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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * prepare to run common code
4 *
5 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
6 */
7
8#define DISABLE_BRANCH_PROFILING
9#include <linux/init.h>
10#include <linux/linkage.h>
11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/string.h>
14#include <linux/percpu.h>
15#include <linux/start_kernel.h>
16#include <linux/io.h>
17#include <linux/memblock.h>
18#include <linux/mem_encrypt.h>
19
20#include <asm/processor.h>
21#include <asm/proto.h>
22#include <asm/smp.h>
23#include <asm/setup.h>
24#include <asm/desc.h>
25#include <asm/pgtable.h>
26#include <asm/tlbflush.h>
27#include <asm/sections.h>
28#include <asm/kdebug.h>
29#include <asm/e820/api.h>
30#include <asm/bios_ebda.h>
31#include <asm/bootparam_utils.h>
32#include <asm/microcode.h>
33#include <asm/kasan.h>
34
35#ifdef CONFIG_X86_5LEVEL
36#undef pgtable_l5_enabled
37#define pgtable_l5_enabled __pgtable_l5_enabled
38#endif
39
40/*
41 * Manage page tables very early on.
42 */
43extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
44static unsigned int __initdata next_early_pgt;
45pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
46
47#ifdef CONFIG_X86_5LEVEL
48unsigned int __pgtable_l5_enabled __ro_after_init;
49EXPORT_SYMBOL(__pgtable_l5_enabled);
50unsigned int pgdir_shift __ro_after_init = 39;
51EXPORT_SYMBOL(pgdir_shift);
52unsigned int ptrs_per_p4d __ro_after_init = 1;
53EXPORT_SYMBOL(ptrs_per_p4d);
54#endif
55
56#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
57unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;
58EXPORT_SYMBOL(page_offset_base);
59unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4;
60EXPORT_SYMBOL(vmalloc_base);
61unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
62EXPORT_SYMBOL(vmemmap_base);
63#endif
64
65#define __head __section(.head.text)
66
67static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
68{
69 return ptr - (void *)_text + (void *)physaddr;
70}
71
72static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)
73{
74 return fixup_pointer(ptr, physaddr);
75}
76
77#ifdef CONFIG_X86_5LEVEL
78static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
79{
80 return fixup_pointer(ptr, physaddr);
81}
82
83static bool __head check_la57_support(unsigned long physaddr)
84{
85 if (native_cpuid_eax(0) < 7)
86 return false;
87
88 if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
89 return false;
90
91 *fixup_int(&pgtable_l5_enabled, physaddr) = 1;
92 *fixup_int(&pgdir_shift, physaddr) = 48;
93 *fixup_int(&ptrs_per_p4d, physaddr) = 512;
94 *fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
95 *fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
96 *fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
97
98 return true;
99}
100#else
101static bool __head check_la57_support(unsigned long physaddr)
102{
103 return false;
104}
105#endif
106
107/* Code in __startup_64() can be relocated during execution, but the compiler
108 * doesn't have to generate PC-relative relocations when accessing globals from
109 * that function. Clang actually does not generate them, which leads to
110 * boot-time crashes. To work around this problem, every global pointer must
111 * be adjusted using fixup_pointer().
112 */
113unsigned long __head __startup_64(unsigned long physaddr,
114 struct boot_params *bp)
115{
116 unsigned long load_delta, *p;
117 unsigned long pgtable_flags;
118 pgdval_t *pgd;
119 p4dval_t *p4d;
120 pudval_t *pud;
121 pmdval_t *pmd, pmd_entry;
122 pteval_t *mask_ptr;
123 bool la57;
124 int i;
125 unsigned int *next_pgt_ptr;
126
127 la57 = check_la57_support(physaddr);
128
129 /* Is the address too large? */
130 if (physaddr >> MAX_PHYSMEM_BITS)
131 for (;;);
132
133 /*
134 * Compute the delta between the address I am compiled to run at
135 * and the address I am actually running at.
