1 // SPDX-License-Identifier: GPL-2.0
49 	 * Only look for values in the legacy ROM for non-EFI system.  in find_trampoline_placement()
51 	signature = (char *)&boot_params_ptr->efi_info.efi_loader_signature;  in find_trampoline_placement()
67 	for (i = boot_params_ptr->e820_entries - 1; i >= 0; i--) {  in find_trampoline_placement()
70 		entry = &boot_params_ptr->e820_table[i];  in find_trampoline_placement()
73 		if (bios_start <= entry->addr)  in find_trampoline_placement()
76 		/* Skip non-RAM entries. */  in find_trampoline_placement()
77 		if (entry->type != E820_TYPE_RAM)  in find_trampoline_placement()
81 		if (bios_start > entry->addr + entry->size)  in find_trampoline_placement()
82 			new = entry->addr + entry->size;  in find_trampoline_placement()
84 		/* Keep bios_start page-aligned. */  in find_trampoline_placement()
88 		if (new - TRAMPOLINE_32BIT_SIZE < entry->addr)  in find_trampoline_placement()
92 		if (new - TRAMPOLINE_32BIT_SIZE > bios_start)  in find_trampoline_placement()
100 	return bios_start - TRAMPOLINE_32BIT_SIZE;  in find_trampoline_placement()
115 	 *   - if the kernel supports 5-level paging: CONFIG_X86_5LEVEL=y  in configure_5level_paging()
116 	 *   - if user asked to disable 5-level paging: no5lvl in cmdline  in configure_5level_paging()
117 	 *   - if the machine supports 5-level paging:  in configure_5level_paging()
129 		/* Initialize variables for 5-level paging */  in configure_5level_paging()
156 	 * Avoid the need for a stack in the 32-bit trampoline code, by using  in configure_5level_paging()
168 	 * from 4- to 5-level paging or vice versa.  in configure_5level_paging()
173 		 * For 4- to 5-level paging transition, set up current CR3 as  in configure_5level_paging()
174 		 * the first and the only entry in a new top-level page table.  in configure_5level_paging()
181 		 * For 5- to 4-level paging transition, copy page table pointed  in configure_5level_paging()
182 		 * by first entry in the current top-level page table as our  in configure_5level_paging()
183 		 * new top-level page table.  in configure_5level_paging()
195 	 * Move the top level page table out of trampoline memory.  in configure_5level_paging()