xref: /freebsd/sys/arm64/arm64/locore.S (revision 005cca8361a4932d03bd93fefa998fff69a1e136)
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
150	/* trace back starts here */
151	mov	fp, #0
152	/* Branch to C code */
153	bl	initarm
154	/* We are done with the boot params */
155	add	sp, sp, #BOOTPARAMS_SIZE
156
157	/*
158	 * Enable pointer authentication in the kernel. We set the keys for
159	 * thread0 in initarm so have to wait until it returns to enable it.
160	 * If we were to enable it in initarm then any authentication when
161	 * returning would fail as it was called with pointer authentication
162	 * disabled.
163	 */
164	bl	ptrauth_start
165
166	bl	mi_startup
167
168	/* We should not get here */
169	brk	0
170
171	.align 3
172.Lvirtdone:
173	.quad	virtdone
174.Lbss:
175	.quad	__bss_start
176.Lend:
177	.quad	__bss_end
178END(_start)
179
180#ifdef SMP
181/*
182 * mpentry(unsigned long)
183 *
184 * Called by a core when it is being brought online.
185 * The data in x0 is passed straight to init_secondary.
186 */
187ENTRY(mpentry)
188	/* Disable interrupts */
189	msr	daifset, #DAIF_INTR
190
191	/* Drop to EL1 */
192	bl	drop_to_el1
193
194	/* Set the context id */
195	msr	contextidr_el1, xzr
196
197	/* Load the kernel page table */
198	adrp	x24, pagetable_l0_ttbr1
199	add	x24, x24, :lo12:pagetable_l0_ttbr1
200	/* Load the identity page table */
201	adrp	x27, pagetable_l0_ttbr0_boostrap
202	add	x27, x27, :lo12:pagetable_l0_ttbr0_boostrap
203
204	/* Enable the mmu */
205	bl	start_mmu
206
207	/* Load the new ttbr0 pagetable */
208	adrp	x27, pagetable_l0_ttbr0
209	add	x27, x27, :lo12:pagetable_l0_ttbr0
210
211	/* Jump to the virtual address space */
212	ldr	x15, =mp_virtdone
213	br	x15
214
215mp_virtdone:
216	/* Start using the AP boot stack */
217	ldr	x4, =bootstack
218	ldr	x4, [x4]
219	mov	sp, x4
220
221#if defined(PERTHREAD_SSP)
222	/* Set sp_el0 to the boot canary for early per-thread SSP to work */
223	adrp	x15, boot_canary
224	add	x15, x15, :lo12:boot_canary
225	msr	sp_el0, x15
226#endif
227
228	/* Load the kernel ttbr0 pagetable */
229	msr	ttbr0_el1, x27
230	isb
231
232	/* Invalidate the TLB */
233	tlbi	vmalle1
234	dsb	sy
235	isb
236
237	b	init_secondary
238END(mpentry)
239#endif
240
241/*
242 * If we are started in EL2, configure the required hypervisor
243 * registers and drop to EL1.
244 */
245LENTRY(drop_to_el1)
246	mrs	x23, CurrentEL
247	lsr	x23, x23, #2
248	cmp	x23, #0x2
249	b.eq	1f
250	ret
2511:
252	/*
253	 * Disable the MMU. If the HCR_EL2.E2H field is set we will clear it
254	 * which may break address translation.
255	 */
256	dsb	sy
257	mrs	x2, sctlr_el2
258	bic	x2, x2, SCTLR_M
259	msr	sctlr_el2, x2
260	isb
261
262	/* Configure the Hypervisor */
263	ldr	x2, =(HCR_RW | HCR_APK | HCR_API)
264	msr	hcr_el2, x2
265
266	/* Stash value of HCR_EL2 for later */
267	isb
268	mrs	x4, hcr_el2
269
270	/* Load the Virtualization Process ID Register */
271	mrs	x2, midr_el1
272	msr	vpidr_el2, x2
273
274	/* Load the Virtualization Multiprocess ID Register */
275	mrs	x2, mpidr_el1
276	msr	vmpidr_el2, x2
277
278	/* Set the bits that need to be 1 in sctlr_el1 */
279	ldr	x2, .Lsctlr_res1
280	msr	sctlr_el1, x2
281
282	/*
283	 * On some hardware, e.g., Apple M1, we can't clear E2H, so make sure we
284	 * don't trap to EL2 for SIMD register usage to have at least a
285	 * minimally usable system.
