zephyr/arch/x86/core/intel64/tls.c

32 lines
656 B
C

/*
* Copyright (c) 2023 Intel Corporation.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel_internal.h>
FUNC_NO_STACK_PROTECTOR
void z_x86_early_tls_update_gdt(char *stack_ptr)
{
uintptr_t *self_ptr;
uint32_t fs_base = X86_FS_BASE;
/*
* Since we are populating things backwards, store
* the pointer to the TLS area at top of stack.
*/
stack_ptr -= sizeof(uintptr_t);
self_ptr = (void *)stack_ptr;
*self_ptr = POINTER_TO_UINT(stack_ptr);
__asm__ volatile(
"movl %0, %%ecx;\n\t"
"movq %1, %%rax;\n\t"
"movq %1, %%rdx;\n\t"
"shrq $32, %%rdx;\n\t"
"wrmsr;\n\t"
:
: "r"(fs_base), "r"(POINTER_TO_UINT(self_ptr)));
}