robin.thoni/ipxe - git rthoni.com

Michael Brown cc9f31ee0c [librm] Do not unconditionally preserve flags across virt_call() Commit 196f0f2 ("[librm] Convert prot_call() to a real-mode near call") introduced a regression in which any deliberate modification to the low 16 bits of the CPU flags (in struct i386_all_regs) would be overwritten with the original flags value at the time of entry to prot_call(). The regression arose because the alignment requirements of the protected-mode stack necessitated the insertion of two bytes of padding immediately below the prot_call() return address. The solution chosen was to extend the existing "pushfl / popfl" pair to "pushfw;pushfl / popfl;popfw". The extra "pushfw / popfw" appears at first glance to be a no-op, but fails to take into account the fact that the flags restored by popfl may have been deliberately modified by the protected-mode function. Fix by replacing "pushfw / popfw" with "pushw %ss / popw %ss". While %ss does appear within struct i386_all_regs, any modification to the stored value has always been ignored by prot_call() anyway. The most visible symptom of this regression was that SAN booting would fail since every INT 13 call would be chained to the original INT 13 vector. Reported-by: Vishvananda Ishaya <vishvananda@gmail.com> Reported-by: Jamie Thompson <forum.ipxe@jamie-thompson.co.uk> Signed-off-by: Michael Brown <mcb30@ipxe.org>		vor 8 Jahren
contrib	[errdb] Strip platform error code for non-platform-generated errors	vor 11 Jahren
src	[librm] Do not unconditionally preserve flags across virt_call()	vor 8 Jahren
COPYING	[legal] Update GPLv2 licence text	vor 10 Jahren
COPYING.GPLv2	[legal] Update GPLv2 licence text	vor 10 Jahren
COPYING.UBDL	[legal] Add support for the Unmodified Binary Distribution Licence	vor 10 Jahren
README	[doc] Re-add README file	vor 14 Jahren

iPXE README File

Quick start guide:

   cd src
   make

For any more detailed instructions, see http://ipxe.org