u-boot/arch/x86/include/asm/processor.h

/*
 * (C) Copyright 2002
 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef __ASM_PROCESSOR_H_
#define __ASM_PROCESSOR_H_ 1

#define X86_GDT_ENTRY_SIZE	8

#ifndef __ASSEMBLY__

enum {
	X86_GDT_ENTRY_NULL = 0,
	X86_GDT_ENTRY_UNUSED,
	X86_GDT_ENTRY_32BIT_CS,
	X86_GDT_ENTRY_32BIT_DS,
	X86_GDT_ENTRY_32BIT_FS,
	X86_GDT_ENTRY_16BIT_CS,
	X86_GDT_ENTRY_16BIT_DS,
	X86_GDT_NUM_ENTRIES
};
#else
/* NOTE: If the above enum is modified, this define must be checked */
#define X86_GDT_ENTRY_32BIT_DS	3
#define X86_GDT_NUM_ENTRIES	7
#endif

#define X86_GDT_SIZE		(X86_GDT_NUM_ENTRIES * X86_GDT_ENTRY_SIZE)

#ifndef __ASSEMBLY__

static inline __attribute__((always_inline)) void cpu_hlt(void)
{
	asm("hlt");
}

static inline ulong cpu_get_sp(void)
{
	ulong result;

	asm volatile(
		"mov %%esp, %%eax"
		: "=a" (result));
	return result;
}

#endif /* __ASSEMBLY__ */

#endif