xref: /freebsd/sys/arm64/arm64/locore.S (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1/*-
2 * Copyright (c) 2012-2014 Andrew Turner
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#include "assym.inc"
30#include "opt_kstack_pages.h"
31#include <sys/syscall.h>
32#include <machine/asm.h>
33#include <machine/armreg.h>
34#include <machine/hypervisor.h>
35#include <machine/param.h>
36#include <machine/pte.h>
37#include <machine/vm.h>
38#include <machine/vmparam.h>
39
40#define	VIRT_BITS	48
41
42#if PAGE_SIZE == PAGE_SIZE_16K
43/*
44 * The number of level 3 tables to create. 32 will allow for 1G of address
45 * space, the same as a single level 2 page with 4k pages.
46 */
47#define	L3_PAGE_COUNT	32
48#endif
49
50	.globl	kernbase
51	.set	kernbase, KERNBASE
52
53/*
54 * We assume:
55 *  MMU      on with an identity map, or off
56 *  D-Cache: off
57 *  I-Cache: on or off
58 *  We are loaded at a 2MiB aligned address
59 */
60
61ENTRY(_start)
62	/* Drop to EL1 */
63	bl	drop_to_el1
64
65	/*
66	 * Disable the MMU. We may have entered the kernel with it on and
67	 * will need to update the tables later. If this has been set up
68	 * with anything other than a VA == PA map then this will fail,
69	 * but in this case the code to find where we are running from
70	 * would have also failed.
71	 */
72	dsb	sy
73	mrs	x2, sctlr_el1
74	bic	x2, x2, SCTLR_M
75	msr	sctlr_el1, x2
76	isb
77
78	/* Set the context id */
79	msr	contextidr_el1, xzr
80
81	/* Get the virt -> phys offset */
82	bl	get_virt_delta
83
84	/*
85	 * At this point:
86	 * x29 = PA - VA
87	 * x28 = Our physical load address
88	 */
89
90	/* Create the page tables */
91	bl	create_pagetables
92
93	/*
94	 * At this point:
95	 * x27 = TTBR0 table
96	 * x26 = Kernel L1 table
97	 * x24 = TTBR1 table
98	 */
99
100	/* Enable the mmu */
101	bl	start_mmu
102
103	/* Load the new ttbr0 pagetable */
104	adrp	x27, pagetable_l0_ttbr0
105	add	x27, x27, :lo12:pagetable_l0_ttbr0
106
107	/* Jump to the virtual address space */
108	ldr	x15, .Lvirtdone
109	br	x15
110
111virtdone:
112	/* Set up the stack */
113	adrp	x25, initstack_end
114	add	x25, x25, :lo12:initstack_end
115	mov	sp, x25
116	sub	sp, sp, #PCB_SIZE
117
118	/* Zero the BSS */
119	ldr	x15, .Lbss
120	ldr	x14, .Lend
1211:
122	str	xzr, [x15], #8
123	cmp	x15, x14
124	b.lo	1b
125
126#if defined(PERTHREAD_SSP)
127	/* Set sp_el0 to the boot canary for early per-thread SSP to work */
128	adrp	x15, boot_canary
129	add	x15, x15, :lo12:boot_canary
130	msr	sp_el0, x15
131#endif
132
133	/* Backup the module pointer */
134	mov	x1, x0
135
136	sub	sp, sp, #BOOTPARAMS_SIZE
137	mov	x0, sp
138
139	/* Degate the delda so it is VA -> PA */
140	neg	x29, x29
141
142	str	x1,  [x0, #BP_MODULEP]
143	str	x29, [x0, #BP_KERN_DELTA]
144	adrp	x25, initstack
145	add	x25, x25, :lo12:initstack
146	str	x25, [x0, #BP_KERN_STACK]
147	str	x27, [x0, #BP_KERN_TTBR0]
148	str	x23, [x0, #BP_BOOT_EL]
149	str	x4,  [x0, #BP_HCR_EL2]
150
151#ifdef KASAN
152	/* Save bootparams */
153	mov	x19, x0
154
155	/* Bootstrap an early shadow map for the boot stack. */
156	bl	pmap_san_bootstrap
157
158	/* Restore bootparams */
159	mov	x0, x19
160#endif
161
162	/* trace back starts here */
163	mov	fp, #0
164	/* Branch to C code */
165	bl	initarm
166	/* We are done with the boot params */
167	add	sp, sp, #BOOTPARAMS_SIZE
168
169	/*
170	 * Enable pointer authentication in the kernel. We set the keys for
171	 * thread0 in initarm so have to wait until it returns to enable it.
