include/asm/boot.h

1 /* SPDX-License-Identifier: GPL-2.0 */
17 #if (CONFIG_PHYSICAL_ALIGN & (CONFIG_PHYSICAL_ALIGN-1)) || \
27  * The ZSTD_DCtx is ~160KB, so set the heap size to 192KB because it is a
39  * Used by decompressor's startup_32() to allocate page tables for identity
40  * mapping of the 4G of RAM in 4-level paging mode:
41  * - 1 level4 table;
42  * - 1 level3 table;
43  * - 4 level2 table that maps everything with 2M pages;
45  * The additional level5 table needed for 5-level paging is allocated from
51  * Total number of page tables kernel_add_identity_map() can allocate,
52  * including page tables consumed by startup_32().
54  * Worst-case scenario:
55  *  - 5-level paging needs 1 level5 table;
56  *  - KASLR needs to map kernel, boot_params, cmdline and randomized kernel,
58  *    + 4*2 level4 table;
59  *    + 4*2 level3 table;
60  *    + 4*2 level2 table;
61  *  - X86_VERBOSE_BOOTUP needs to map the first 2M (video RAM):
67  * Add 4 spare table in case decompressor touches anything beyond what is