Messages in this thread |  | | Date | Thu, 13 Dec 2012 15:38:24 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH v6 18/27] x86, boot: add fields to support load bzImage and ramdisk above 4G |
| |
On 12/13/2012 03:28 PM, Yinghai Lu wrote: > On Thu, Dec 13, 2012 at 2:54 PM, H. Peter Anvin <hpa@zytor.com> wrote: >> >> 0x1f0 is unsuitable for use as sentinel -- or in fact for any purpose -- >> because it is quite plausible that someone may (fairly sanely) start the >> copy range at 0x1f0 instead of 0x1f1... we really should have documented >> it that way but it is too late now. >> >> However, we can use 0x1ef. > > right. updated to use 0x1ef. >
> +1EF/001 ALL sentinel 0: states _ext_* fields are valid
Not the correct documentation. What this does is detect broken 32/64-bit bootloaders, and the remediation code should zero not just the ext_* fields but all the fields that were identified as uninitialized -- we're kind of assuming that kexec is representative here, since it doesn't help us by giving an ID.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
|  |