172	 * If we were to enable it in initarm then any authentication when
173	 * returning would fail as it was called with pointer authentication
174	 * disabled.
175	 */
176	bl	ptrauth_start
177
178	bl	mi_startup
179
180	/* We should not get here */
181	brk	0
182
183	.align 3
184.Lvirtdone:
185	.quad	virtdone
186.Lbss:
187	.quad	__bss_start
188.Lend:
189	.quad	__bss_end
190END(_start)
191
192#ifdef SMP
193/*
194 * mpentry(unsigned long)
195 *
196 * Called by a core when it is being brought online.
197 * The data in x0 is passed straight to init_secondary.
198 */
199ENTRY(mpentry)
200	/* Disable interrupts */
201	msr	daifset, #DAIF_INTR
202
203	/* Drop to EL1 */
204	bl	drop_to_el1
205
206	/* Set the context id */
207	msr	contextidr_el1, xzr
208
209	/* Load the kernel page table */
210	adrp	x24, pagetable_l0_ttbr1
211	add	x24, x24, :lo12:pagetable_l0_ttbr1
212	/* Load the identity page table */
213	adrp	x27, pagetable_l0_ttbr0_boostrap
214	add	x27, x27, :lo12:pagetable_l0_ttbr0_boostrap
215
216	/* Enable the mmu */
217	bl	start_mmu
218
219	/* Load the new ttbr0 pagetable */
220	adrp	x27, pagetable_l0_ttbr0
221	add	x27, x27, :lo12:pagetable_l0_ttbr0
222
223	/* Jump to the virtual address space */
224	ldr	x15, =mp_virtdone
225	br	x15
226
227mp_virtdone:
228	/* Start using the AP boot stack */
229	ldr	x4, =bootstack
230	ldr	x4, [x4]
231	mov	sp, x4
232
233#if defined(PERTHREAD_SSP)
234	/* Set sp_el0 to the boot canary for early per-thread SSP to work */
235	adrp	x15, boot_canary
236	add	x15, x15, :lo12:boot_canary
237	msr	sp_el0, x15
238#endif
239
240	/* Load the kernel ttbr0 pagetable */
241	msr	ttbr0_el1, x27
242	isb
243
244	/* Invalidate the TLB */
245	tlbi	vmalle1
246	dsb	sy
247	isb
248
249	b	init_secondary
250END(mpentry)
251#endif
252
253/*
254 * If we are started in EL2, configure the required hypervisor
255 * registers and drop to EL1.
256 */
257LENTRY(drop_to_el1)
258	mrs	x23, CurrentEL
259	lsr	x23, x23, #2
260	cmp	x23, #0x2
261	b.eq	1f
262	ret
2631:
264	/*
265	 * Disable the MMU. If the HCR_EL2.E2H field is set we will clear it
266	 * which may break address translation.
267	 */
268	dsb	sy
269	mrs	x2, sctlr_el2
270	bic	x2, x2, SCTLR_M
271	msr	sctlr_el2, x2
272	isb
273
274	/* Configure the Hypervisor */
275	ldr	x2, =(HCR_RW | HCR_APK | HCR_API)
276	msr	hcr_el2, x2
277
278	/* Stash value of HCR_EL2 for later */
279	isb
280	mrs	x4, hcr_el2
281
282	/* Load the Virtualization Process ID Register */
283	mrs	x2, midr_el1
284	msr	vpidr_el2, x2
285
286	/* Load the Virtualization Multiprocess ID Register */
287	mrs	x2, mpidr_el1
288	msr	vmpidr_el2, x2
289
290	/* Set the bits that need to be 1 in sctlr_el1 */
291	ldr	x2, .Lsctlr_res1
292	msr	sctlr_el1, x2
293
294	/*
295	 * On some hardware, e.g., Apple M1, we can't clear E2H, so make sure we
296	 * don't trap to EL2 for SIMD register usage to have at least a
297	 * minimally usable system.
