[PATCH v2 2/3] arm: Add [U]EFI runtime services support
From: Leif Lindholm <hidden>
Date: 2013-10-17 14:31:18
Also in:
linux-efi, lkml
On Thu, Oct 17, 2013 at 03:07:39PM +0100, Matt Fleming wrote:
quoted
+/* + * If you need to (temporarily) support buggy firmware. + */ +#define KEEP_BOOT_SERVICES_REGIONSHave you seen firmware that requires this? I'm just curious more than anything else.
Not really. I _think_ I saw it on a debug build of a development platform once. That coincided with me seeing a post on linux-efi about some laptop that broke unless boot services regions were preserved, so I decided to put it in there for any future debugging.
quoted
+/* + * Returns 1 if 'facility' is enabled, 0 otherwise. + */ +int efi_enabled(int facility) +{ + return test_bit(facility, &arm_efi_facility) != 0; +} +EXPORT_SYMBOL(efi_enabled);This should move to drivers/firmware/efi/efi.c. Let me write a patch that moves the x86 stuff out of arch/x86 and means you can get rid of this hunk.
Excellent, thanks!
quoted
+/* + * Called explicitly from init/mm.c + */That's init/main.c.
*cough*, right.
quoted hunk ↗ jump to hunk
quoted
+void __init efi_enter_virtual_mode(void) +{ + efi_status_t status; + + if (!efi_enabled(EFI_BOOT)) { + pr_info("EFI services will not be available.\n"); + return;This is dead code as PATCH 3 does,diff --git a/init/main.c b/init/main.c index af310af..ec6d76e 100644 --- a/init/main.c +++ b/init/main.c@@ -875,6 +875,10 @@ static noinline void __initkernel_init_freeable(void) smp_prepare_cpus(setup_max_cpus); do_pre_smp_initcalls(); + + if (IS_ENABLED(CONFIG_ARM) && efi_enabled(EFI_BOOT)) + efi_enter_virtual_mode(); +
True.
However, this call site is likely to change in the future (preferably
to an early_initcall), if we redesign the memory mapping to be reusable
after kexec(). At which point the test in efi_enter_virtual_mode() will
make sense again.
Could I change the test in init/main.c to do
if (IS_ENABLED(CONFIG_ARM) && IS_ENABLED(CONFIG_EFI))
instead?
/
Leif