286	 */
287	tst	x4, #HCR_E2H
288	mov	x3, #CPTR_RES1	/* HCR_E2H == 0 */
289	mov	x4, #CPTR_FPEN	/* HCR_E2H == 1 */
290	csel	x2, x3, x4, eq
291	msr	cptr_el2, x2
292
293	/* Don't trap to EL2 for CP15 traps */
294	msr	hstr_el2, xzr
295
296	/* Enable access to the physical timers at EL1 */
297	mrs	x2, cnthctl_el2
298	orr	x2, x2, #(CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN)
299	msr	cnthctl_el2, x2
300
301	/* Set the counter offset to a known value */
302	msr	cntvoff_el2, xzr
303
304	/* Hypervisor trap functions */
305	adrp	x2, hyp_stub_vectors
306	add	x2, x2, :lo12:hyp_stub_vectors
307	msr	vbar_el2, x2
308
309	/* Zero vttbr_el2 so a hypervisor can tell the host and guest apart */
310	msr	vttbr_el2, xzr
311
312	mov	x2, #(PSR_F | PSR_I | PSR_A | PSR_D | PSR_M_EL1h)
313	msr	spsr_el2, x2
314
315	/* Configure GICv3 CPU interface */
316	mrs	x2, id_aa64pfr0_el1
317	/* Extract GIC bits from the register */
318	ubfx	x2, x2, #ID_AA64PFR0_GIC_SHIFT, #ID_AA64PFR0_GIC_BITS
319	/* GIC[3:0] == 0001 - GIC CPU interface via special regs. supported */
320	cmp	x2, #(ID_AA64PFR0_GIC_CPUIF_EN >> ID_AA64PFR0_GIC_SHIFT)
321	b.ne	2f
322
323	mrs	x2, icc_sre_el2
324	orr	x2, x2, #ICC_SRE_EL2_EN	/* Enable access from insecure EL1 */
325	orr	x2, x2, #ICC_SRE_EL2_SRE	/* Enable system registers */
326	msr	icc_sre_el2, x2
3272:
328
329	/* Set the address to return to our return address */
330	msr	elr_el2, x30
331	isb
332
333	eret
334
335	.align 3
336.Lsctlr_res1:
337	.quad SCTLR_RES1
338LEND(drop_to_el1)
339
340/*
341 * Get the delta between the physical address we were loaded to and the
342 * virtual address we expect to run from. This is used when building the
343 * initial page table.
344 */
345LENTRY(get_virt_delta)
346	/* Load the physical address of virt_map */
347	adrp	x29, virt_map
348	add	x29, x29, :lo12:virt_map
349	/* Load the virtual address of virt_map stored in virt_map */
350	ldr	x28, [x29]
351	/* Find PA - VA as PA' = VA' - VA + PA = VA' + (PA - VA) = VA' + x29 */
352	sub	x29, x29, x28
353	/* Find the load address for the kernel */
354	mov	x28, #(KERNBASE)
355	add	x28, x28, x29
356	ret
357
358	.align 3
359virt_map:
360	.quad	virt_map
361LEND(get_virt_delta)
362
363/*
364 * This builds the page tables containing the identity map, and the kernel
365 * virtual map.
366 *
367 * It relys on:
368 *  We were loaded to an address that is on a 2MiB boundary
369 *  All the memory must not cross a 1GiB boundaty
370 *  x28 contains the physical address we were loaded from
371 *
372 * TODO: This is out of date.
373 *  There are at least 5 pages before that address for the page tables
374 *   The pages used are:
375 *    - The Kernel L2 table
376 *    - The Kernel L1 table
377 *    - The Kernel L0 table             (TTBR1)
378 *    - The identity (PA = VA) L1 table
379 *    - The identity (PA = VA) L0 table (TTBR0)
380 */
381LENTRY(create_pagetables)
382	/* Save the Link register */
383	mov	x5, x30
384
385	/* Clean the page table */
386	adrp	x6, pagetable
387	add	x6, x6, :lo12:pagetable
388	mov	x26, x6
389	adrp	x27, pagetable_end
390	add	x27, x27, :lo12:pagetable_end
3911:
392	stp	xzr, xzr, [x6], #16
393	stp	xzr, xzr, [x6], #16
394	stp	xzr, xzr, [x6], #16
395	stp	xzr, xzr, [x6], #16
396	cmp	x6, x27
397	b.lo	1b
398
399	/*
400	 * Build the TTBR1 maps.