298	 */
299	tst	x4, #HCR_E2H
300	mov	x3, #CPTR_RES1	/* HCR_E2H == 0 */
301	mov	x5, #CPTR_FPEN	/* HCR_E2H == 1 */
302	csel	x2, x3, x5, eq
303	msr	cptr_el2, x2
304
305	/* Don't trap to EL2 for CP15 traps */
306	msr	hstr_el2, xzr
307
308	/* Enable access to the physical timers at EL1 */
309	mrs	x2, cnthctl_el2
310	orr	x2, x2, #(CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN)
311	msr	cnthctl_el2, x2
312
313	/* Set the counter offset to a known value */
314	msr	cntvoff_el2, xzr
315
316	/* Hypervisor trap functions */
317	adrp	x2, hyp_stub_vectors
318	add	x2, x2, :lo12:hyp_stub_vectors
319	msr	vbar_el2, x2
320
321	/* Zero vttbr_el2 so a hypervisor can tell the host and guest apart */
322	msr	vttbr_el2, xzr
323
324	mov	x2, #(PSR_DAIF | PSR_M_EL1h)
325	msr	spsr_el2, x2
326
327	/* Configure GICv3 CPU interface */
328	mrs	x2, id_aa64pfr0_el1
329	/* Extract GIC bits from the register */
330	ubfx	x2, x2, #ID_AA64PFR0_GIC_SHIFT, #ID_AA64PFR0_GIC_BITS
331	/* GIC[3:0] == 0001 - GIC CPU interface via special regs. supported */
332	cmp	x2, #(ID_AA64PFR0_GIC_CPUIF_EN >> ID_AA64PFR0_GIC_SHIFT)
333	b.ne	2f
334
335	mrs	x2, icc_sre_el2
336	orr	x2, x2, #ICC_SRE_EL2_EN	/* Enable access from insecure EL1 */
337	orr	x2, x2, #ICC_SRE_EL2_SRE	/* Enable system registers */
338	msr	icc_sre_el2, x2
3392:
340
341	/* Set the address to return to our return address */
342	msr	elr_el2, x30
343	isb
344
345	eret
346
347	.align 3
348.Lsctlr_res1:
349	.quad SCTLR_RES1
350LEND(drop_to_el1)
351
352/*
353 * Get the delta between the physical address we were loaded to and the
354 * virtual address we expect to run from. This is used when building the
355 * initial page table.
356 */
357LENTRY(get_virt_delta)
358	/* Load the physical address of virt_map */
359	adrp	x29, virt_map
360	add	x29, x29, :lo12:virt_map
361	/* Load the virtual address of virt_map stored in virt_map */
362	ldr	x28, [x29]
363	/* Find PA - VA as PA' = VA' - VA + PA = VA' + (PA - VA) = VA' + x29 */
364	sub	x29, x29, x28
365	/* Find the load address for the kernel */
366	mov	x28, #(KERNBASE)
367	add	x28, x28, x29
368	ret
369
370	.align 3
371virt_map:
372	.quad	virt_map
373LEND(get_virt_delta)
374
375/*
376 * This builds the page tables containing the identity map, and the kernel
377 * virtual map.
378 *
379 * It relys on:
380 *  We were loaded to an address that is on a 2MiB boundary
381 *  All the memory must not cross a 1GiB boundaty
382 *  x28 contains the physical address we were loaded from
383 *
384 * TODO: This is out of date.
