, so there may not be a REQUIREMENT
    to clear the memory, but rather it is part of the nebulous "PC spec".

    Cheers, Andreas
    Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto,
    \ would they cancel out, leaving him still hungry?" -- Dogbert

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 12:57    [W:0.023 / U:15.020 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site