401	 */
402
403	/* Find the size of the kernel */
404	mov	x6, #(KERNBASE)
405
406#if defined(LINUX_BOOT_ABI)
407	/* X19 is used as 'map FDT data' flag */
408	mov	x19, xzr
409
410	/* No modules or FDT pointer ? */
411	cbz	x0, booti_no_fdt
412
413	/*
414	 * Test if x0 points to modules descriptor(virtual address) or
415	 * to FDT (physical address)
416	 */
417	cmp	x0, x6		/* x6 is #(KERNBASE) */
418	b.lo	booti_fdt
419#endif
420
421	/* Booted with modules pointer */
422	/* Find modulep - begin */
423	sub	x8, x0, x6
424	/*
425	 * Add space for the module data. When PAGE_SIZE is 4k this will
426	 * add at least 2 level 2 blocks (2 * 2MiB). When PAGE_SIZE is
427	 * larger it will be at least as large as we use smaller level 3
428	 * pages.
429	 */
430	ldr	x7, =((6 * 1024 * 1024) - 1)
431	add	x8, x8, x7
432	b	common
433
434#if defined(LINUX_BOOT_ABI)
435booti_fdt:
436	/* Booted by U-Boot booti with FDT data */
437	/* Set 'map FDT data' flag */
438	mov	x19, #1
439
440booti_no_fdt:
441	/* Booted by U-Boot booti without FTD data */
442	/* Find the end - begin */
443	ldr     x7, .Lend
444	sub     x8, x7, x6
445
446	/*
447	 * Add one 2MiB page for copy of FDT data (maximum FDT size),
448	 * one for metadata and round up
449	 */
450	ldr	x7, =(3 * L2_SIZE - 1)
451	add	x8, x8, x7
452#endif
453
454common:
455#if PAGE_SIZE != PAGE_SIZE_4K
456	/*
457	 * Create L3 pages. The kernel will be loaded at a 2M aligned
458	 * address, however L2 blocks are too large when the page size is
459	 * not 4k to map the kernel with such an aligned address. However,
460	 * when the page size is larger than 4k, L2 blocks are too large to
461	 * map the kernel with such an alignment.
462	 */
463
464	/* Get the number of l3 pages to allocate, rounded down */
465	lsr	x10, x8, #(L3_SHIFT)
466
467	/* Create the kernel space L2 table */
468	mov	x6, x26
469	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
470	mov	x8, #(KERNBASE)
471	mov	x9, x28
472	bl	build_l3_page_pagetable
473
474	/* Move to the l2 table */
475	ldr	x9, =(PAGE_SIZE * L3_PAGE_COUNT)
476	add	x26, x26, x9
477
478	/* Link the l2 -> l3 table */
479	mov	x9, x6
480	mov	x6, x26
481	bl	link_l2_pagetable
482#else
483	/* Get the number of l2 pages to allocate, rounded down */
484	lsr	x10, x8, #(L2_SHIFT)
485
486	/* Create the kernel space L2 table */
487	mov	x6, x26
488	mov	x7, #(ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
489	mov	x8, #(KERNBASE)
490	mov	x9, x28
491	bl	build_l2_block_pagetable
492#endif
493
494	/* Move to the l1 table */
495	add	x26, x26, #PAGE_SIZE
496
497	/* Link the l1 -> l2 table */
498	mov	x9, x6
499	mov	x6, x26
500	bl	link_l1_pagetable
501
502	/* Move to the l0 table */
503	add	x24, x26, #PAGE_SIZE
504
505	/* Link the l0 -> l1 table */
506	mov	x9, x6
507	mov	x6, x24
508	mov	x10, #1
509	bl	link_l0_pagetable
510
511	/*
512	 * Build the TTBR0 maps.  As TTBR0 maps, they must specify ATTR_S1_nG.
