1 files changed, 82 insertions, 0 deletions
diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
new file mode 100644
index 000000000..215d37f7d
--- /dev/null
+++ b/arch/x86/include/asm/boot.h
@@ -0,0 +1,82 @@
+/* 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>
+
+/* Physical address where kernel should be loaded. */
+#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
+				+ (CONFIG_PHYSICAL_ALIGN - 1)) \
+				& ~(CONFIG_PHYSICAL_ALIGN - 1))
+
+/* 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
+
+#endif /* _ASM_X86_BOOT_H */