385 *  There are at least 5 pages before that address for the page tables
386 *   The pages used are:
387 *    - The Kernel L2 table
388 *    - The Kernel L1 table
389 *    - The Kernel L0 table             (TTBR1)
390 *    - The identity (PA = VA) L1 table
391 *    - The identity (PA = VA) L0 table (TTBR0)
392 */
393LENTRY(create_pagetables)
394	/* Save the Link register */
395	mov	x5, x30
396
397	/* Clean the page table */
398	adrp	x6, pagetable
399	add	x6, x6, :lo12:pagetable
400	mov	x26, x6
401	adrp	x27, pagetable_end
402	add	x27, x27, :lo12:pagetable_end
4031:
404	stp	xzr, xzr, [x6], #16
405	stp	xzr, xzr, [x6], #16
406	stp	xzr, xzr, [x6], #16
407	stp	xzr, xzr, [x6], #16
408	cmp	x6, x27
409	b.lo	1b
410
411	/*
412	 * Build the TTBR1 maps.
413	 */
414
415	/* Find the size of the kernel */
416	mov	x6, #(KERNBASE)
417
418#if defined(LINUX_BOOT_ABI)
419	/* X19 is used as 'map FDT data' flag */
420	mov	x19, xzr
421
422	/* No modules or FDT pointer ? */
423	cbz	x0, booti_no_fdt
424
425	/*
426	 * Test if x0 points to modules descriptor(virtual address) or
427	 * to FDT (physical address)
428	 */
429	cmp	x0, x6		/* x6 is #(KERNBASE) */
430	b.lo	booti_fdt
431#endif
432
433	/* Booted with modules pointer */
434	/* Find modulep - begin */
435	sub	x8, x0, x6
436	/*
437	 * Add space for the module data. When PAGE_SIZE is 4k this will
438	 * add at least 2 level 2 blocks (2 * 2MiB). When PAGE_SIZE is
439	 * larger it will be at least as large as we use smaller level 3
440	 * pages.
441	 */
442	ldr	x7, =((6 * 1024 * 1024) - 1)
443	add	x8, x8, x7
444	b	common
445
446#if defined(LINUX_BOOT_ABI)
447booti_fdt:
448	/* Booted by U-Boot booti with FDT data */
449	/* Set 'map FDT data' flag */
450	mov	x19, #1
451
452booti_no_fdt:
453	/* Booted by U-Boot booti without FTD data */
454	/* Find the end - begin */
455	ldr     x7, .Lend
456	sub     x8, x7, x6
457
458	/*
459	 * Add one 2MiB page for copy of FDT data (maximum FDT size),
460	 * one for metadata and round up
461	 */
462	ldr	x7, =(3 * L2_SIZE - 1)
463	add	x8, x8, x7
464#endif
465
466common:
467#if PAGE_SIZE != PAGE_SIZE_4K
468	/*
469	 * Create L3 pages. The kernel will be loaded at a 2M aligned
470	 * address, however L2 blocks are too large when the page size is
471	 * not 4k to map the kernel with such an aligned address. However,
472	 * when the page size is larger than 4k, L2 blocks are too large to
473	 * map the kernel with such an alignment.
474	 */
475
476	/* Get the number of l3 pages to allocate, rounded down */
477	lsr	x10, x8, #(L3_SHIFT)
478
479	/* Create the kernel space L2 table */
480	mov	x6, x26
481	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
482	mov	x8, #(KERNBASE)
483	mov	x9, x28
484	bl	build_l3_page_pagetable
485
486	/* Move to the l2 table */
487	ldr	x9, =(PAGE_SIZE * L3_PAGE_COUNT)
488	add	x26, x26, x9
489
490	/* Link the l2 -> l3 table */
491	mov	x9, x6
492	mov	x6, x26
493	bl	link_l2_pagetable
494#else
495	/* Get the number of l2 pages to allocate, rounded down */
496	lsr	x10, x8, #(L2_SHIFT)
497
498	/* Create the kernel space L2 table */
499	mov	x6, x26
500	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
501	mov	x8, #(KERNBASE)
502	mov	x9, x28
503	bl	build_l2_block_pagetable
504#endif
505
506	/* Move to the l1 table */
507	add	x26, x26, #PAGE_SIZE
508
509	/* Link the l1 -> l2 table */
510	mov	x9, x6
511	mov	x6, x26
512	bl	link_l1_pagetable
513
514	/* Move to the l0 table */
515	add	x24, x26, #PAGE_SIZE
516
517	/* Link the l0 -> l1 table */
518	mov	x9, x6
519	mov	x6, x24
520	mov	x10, #1
521	bl	link_l0_pagetable
522
523	/*
524	 * Build the TTBR0 maps.  As TTBR0 maps, they must specify ATTR_S1_nG.