513	 * They are only needed early on, so the VA = PA map is uncached.
514	 */
515	add	x27, x24, #PAGE_SIZE
516
517	mov	x6, x27		/* The initial page table */
518
519	/* Create the VA = PA map */
520	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
521	adrp	x16, _start
522	and	x16, x16, #(~L2_OFFSET)
523	mov	x9, x16		/* PA start */
524	mov	x8, x16		/* VA start (== PA start) */
525	mov	x10, #1
526	bl	build_l2_block_pagetable
527
528#if defined(SOCDEV_PA)
529	/* Create a table for the UART */
530	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_DEVICE))
531	ldr	x9, =(L2_SIZE)
532	add	x16, x16, x9	/* VA start */
533	mov	x8, x16
534
535	/* Store the socdev virtual address */
536	add	x17, x8, #(SOCDEV_PA & L2_OFFSET)
537	adrp	x9, socdev_va
538	str	x17, [x9, :lo12:socdev_va]
539
540	mov	x9, #(SOCDEV_PA & ~L2_OFFSET)	/* PA start */
541	mov	x10, #1
542	bl	build_l2_block_pagetable
543#endif
544
545#if defined(LINUX_BOOT_ABI)
546	/* Map FDT data ? */
547	cbz	x19, 1f
548
549	/* Create the mapping for FDT data (2 MiB max) */
550	mov	x7, #(ATTR_S1_nG | ATTR_S1_IDX(VM_MEMATTR_WRITE_BACK))
551	ldr	x9, =(L2_SIZE)
552	add	x16, x16, x9	/* VA start */
553	mov	x8, x16
554	mov	x9, x0			/* PA start */
555	/* Update the module pointer to point at the allocated memory */
556	and	x0, x0, #(L2_OFFSET)	/* Keep the lower bits */
557	add	x0, x0, x8		/* Add the aligned virtual address */
558
559	mov	x10, #1
560	bl	build_l2_block_pagetable
561
5621:
563#endif
564
565	/* Move to the l1 table */
566	add	x27, x27, #PAGE_SIZE
567
568	/* Link the l1 -> l2 table */
569	mov	x9, x6
570	mov	x6, x27
571	bl	link_l1_pagetable
572
573	/* Move to the l0 table */
574	add	x27, x27, #PAGE_SIZE
575
576	/* Link the l0 -> l1 table */
577	mov	x9, x6
578	mov	x6, x27
579	mov	x10, #1
580	bl	link_l0_pagetable
581
582	/* Restore the Link register */
583	mov	x30, x5
584	ret
585LEND(create_pagetables)
586
587/*
588 * Builds an L0 -> L1 table descriptor
589 *
590 *  x6  = L0 table
591 *  x8  = Virtual Address
592 *  x9  = L1 PA (trashed)
593 *  x10 = Entry count (trashed)
594 *  x11, x12 and x13 are trashed
595 */
596LENTRY(link_l0_pagetable)
597	/*
598	 * Link an L0 -> L1 table entry.
599	 */
600	/* Find the table index */
601	lsr	x11, x8, #L0_SHIFT
602	and	x11, x11, #L0_ADDR_MASK
603
604	/* Build the L0 block entry */
605	mov	x12, #L0_TABLE
606	orr	x12, x12, #(TATTR_UXN_TABLE | TATTR_AP_TABLE_NO_EL0)
607
608	/* Only use the output address bits */
609	lsr	x9, x9, #PAGE_SHIFT
6101:	orr	x13, x12, x9, lsl #PAGE_SHIFT
611
612	/* Store the entry */
613	str	x13, [x6, x11, lsl #3]
614
615	sub	x10, x10, #1
616	add	x11, x11, #1
617	add	x9, x9, #1
618	cbnz	x10, 1b
619
620	ret
621LEND(link_l0_pagetable)
622
623/*
624 * Builds an L1 -> L2 table descriptor
625 *
626 *  x6  = L1 table
627 *  x8  = Virtual Address
628 *  x9  = L2 PA (trashed)
629 *  x11, x12 and x13 are trashed
630 */
631LENTRY(link_l1_pagetable)
632	/*
633	 * Link an L1 -> L2 table entry.