136 */
137 load_delta = physaddr - (unsigned long)(_text - __START_KERNEL_map);
138
139 /* Is the address not 2M aligned? */
140 if (load_delta & ~PMD_PAGE_MASK)
141 for (;;);
142
143 /* Activate Secure Memory Encryption (SME) if supported and enabled */
144 sme_enable(bp);
145
146 /* Include the SME encryption mask in the fixup value */
147 load_delta += sme_get_me_mask();
148
149 /* Fixup the physical addresses in the page table */
150
151 pgd = fixup_pointer(&early_top_pgt, physaddr);
152 p = pgd + pgd_index(__START_KERNEL_map);
153 if (la57)
154 *p = (unsigned long)level4_kernel_pgt;
155 else
156 *p = (unsigned long)level3_kernel_pgt;
157 *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
158
159 if (la57) {
160 p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
161 p4d[511] += load_delta;
162 }
163
164 pud = fixup_pointer(&level3_kernel_pgt, physaddr);
165 pud[510] += load_delta;
166 pud[511] += load_delta;
167
168 pmd = fixup_pointer(level2_fixmap_pgt, physaddr);
169 pmd[506] += load_delta;
170
171 /*
172 * Set up the identity mapping for the switchover. These
173 * entries should *NOT* have the global bit set! This also
174 * creates a bunch of nonsense entries but that is fine --
175 * it avoids problems around wraparound.
176 */
177
178 next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr);
179 pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
180 pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
181
182 pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
183
184 if (la57) {
185 p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
186
187 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
188 pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
189 pgd[i + 1] = (pgdval_t)p4d + pgtable_flags;
190
191 i = (physaddr >> P4D_SHIFT) % PTRS_PER_P4D;
192 p4d[i + 0] = (pgdval_t)pud + pgtable_flags;
193 p4d[i + 1] = (pgdval_t)pud + pgtable_flags;
194 } else {
195 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
196 pgd[i + 0] = (pgdval_t)pud + pgtable_flags;
197 pgd[i + 1] = (pgdval_t)pud + pgtable_flags;
198 }
199
200 i = (physaddr >> PUD_SHIFT) % PTRS_PER_PUD;
201 pud[i + 0] = (pudval_t)pmd + pgtable_flags;
202 pud[i + 1] = (pudval_t)pmd + pgtable_flags;
203
204 pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
205 /* Filter out unsupported __PAGE_KERNEL_* bits: */
206 mask_ptr = fixup_pointer(&__supported_pte_mask, physaddr);
207 pmd_entry &= *mask_ptr;
208 pmd_entry += sme_get_me_mask();
209 pmd_entry += physaddr;
210
211 for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) {
212 int idx = i + (physaddr >> PMD_SHIFT) % PTRS_PER_PMD;
213 pmd[idx] = pmd_entry + i * PMD_SIZE;
214 }
215
216 /*
217 * Fixup the kernel text+data virtual addresses. Note that
218 * we might write invalid pmds, when the kernel is relocated
219 * cleanup_highmap() fixes this up along with the mappings
220 * beyond _end.
221 */
222
223 pmd = fixup_pointer(level2_kernel_pgt, physaddr);
224 for (i = 0; i < PTRS_PER_PMD; i++) {
225 if (pmd[i] & _PAGE_PRESENT)
226 pmd[i] += load_delta;
227 }
228
229 /*
230 * Fixup phys_base - remove the memory encryption mask to obtain
231 * the true physical address.
232 */
233 *fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();
234
235 /* Encrypt the kernel and related (if SME is active) */
236 sme_encrypt_kernel(bp);
237
238 /*
239 * Return the SME encryption mask (if SME is active) to be used as a
240 * modifier for the initial pgdir entry programmed into CR3.
241 */
242 return sme_get_me_mask();
243}
244
245unsigned long __startup_secondary_64(void)
246{
247 /*
248 * Return the SME encryption mask (if SME is active) to be used as a
249 * modifier for the initial pgdir entry programmed into CR3.
250 */
251 return sme_get_me_mask();
252}
253
254/* Wipe all early page tables except for the kernel symbol map */
255static void __init reset_early_page_tables(void)
256{
257 memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
258 next_early_pgt = 0;
259 write_cr3(__sme_pa_nodebug(early_top_pgt));
260}
261
262/* Create a new PMD entry */
263int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
264{
265 unsigned long physaddr = address - __PAGE_OFFSET;
266 pgdval_t pgd, *pgd_p;
267 p4dval_t p4d, *p4d_p;
268 pudval_t pud, *pud_p;
269 pmdval_t *pmd_p;
270
271 /* Invalid address or early pgt is done ? */
272 if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt))
273 return -1;
274
275again:
276 pgd_p = &early_top_pgt[pgd_index(address)].pgd;
277 pgd = *pgd_p;
278
279 /*
280 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
281 * critical -- __PAGE_OFFSET would point us back into the dynamic
282 * range and we might end up looping forever...
