Files
linux/arch/x86/include/asm/boot.h
Linus Torvalds d71ec0ed03 Merge tag 'x86-build-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build updates from Ingo Molnar:

 - Use -fpic to build the kexec 'purgatory' (the self-contained
   code that runs between two kernels)

 - Clean up vmlinux.lds.S generation

 - Simplify the X86_EXTENDED_PLATFORM section of the x86 Kconfig

 - Misc cleanups & fixes

* tag 'x86-build-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/Kconfig: Merge the two CONFIG_X86_EXTENDED_PLATFORM entries
  x86/purgatory: Switch to the position-independent small code model
  x86/boot: Replace __PHYSICAL_START with LOAD_PHYSICAL_ADDR
  x86/vmlinux.lds.S: Take __START_KERNEL out conditional definition
  x86/vmlinux.lds.S: Remove conditional definition of LOAD_OFFSET
  vmlinux.lds.h: Fix a typo in comment
2024-05-13 18:05:08 -07:00

89 lines
2.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_BOOT_H
#define _ASM_X86_BOOT_H
#include <asm/pgtable_types.h>
#include <uapi/asm/boot.h>
/* Minimum kernel alignment, as a power of two */
#ifdef CONFIG_X86_64
# define MIN_KERNEL_ALIGN_LG2 PMD_SHIFT
#else
# define MIN_KERNEL_ALIGN_LG2 (PAGE_SHIFT + THREAD_SIZE_ORDER)
#endif
#define MIN_KERNEL_ALIGN (_AC(1, UL) << MIN_KERNEL_ALIGN_LG2)
#if (CONFIG_PHYSICAL_ALIGN & (CONFIG_PHYSICAL_ALIGN-1)) || \
(CONFIG_PHYSICAL_ALIGN < MIN_KERNEL_ALIGN)
# error "Invalid value for CONFIG_PHYSICAL_ALIGN"
#endif
#if defined(CONFIG_KERNEL_BZIP2)
# define BOOT_HEAP_SIZE 0x400000
#elif defined(CONFIG_KERNEL_ZSTD)
/*
* Zstd needs to allocate the ZSTD_DCtx in order to decompress the kernel.
* The ZSTD_DCtx is ~160KB, so set the heap size to 192KB because it is a
* round number and to allow some slack.
*/
# define BOOT_HEAP_SIZE 0x30000
#else
# define BOOT_HEAP_SIZE 0x10000
#endif
#ifdef CONFIG_X86_64
# define BOOT_STACK_SIZE 0x4000
/*
* Used by decompressor's startup_32() to allocate page tables for identity
* mapping of the 4G of RAM in 4-level paging mode:
* - 1 level4 table;
* - 1 level3 table;
* - 4 level2 table that maps everything with 2M pages;
*
* The additional level5 table needed for 5-level paging is allocated from
* trampoline_32bit memory.
*/
# define BOOT_INIT_PGT_SIZE (6*4096)
/*
* Total number of page tables kernel_add_identity_map() can allocate,
* including page tables consumed by startup_32().
*
* Worst-case scenario:
* - 5-level paging needs 1 level5 table;
* - KASLR needs to map kernel, boot_params, cmdline and randomized kernel,
* assuming all of them cross 256T boundary:
* + 4*2 level4 table;
* + 4*2 level3 table;
* + 4*2 level2 table;
* - X86_VERBOSE_BOOTUP needs to map the first 2M (video RAM):
* + 1 level4 table;
* + 1 level3 table;
* + 1 level2 table;
* Total: 28 tables
*
* Add 4 spare table in case decompressor touches anything beyond what is
* accounted above. Warn if it happens.
*/
# define BOOT_PGT_SIZE_WARN (28*4096)
# define BOOT_PGT_SIZE (32*4096)
#else /* !CONFIG_X86_64 */
# define BOOT_STACK_SIZE 0x1000
#endif
#ifndef __ASSEMBLY__
extern unsigned int output_len;
extern const unsigned long kernel_text_size;
extern const unsigned long kernel_total_size;
unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,
void (*error)(char *x));
extern struct boot_params *boot_params_ptr;
#endif
#endif /* _ASM_X86_BOOT_H */