634	 */
635	/* Find the table index */
636	lsr	x11, x8, #L1_SHIFT
637	and	x11, x11, #Ln_ADDR_MASK
638
639	/* Build the L1 block entry */
640	mov	x12, #L1_TABLE
641
642	/* Only use the output address bits */
643	lsr	x9, x9, #PAGE_SHIFT
644	orr	x13, x12, x9, lsl #PAGE_SHIFT
645
646	/* Store the entry */
647	str	x13, [x6, x11, lsl #3]
648
649	ret
650LEND(link_l1_pagetable)
651
652/*
653 * Builds count 2 MiB page table entry
654 *  x6  = L2 table
655 *  x7  = Block attributes
656 *  x8  = VA start
657 *  x9  = PA start (trashed)
658 *  x10 = Entry count (trashed)
659 *  x11, x12 and x13 are trashed
660 */
661LENTRY(build_l2_block_pagetable)
662	/*
663	 * Build the L2 table entry.
664	 */
665	/* Find the table index */
666	lsr	x11, x8, #L2_SHIFT
667	and	x11, x11, #Ln_ADDR_MASK
668
669	/* Build the L2 block entry */
670	orr	x12, x7, #L2_BLOCK
671	orr	x12, x12, #(ATTR_DEFAULT)
672	orr	x12, x12, #(ATTR_S1_UXN)
673
674	/* Only use the output address bits */
675	lsr	x9, x9, #L2_SHIFT
676
677	/* Set the physical address for this virtual address */
6781:	orr	x13, x12, x9, lsl #L2_SHIFT
679
680	/* Store the entry */
681	str	x13, [x6, x11, lsl #3]
682
683	sub	x10, x10, #1
684	add	x11, x11, #1
685	add	x9, x9, #1
686	cbnz	x10, 1b
687
688	ret
689LEND(build_l2_block_pagetable)
690
691#if PAGE_SIZE != PAGE_SIZE_4K
692/*
693 * Builds an L2 -> L3 table descriptor
694 *
695 *  x6  = L2 table
696 *  x8  = Virtual Address
697 *  x9  = L3 PA (trashed)
698 *  x11, x12 and x13 are trashed
699 */
700LENTRY(link_l2_pagetable)
701	/*
702	 * Link an L2 -> L3 table entry.
703	 */
704	/* Find the table index */
705	lsr	x11, x8, #L2_SHIFT
706	and	x11, x11, #Ln_ADDR_MASK
707
708	/* Build the L1 block entry */
709	mov	x12, #L2_TABLE
710
711	/* Only use the output address bits */
712	lsr	x9, x9, #PAGE_SHIFT
713	orr	x13, x12, x9, lsl #PAGE_SHIFT
714
715	/* Store the entry */
716	str	x13, [x6, x11, lsl #3]
717
718	ret
719LEND(link_l2_pagetable)
720
721/*
722 * Builds count level 3 page table entries
723 *  x6  = L3 table
724 *  x7  = Block attributes
725 *  x8  = VA start
726 *  x9  = PA start (trashed)
727 *  x10 = Entry count (trashed)
728 *  x11, x12 and x13 are trashed
729 */
730LENTRY(build_l3_page_pagetable)
731	/*
732	 * Build the L3 table entry.