283 */
284 if (!pgtable_l5_enabled)
285 p4d_p = pgd_p;
286 else if (pgd)
287 p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
288 else {
289 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
290 reset_early_page_tables();
291 goto again;
292 }
293
294 p4d_p = (p4dval_t *)early_dynamic_pgts[next_early_pgt++];
295 memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
296 *pgd_p = (pgdval_t)p4d_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
297 }
298 p4d_p += p4d_index(address);
299 p4d = *p4d_p;
300
301 if (p4d)
302 pud_p = (pudval_t *)((p4d & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
303 else {
304 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
305 reset_early_page_tables();
306 goto again;
307 }
308
309 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
310 memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
311 *p4d_p = (p4dval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
312 }
313 pud_p += pud_index(address);
314 pud = *pud_p;
315
316 if (pud)
317 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
318 else {
319 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
320 reset_early_page_tables();
321 goto again;
322 }
323
324 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
325 memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
326 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
327 }
328 pmd_p[pmd_index(address)] = pmd;
329
330 return 0;
331}
332
333int __init early_make_pgtable(unsigned long address)
334{
335 unsigned long physaddr = address - __PAGE_OFFSET;
336 pmdval_t pmd;
337
338 pmd = (physaddr & PMD_MASK) + early_pmd_flags;
339
340 return __early_make_pgtable(address, pmd);
341}
342
343/* Don't add a printk in there. printk relies on the PDA which is not initialized
344 yet. */
345static void __init clear_bss(void)
346{
347 memset(__bss_start, 0,
348 (unsigned long) __bss_stop - (unsigned long) __bss_start);
349}
350
351static unsigned long get_cmd_line_ptr(void)
352{
353 unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
354
355 cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32;
356
357 return cmd_line_ptr;
358}
359
360static void __init copy_bootdata(char *real_mode_data)
361{
362 char * command_line;
363 unsigned long cmd_line_ptr;
364
365 /*
366 * If SME is active, this will create decrypted mappings of the
367 * boot data in advance of the copy operations.
368 */
369 sme_map_bootdata(real_mode_data);
370
371 memcpy(&boot_params, real_mode_data, sizeof boot_params);
372 sanitize_boot_params(&boot_params);
373 cmd_line_ptr = get_cmd_line_ptr();
374 if (cmd_line_ptr) {
375 command_line = __va(cmd_line_ptr);
376 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
377 }
378
379 /*
380 * The old boot data is no longer needed and won't be reserved,
381 * freeing up that memory for use by the system. If SME is active,
382 * we need to remove the mappings that were created so that the
383 * memory doesn't remain mapped as decrypted.
384 */
385 sme_unmap_bootdata(real_mode_data);
386}
387
388asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
389{
390 /*
391 * Build-time sanity checks on the kernel image and module
392 * area mappings. (these are purely build-time and produce no code)
393 */
394 BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map);
395 BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE);
396 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
397 BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0);
398 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
399 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
400 MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
401 (__START_KERNEL & PGDIR_MASK)));
402 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
403
404 cr4_init_shadow();
405
406 /* Kill off the identity-map trampoline */
407 reset_early_page_tables();
408
409 clear_bss();
410
411 clear_page(init_top_pgt);
412
413 /*
414 * SME support may update early_pmd_flags to include the memory
415 * encryption mask, so it needs to be called before anything
416 * that may generate a page fault.
417 */
418 sme_early_init();
419
420 kasan_early_init();
421
422 idt_setup_early_handler();
423
424 copy_bootdata(__va(real_mode_data));
425
426 /*
427 * Load microcode early on BSP.
428 */
429 load_ucode_bsp();
430
431 /* set init_top_pgt kernel high mapping*/
432 init_top_pgt[511] = early_top_pgt[511];
433
434 x86_64_start_reservations(real_mode_data);
435}
436
437void __init x86_64_start_reservations(char *real_mode_data)
438{
439 /* version is always not zero if it is copied */
440 if (!boot_params.hdr.version)
441 copy_bootdata(__va(real_mode_data));
442
443 x86_early_init_platform_quirks();
444
445 switch (boot_params.hdr.hardware_subarch) {
446 case X86_SUBARCH_INTEL_MID:
447 x86_intel_mid_early_setup();
448 break;
449 default:
450 break;
451 }
452
453 start_kernel();
454}
1/*
2 * prepare to run common code
3 *
4 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
5 */
6
7#include <linux/init.h>
8#include <linux/linkage.h>
9#include <linux/types.h>
10#include <linux/kernel.h>
11#include <linux/string.h>
12#include <linux/percpu.h>
13#include <linux/start_kernel.h>
14#include <linux/io.h>
15#include <linux/memblock.h>
16
17#include <asm/processor.h>
18#include <asm/proto.h>
19#include <asm/smp.h>
20#include <asm/setup.h>
21#include <asm/desc.h>
22#include <asm/pgtable.h>
23#include <asm/tlbflush.h>
24#include <asm/sections.h>
25#include <asm/kdebug.h>
26#include <asm/e820.h>
27#include <asm/bios_ebda.h>
28#include <asm/bootparam_utils.h>
29#include <asm/microcode.h>
30#include <asm/kasan.h>
31
32/*
33 * Manage page tables very early on.