525	 * They are only needed early on, so the VA = PA map is uncached.
526	 */
527	add	x27, x24, #PAGE_SIZE
528
529	mov	x6, x27		/* The initial page table */
530
531	/* Create the VA = PA map */
532	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
533	adrp	x16, _start
534	and	x16, x16, #(~L2_OFFSET)
535	mov	x9, x16		/* PA start */
536	mov	x8, x16		/* VA start (== PA start) */
537	mov	x10, #1
538	bl	build_l2_block_pagetable
539
540#if defined(SOCDEV_PA)
541	/* Create a table for the UART */
542	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_DEVICE))
543	ldr	x9, =(L2_SIZE)
544	add	x16, x16, x9	/* VA start */
545	mov	x8, x16
546
547	/* Store the socdev virtual address */
548	add	x17, x8, #(SOCDEV_PA & L2_OFFSET)
549	adrp	x9, socdev_va
550	str	x17, [x9, :lo12:socdev_va]
551
552	mov	x9, #(SOCDEV_PA & ~L2_OFFSET)	/* PA start */
553	mov	x10, #1
554	bl	build_l2_block_pagetable
555#endif
556
557#if defined(LINUX_BOOT_ABI)
558	/* Map FDT data ? */
559	cbz	x19, 1f
560
561	/* Create the mapping for FDT data (2 MiB max) */
562	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
563	ldr	x9, =(L2_SIZE)
564	add	x16, x16, x9	/* VA start */
565	mov	x8, x16
566	mov	x9, x0			/* PA start */
567	/* Update the module pointer to point at the allocated memory */
568	and	x0, x0, #(L2_OFFSET)	/* Keep the lower bits */
569	add	x0, x0, x8		/* Add the aligned virtual address */
570
571	mov	x10, #1
572	bl	build_l2_block_pagetable
573
5741:
575#endif
576
577	/* Move to the l1 table */
578	add	x27, x27, #PAGE_SIZE
579
580	/* Link the l1 -> l2 table */
581	mov	x9, x6
582	mov	x6, x27
583	bl	link_l1_pagetable
584
585	/* Move to the l0 table */
586	add	x27, x27, #PAGE_SIZE
587
588	/* Link the l0 -> l1 table */
589	mov	x9, x6
590	mov	x6, x27
591	mov	x10, #1
592	bl	link_l0_pagetable
593
594	/* Restore the Link register */
595	mov	x30, x5
596	ret
597LEND(create_pagetables)
598
599/*
600 * Builds an L0 -> L1 table descriptor
601 *
602 *  x6  = L0 table
603 *  x8  = Virtual Address
604 *  x9  = L1 PA (trashed)
605 *  x10 = Entry count (trashed)
606 *  x11, x12 and x13 are trashed
607 */
608LENTRY(link_l0_pagetable)
609	/*
610	 * Link an L0 -> L1 table entry.
