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SubjectRe: [PATCH 0/6] Apple device properties
On Tue, 09 Aug, at 03:38:16PM, Lukas Wunner wrote:
> @@ -208,7 +201,10 @@ struct efi_config {
> __pure const struct efi_config *__efi_early(void);
>
> #define efi_call_early(f, ...) \
> - __efi_early()->call(__efi_early()->f, __VA_ARGS__);
> + __efi_early()->call(__efi_early()->is64 ? \
> + ((efi_boot_services_64_t *)__efi_early()->boot_services)->f : \
> + ((efi_boot_services_32_t *)__efi_early()->boot_services)->f, \
> + __VA_ARGS__);
>

You cannot use pointers from the firmware directly in mixed mode
because the kernel is compiled for 64-bits but the firmware is using
32-bit addresses, so dereferencing a pointer causes a 64-bit load.

That's the reason we deconstruct the tables and copy the addresses
from the last level - so we don't have to jump through multiple
pointers.

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