History log of /freebsd-11-stable/sys/dev/efidev/efidev.c
Revision Date Author Comments
# 332028 04-Apr-2018 kevans

MFC r330868, r331241, r331361, r331365: EFIRT Fixes

r330868:
EFIRT: SetVirtualAddressMap with 1:1 mapping after exiting boot services

This fixes a problem encountered on the Lenovo Thinkpad X220/Yoga 11e where
runtime services would try to inexplicably jump to other parts of memory
where it shouldn't be when attempting to enumerate EFI vars, causing a
panic.

The virtual mapping is enabled by default and can be disabled by setting
efi_disable_vmap in loader.conf(5).

r331241:
Check if the gettime runtime service is valid.

The U-Boot efi runtime service expects us to set the address map before
calling any runtime services. It will then remap a few functions to their
runtime version. One of these is the gettime function. If we call into
this without having set a runtime map we get a page fault.

Add a check to see if this is valid in efi_init() so we don't try to use
the possibly invalid pointer.

r331361:
Enter into the EFI environment before dereferencing the runtime services
pointer. This may be within the EFI address space and not the FreeBSD
kernel address space.

r331365:
Re-work efidev ordering to fix efirt preloaded by loader on amd64

On amd64, efi_enter calls fpu_kern_enter(). This may not be called until
fpuinitstate has been invoked, resulting in a kernel panic with
efirt_load="YES" in loader.conf(5).

Move fpuinitstate a little earlier in SI_SUB_DRIVERS so that we can squeeze
efirt between it and efirtc at SI_SUB_DRIVERS, SI_ORDER_ANY. efidev must be
after efirt and doesn't really need to be at SI_SUB_DEVFS, so drop it at
SI_SUB_DRIVER, SI_ORDER_ANY.

The not immediately obvious dependency of fpuinitstate by efirt has been
noted in both places.


# 331021 15-Mar-2018 kevans

r322279: Don't create /dev/efi without EFI runtime

Turns out to be even simpler to just not create /dev/efi if we don't
have a efi runtime.


# 331019 15-Mar-2018 kevans

MFC r322278,324177: EFIRT Improvements

r322278 (imp): Fail to open efirt device when no EFI on system.

libefivar expects opening /dev/efi to indicate if the we can make efi
runtime calls. With a null routine, it was always succeeding leading
efi_variables_supported() to return the wrong value. Only succeed if
we have an efi_runtime table. Also, while I'm hear, out of an
abundance of caution, add a likely redundant check to make sure
efi_systbl is not NULL before dereferencing it. I know it can't be
NULL if efi_cfgtbl is non-NULL, but the compiler doesn't.

r324177 (andrew):
To prepare for adding EFI runtime services support on arm64 move the
machine independent parts of the existing code to a new file that can be
shared between amd64 and arm64.

Care has been taken to ensure that the MFC of r324177 did not clobber
cherry-picked MFC's.


# 318576 20-May-2017 kib

MFC efivar(8) (by imp):

List of revisions merged:
r307070
r307071
r307072
r307074
r307189
r307224
r307339
r307390
r307391
r309776
r314231
r314232
r314615
r314616
r314617
r314618
r314619
r314620
r314621
r314623
r314890
r314925
r314926
r314927
r314928
r315770
r315771

Discussed with: gjb (re), imp
Sponsored by: The FreeBSD Foundation