611	 */
612	/* Find the table index */
613	lsr	x11, x8, #L0_SHIFT
614	and	x11, x11, #L0_ADDR_MASK
615
616	/* Build the L0 block entry */
617	mov	x12, #L0_TABLE
618	orr	x12, x12, #(TATTR_UXN_TABLE | TATTR_AP_TABLE_NO_EL0)
619
620	/* Only use the output address bits */
621	lsr	x9, x9, #PAGE_SHIFT
6221:	orr	x13, x12, x9, lsl #PAGE_SHIFT
623
624	/* Store the entry */
625	str	x13, [x6, x11, lsl #3]
626
627	sub	x10, x10, #1
628	add	x11, x11, #1
629	add	x9, x9, #1
630	cbnz	x10, 1b
631
632	ret
633LEND(link_l0_pagetable)
634
635/*
636 * Builds an L1 -> L2 table descriptor
637 *
638 *  x6  = L1 table
639 *  x8  = Virtual Address
640 *  x9  = L2 PA (trashed)
641 *  x11, x12 and x13 are trashed
642 */
643LENTRY(link_l1_pagetable)
644	/*
645	 * Link an L1 -> L2 table entry.
646	 */
647	/* Find the table index */
648	lsr	x11, x8, #L1_SHIFT
649	and	x11, x11, #Ln_ADDR_MASK
650
651	/* Build the L1 block entry */
652	mov	x12, #L1_TABLE
653
654	/* Only use the output address bits */
655	lsr	x9, x9, #PAGE_SHIFT
656	orr	x13, x12, x9, lsl #PAGE_SHIFT
657
658	/* Store the entry */
659	str	x13, [x6, x11, lsl #3]
660
661	ret
662LEND(link_l1_pagetable)
663
664/*
665 * Builds count 2 MiB page table entry
666 *  x6  = L2 table
667 *  x7  = Block attributes
668 *  x8  = VA start
669 *  x9  = PA start (trashed)
670 *  x10 = Entry count (trashed)
671 *  x11, x12 and x13 are trashed
672 */
673LENTRY(build_l2_block_pagetable)
674	/*
675	 * Build the L2 table entry.
676	 */
677	/* Find the table index */
678	lsr	x11, x8, #L2_SHIFT
679	and	x11, x11, #Ln_ADDR_MASK
680
681	/* Build the L2 block entry */
682	orr	x12, x7, #L2_BLOCK
683	orr	x12, x12, #(ATTR_DEFAULT)
684	orr	x12, x12, #(ATTR_S1_UXN)
685
686	/* Only use the output address bits */
687	lsr	x9, x9, #L2_SHIFT
688
689	/* Set the physical address for this virtual address */
6901:	orr	x13, x12, x9, lsl #L2_SHIFT
691
692	/* Store the entry */
693	str	x13, [x6, x11, lsl #3]
694
695	sub	x10, x10, #1
696	add	x11, x11, #1
697	add	x9, x9, #1
698	cbnz	x10, 1b
699
700	ret
701LEND(build_l2_block_pagetable)
702
703#if PAGE_SIZE != PAGE_SIZE_4K
704/*
705 * Builds an L2 -> L3 table descriptor
706 *
707 *  x6  = L2 table
708 *  x8  = Virtual Address
709 *  x9  = L3 PA (trashed)
710 *  x11, x12 and x13 are trashed
711 */
712LENTRY(link_l2_pagetable)
713	/*
714	 * Link an L2 -> L3 table entry.
715	 */
716	/* Find the table index */
717	lsr	x11, x8, #L2_SHIFT
718	and	x11, x11, #Ln_ADDR_MASK
719
720	/* Build the L1 block entry */
721	mov	x12, #L2_TABLE
722
723	/* Only use the output address bits */
724	lsr	x9, x9, #PAGE_SHIFT
725	orr	x13, x12, x9, lsl #PAGE_SHIFT
726
727	/* Store the entry */
728	str	x13, [x6, x11, lsl #3]
729
730	ret
731LEND(link_l2_pagetable)
732
733/*
734 * Builds count level 3 page table entries
735 *  x6  = L3 table
736 *  x7  = Block attributes
737 *  x8  = VA start
738 *  x9  = PA start (trashed)
739 *  x10 = Entry count (trashed)
740 *  x11, x12 and x13 are trashed
741 */
742LENTRY(build_l3_page_pagetable)
743	/*
744	 * Build the L3 table entry.