34 */
35extern pgd_t early_level4_pgt[PTRS_PER_PGD];
36extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
37static unsigned int __initdata next_early_pgt = 2;
38pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
39
40/* Wipe all early page tables except for the kernel symbol map */
41static void __init reset_early_page_tables(void)
42{
43 memset(early_level4_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
44 next_early_pgt = 0;
45 write_cr3(__pa_nodebug(early_level4_pgt));
46}
47
48/* Create a new PMD entry */
49int __init early_make_pgtable(unsigned long address)
50{
51 unsigned long physaddr = address - __PAGE_OFFSET;
52 pgdval_t pgd, *pgd_p;
53 pudval_t pud, *pud_p;
54 pmdval_t pmd, *pmd_p;
55
56 /* Invalid address or early pgt is done ? */
57 if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt))
58 return -1;
59
60again:
61 pgd_p = &early_level4_pgt[pgd_index(address)].pgd;
62 pgd = *pgd_p;
63
64 /*
65 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
66 * critical -- __PAGE_OFFSET would point us back into the dynamic
67 * range and we might end up looping forever...
68 */
69 if (pgd)
70 pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
71 else {
72 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
73 reset_early_page_tables();
74 goto again;
75 }
76
77 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
78 memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
79 *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
80 }
81 pud_p += pud_index(address);
82 pud = *pud_p;
83
84 if (pud)
85 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
86 else {
87 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
88 reset_early_page_tables();
89 goto again;
90 }
91
92 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
93 memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
94 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
95 }
96 pmd = (physaddr & PMD_MASK) + early_pmd_flags;
97 pmd_p[pmd_index(address)] = pmd;
98
99 return 0;
100}
101
102/* Don't add a printk in there. printk relies on the PDA which is not initialized
103 yet. */
104static void __init clear_bss(void)
105{
106 memset(__bss_start, 0,
107 (unsigned long) __bss_stop - (unsigned long) __bss_start);
108}
109
110static unsigned long get_cmd_line_ptr(void)
111{
112 unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
113
114 cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32;
115
116 return cmd_line_ptr;
117}
118
119static void __init copy_bootdata(char *real_mode_data)
120{
121 char * command_line;
122 unsigned long cmd_line_ptr;
123
124 memcpy(&boot_params, real_mode_data, sizeof boot_params);
125 sanitize_boot_params(&boot_params);
126 cmd_line_ptr = get_cmd_line_ptr();
127 if (cmd_line_ptr) {
128 command_line = __va(cmd_line_ptr);
129 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
130 }
131}
132
133asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
134{
135 int i;
136
137 /*
138 * Build-time sanity checks on the kernel image and module
139 * area mappings. (these are purely build-time and produce no code)
140 */
141 BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map);
142 BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE);
143 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
144 BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0);
145 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
146 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
147 BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
148 (__START_KERNEL & PGDIR_MASK)));
149 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
150
151 cr4_init_shadow();
152
153 /* Kill off the identity-map trampoline */
154 reset_early_page_tables();
155
156 clear_bss();
157
158 clear_page(init_level4_pgt);
159
160 kasan_early_init();
161
162 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
163 set_intr_gate(i, early_idt_handler_array[i]);
164 load_idt((const struct desc_ptr *)&idt_descr);
165
166 copy_bootdata(__va(real_mode_data));
167
168 /*
169 * Load microcode early on BSP.
170 */
171 load_ucode_bsp();
172
173 /* set init_level4_pgt kernel high mapping*/
174 init_level4_pgt[511] = early_level4_pgt[511];
175
176 x86_64_start_reservations(real_mode_data);
177}
178
179void __init x86_64_start_reservations(char *real_mode_data)
180{
181 /* version is always not zero if it is copied */
182 if (!boot_params.hdr.version)
183 copy_bootdata(__va(real_mode_data));
184
185 reserve_ebda_region();
186
187 switch (boot_params.hdr.hardware_subarch) {
188 case X86_SUBARCH_INTEL_MID:
189 x86_intel_mid_early_setup();
190 break;
191 default:
192 break;
193 }
194
195 start_kernel();
196}