path: root/arch/x86/kernel/setup.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 1995  Linus Torvalds
 *
 * This file contains the setup_arch() code, which handles the architecture-dependent
 * parts of early kernel initialization.
 */
#include <linux/console.h>
#include <linux/crash_dump.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/init_ohci1394_dma.h>
#include <linux/initrd.h>
#include <linux/iscsi_ibft.h>
#include <linux/memblock.h>
#include <linux/pci.h>
#include <linux/root_dev.h>
#include <linux/sfi.h>
#include <linux/tboot.h>
#include <linux/usb/xhci-dbgp.h>

#include <uapi/linux/mount.h>

#include <xen/xen.h>

#include <asm/apic.h>
#include <asm/bios_ebda.h>
#include <asm/bugs.h>
#include <asm/cpu.h>
#include <asm/efi.h>
#include <asm/gart.h>
#include <asm/hypervisor.h>
#include <asm/io_apic.h>
#include <asm/kasan.h>
#include <asm/kaslr.h>
#include <asm/mce.h>
#include <asm/mtrr.h>
#include <asm/olpc_ofw.h>
#include <asm/pci-direct.h>
#include <asm/prom.h>
#include <asm/proto.h>
#include <asm/unwind.h>
#include <asm/vsyscall.h>

/*
 * max_low_pfn_mapped: highest directly mapped pfn < 4 GB
 * max_pfn_mapped:     highest directly mapped pfn > 4 GB
 *
 * The direct mapping only covers E820_TYPE_RAM regions, so the ranges and gaps are
 * represented by pfn_mapped[].
 */
unsigned long max_low_pfn_mapped;
unsigned long max_pfn_mapped;

#ifdef CONFIG_DMI
RESERVE_BRK(dmi_alloc, 65536);
#endif


/*
 * Range of the BSS area. The size of the BSS area is determined
 * at link time, with RESERVE_BRK*() facility reserving additional
 * chunks.
 */
static __initdata
unsigned long _brk_start = (unsigned long)__brk_base;
unsigned long _brk_end   = (unsigned long)__brk_base;

struct boot_params boot_params;

/*
 * These are the four main kernel memory regions, we put them into
 * the resource tree so that kdump tools and other debugging tools
 * recover it:
 */

static struct resource rodata_resource = {
	.name	= "Kernel rodata",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};

static struct resource data_resource = {
	.name	= "Kernel data",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};

static struct resource code_resource = {
	.name	= "Kernel code",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};

static struct resource bss_resource = {
	.name	= "Kernel bss",
	.start	= 0,
	.end	= 0,
	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};


#ifdef CONFIG_X86_32
/* CPU data as detected by the assembly code in head_32.S */
struct cpuinfo_x86 new_cpu_data;

/* Common CPU data for all CPUs */
struct cpuinfo_x86 boot_cpu_data __read_mostly;
EXPORT_SYMBOL(boot_cpu_data);

unsigned int def_to_bigsmp;

/* For MCA, but anyone else can use it if they want */
unsigned int machine_id;
unsigned int machine_submodel_id;
unsigned int BIOS_revision;

struct apm_info apm_info;
EXPORT_SYMBOL(apm_info);

#if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
struct ist_info ist_info;
EXPORT_SYMBOL(ist_info);
#else
struct ist_info ist_info;
#endif

#else
struct cpuinfo_x86 boot_cpu_data __read_mostly;
EXPORT_SYMBOL(boot_cpu_data);
#endif


#if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
__visible unsigned long mmu_cr4_features __ro_after_init;
#else
__visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
#endif

/* Boot loader ID and version as integers, for the benefit of proc_dointvec */
int bootloader_type, bootloader_version;

/*
 * Setup options
 */
struct<