745	 */
746	/* Find the table index */
747	lsr	x11, x8, #L3_SHIFT
748	and	x11, x11, #Ln_ADDR_MASK
749
750	/* Build the L3 page entry */
751	orr	x12, x7, #L3_PAGE
752	orr	x12, x12, #(ATTR_DEFAULT)
753	orr	x12, x12, #(ATTR_S1_UXN)
754
755	/* Only use the output address bits */
756	lsr	x9, x9, #L3_SHIFT
757
758	/* Set the physical address for this virtual address */
7591:	orr	x13, x12, x9, lsl #L3_SHIFT
760
761	/* Store the entry */
762	str	x13, [x6, x11, lsl #3]
763
764	sub	x10, x10, #1
765	add	x11, x11, #1
766	add	x9, x9, #1
767	cbnz	x10, 1b
768
769	ret
770LEND(build_l3_page_pagetable)
771#endif
772
773LENTRY(start_mmu)
774	dsb	sy
775
776	/* Load the exception vectors */
777	ldr	x2, =exception_vectors
778	msr	vbar_el1, x2
779
780	/* Load ttbr0 and ttbr1 */
781	msr	ttbr0_el1, x27
782	msr	ttbr1_el1, x24
783	isb
784
785	/* Clear the Monitor Debug System control register */
786	msr	mdscr_el1, xzr
787
788	/* Invalidate the TLB */
789	tlbi	vmalle1is
790	dsb	ish
791	isb
792
793	ldr	x2, mair
794	msr	mair_el1, x2
795
796	/*
797	 * Setup TCR according to the PARange and ASIDBits fields
798	 * from ID_AA64MMFR0_EL1 and the HAFDBS field from the
799	 * ID_AA64MMFR1_EL1.  More precisely, set TCR_EL1.AS
800	 * to 1 only if the ASIDBits field equals 0b0010.
801	 */
802	ldr	x2, tcr
803	mrs	x3, id_aa64mmfr0_el1
804
805	/* Copy the bottom 3 bits from id_aa64mmfr0_el1 into TCR.IPS */
806	bfi	x2, x3, #(TCR_IPS_SHIFT), #(TCR_IPS_WIDTH)
807	and	x3, x3, #(ID_AA64MMFR0_ASIDBits_MASK)
808
809	/* Check if the HW supports 16 bit ASIDS */
810	cmp	x3, #(ID_AA64MMFR0_ASIDBits_16)
811	/* If so x3 == 1, else x3 == 0 */
812	cset	x3, eq
813	/* Set TCR.AS with x3 */
814	bfi	x2, x3, #(TCR_ASID_SHIFT), #(TCR_ASID_WIDTH)
815
816	/*
817	 * Check if the HW supports access flag and dirty state updates,
818	 * and set TCR_EL1.HA and TCR_EL1.HD accordingly.
819	 */
820	mrs	x3, id_aa64mmfr1_el1
821	and	x3, x3, #(ID_AA64MMFR1_HAFDBS_MASK)
822	cmp	x3, #1
823	b.ne	1f
824	orr 	x2, x2, #(TCR_HA)
825	b	2f
8261:
827	cmp	x3, #2
828	b.ne	2f
829	orr 	x2, x2, #(TCR_HA | TCR_HD)
8302:
831	msr	tcr_el1, x2
832
833	/*
834	 * Setup SCTLR.
835	 */
836	ldr	x2, sctlr_set
837	ldr	x3, sctlr_clear
838	mrs	x1, sctlr_el1
839	bic	x1, x1, x3	/* Clear the required bits */
840	orr	x1, x1, x2	/* Set the required bits */
841	msr	sctlr_el1, x1
842	isb
843
844	ret
845
846	.align 3
847mair:
848	.quad	MAIR_ATTR(MAIR_DEVICE_nGnRnE, VM_MEMATTR_DEVICE_nGnRnE) | \
849		MAIR_ATTR(MAIR_NORMAL_NC, VM_MEMATTR_UNCACHEABLE)   |	\
850		MAIR_ATTR(MAIR_NORMAL_WB, VM_MEMATTR_WRITE_BACK)    |	\
851		MAIR_ATTR(MAIR_NORMAL_WT, VM_MEMATTR_WRITE_THROUGH) |	\
852		MAIR_ATTR(MAIR_DEVICE_nGnRE, VM_MEMATTR_DEVICE_nGnRE)
853tcr:
854#if PAGE_SIZE == PAGE_SIZE_4K
855#define	TCR_TG	(TCR_TG1_4K | TCR_TG0_4K)
856#elif PAGE_SIZE == PAGE_SIZE_16K
857#define	TCR_TG	(TCR_TG1_16K | TCR_TG0_16K)
858#else
859#error Unsupported page size
860#endif
861
862	.quad (TCR_TxSZ(64 - VIRT_BITS) | TCR_TG | \
863	    TCR_CACHE_ATTRS | TCR_SMP_ATTRS)
864sctlr_set:
865	/* Bits to set */
866	.quad (SCTLR_LSMAOE | SCTLR_nTLSMD | SCTLR_UCI | SCTLR_SPAN | \
867	    SCTLR_nTWE | SCTLR_nTWI | SCTLR_UCT | SCTLR_DZE | \
868	    SCTLR_I | SCTLR_SED | SCTLR_SA0 | SCTLR_SA | SCTLR_C | \
869	    SCTLR_M | SCTLR_CP15BEN)
870sctlr_clear:
871	/* Bits to clear */
872	.quad (SCTLR_EE | SCTLR_E0E | SCTLR_IESB | SCTLR_WXN | SCTLR_UMA | \
873	    SCTLR_ITD | SCTLR_A)
874LEND(start_mmu)
875
876ENTRY(abort)
877	b abort
878END(abort)
879
880.bss
881	.align	PAGE_SHIFT
882initstack:
883	.space	(PAGE_SIZE * KSTACK_PAGES)
884initstack_end:
885
886	.section .init_pagetable, "aw", %nobits
887	.align PAGE_SHIFT
888	/*
889	 * 6 initial tables (in the following order):
890	 *           L2 for kernel (High addresses)
891	 *           L1 for kernel
892	 *           L0 for kernel
893	 *           L1 bootstrap for user   (Low addresses)
894	 *           L0 bootstrap for user
895	 *           L0 for user
896	 */
897	.globl pagetable_l0_ttbr1
898pagetable:
899#if PAGE_SIZE != PAGE_SIZE_4K
900	.space	(PAGE_SIZE * L3_PAGE_COUNT)
901pagetable_l2_ttbr1:
902#endif
903	.space	PAGE_SIZE
904pagetable_l1_ttbr1:
905	.space	PAGE_SIZE
906pagetable_l0_ttbr1:
907	.space	PAGE_SIZE
908pagetable_l2_ttbr0_bootstrap:
909	.space	PAGE_SIZE
910pagetable_l1_ttbr0_bootstrap:
911	.space	PAGE_SIZE
912pagetable_l0_ttbr0_boostrap:
913	.space	PAGE_SIZE
914pagetable_l0_ttbr0:
915	.space	PAGE_SIZE
916pagetable_end:
917
918el2_pagetable:
919	.space	PAGE_SIZE
920
921	.section .rodata, "a", %progbits
922	.globl	aarch32_sigcode
923	.align 2
924aarch32_sigcode:
925	.word 0xe1a0000d	// mov r0, sp
926	.word 0xe2800040	// add r0, r0, #SIGF_UC
927	.word 0xe59f700c	// ldr r7, [pc, #12]
928	.word 0xef000000	// swi #0
929	.word 0xe59f7008	// ldr r7, [pc, #8]
930	.word 0xef000000	// swi #0
931	.word 0xeafffffa	// b . - 16
932	.word SYS_sigreturn
933	.word SYS_exit
934	.align	3
935	.size aarch32_sigcode, . - aarch32_sigcode
936aarch32_esigcode:
937	.data
938	.global sz_aarch32_sigcode
939sz_aarch32_sigcode:
940	.quad aarch32_esigcode - aarch32_sigcode
941