733	 */
734	/* Find the table index */
735	lsr	x11, x8, #L3_SHIFT
736	and	x11, x11, #Ln_ADDR_MASK
737
738	/* Build the L3 page entry */
739	orr	x12, x7, #L3_PAGE
740	orr	x12, x12, #(ATTR_DEFAULT)
741	orr	x12, x12, #(ATTR_S1_UXN)
742
743	/* Only use the output address bits */
744	lsr	x9, x9, #L3_SHIFT
745
746	/* Set the physical address for this virtual address */
7471:	orr	x13, x12, x9, lsl #L3_SHIFT
748
749	/* Store the entry */
750	str	x13, [x6, x11, lsl #3]
751
752	sub	x10, x10, #1
753	add	x11, x11, #1
754	add	x9, x9, #1
755	cbnz	x10, 1b
756
757	ret
758LEND(build_l3_page_pagetable)
759#endif
760
761LENTRY(start_mmu)
762	dsb	sy
763
764	/* Load the exception vectors */
765	ldr	x2, =exception_vectors
766	msr	vbar_el1, x2
767
768	/* Load ttbr0 and ttbr1 */
769	msr	ttbr0_el1, x27
770	msr	ttbr1_el1, x24
771	isb
772
773	/* Clear the Monitor Debug System control register */
774	msr	mdscr_el1, xzr
775
776	/* Invalidate the TLB */
777	tlbi	vmalle1is
778	dsb	ish
779	isb
780
781	ldr	x2, mair
782	msr	mair_el1, x2
783
784	/*
785	 * Setup TCR according to the PARange and ASIDBits fields
786	 * from ID_AA64MMFR0_EL1 and the HAFDBS field from the
787	 * ID_AA64MMFR1_EL1.  More precisely, set TCR_EL1.AS
788	 * to 1 only if the ASIDBits field equals 0b0010.
789	 */
790	ldr	x2, tcr
791	mrs	x3, id_aa64mmfr0_el1
792
793	/* Copy the bottom 3 bits from id_aa64mmfr0_el1 into TCR.IPS */
794	bfi	x2, x3, #(TCR_IPS_SHIFT), #(TCR_IPS_WIDTH)
795	and	x3, x3, #(ID_AA64MMFR0_ASIDBits_MASK)
796
797	/* Check if the HW supports 16 bit ASIDS */
798	cmp	x3, #(ID_AA64MMFR0_ASIDBits_16)
799	/* If so x3 == 1, else x3 == 0 */
800	cset	x3, eq
801	/* Set TCR.AS with x3 */
802	bfi	x2, x3, #(TCR_ASID_SHIFT), #(TCR_ASID_WIDTH)
803
804	/*
805	 * Check if the HW supports access flag and dirty state updates,
806	 * and set TCR_EL1.HA and TCR_EL1.HD accordingly.
807	 */
808	mrs	x3, id_aa64mmfr1_el1
809	and	x3, x3, #(ID_AA64MMFR1_HAFDBS_MASK)
810	cmp	x3, #1
811	b.ne	1f
812	orr 	x2, x2, #(TCR_HA)
813	b	2f
8141:
815	cmp	x3, #2
816	b.ne	2f
817	orr 	x2, x2, #(TCR_HA | TCR_HD)
8182:
819	msr	tcr_el1, x2
820
821	/*
822	 * Setup SCTLR.
823	 */
824	ldr	x2, sctlr_set
825	ldr	x3, sctlr_clear
826	mrs	x1, sctlr_el1
827	bic	x1, x1, x3	/* Clear the required bits */
828	orr	x1, x1, x2	/* Set the required bits */
829	msr	sctlr_el1, x1
830	isb
831
832	ret
833
834	.align 3
835mair:
836	.quad	MAIR_ATTR(MAIR_DEVICE_nGnRnE, VM_MEMATTR_DEVICE_nGnRnE) | \
837		MAIR_ATTR(MAIR_NORMAL_NC, VM_MEMATTR_UNCACHEABLE)   |	\
838		MAIR_ATTR(MAIR_NORMAL_WB, VM_MEMATTR_WRITE_BACK)    |	\
839		MAIR_ATTR(MAIR_NORMAL_WT, VM_MEMATTR_WRITE_THROUGH) |	\
840		MAIR_ATTR(MAIR_DEVICE_nGnRE, VM_MEMATTR_DEVICE_nGnRE)
841tcr:
842#if PAGE_SIZE == PAGE_SIZE_4K
843#define	TCR_TG	(TCR_TG1_4K | TCR_TG0_4K)
844#elif PAGE_SIZE == PAGE_SIZE_16K
845#define	TCR_TG	(TCR_TG1_16K | TCR_TG0_16K)
846#else
847#error Unsupported page size
848#endif
849
850	.quad (TCR_TxSZ(64 - VIRT_BITS) | TCR_TG | \
851	    TCR_CACHE_ATTRS | TCR_SMP_ATTRS)
852sctlr_set:
853	/* Bits to set */
854	.quad (SCTLR_LSMAOE | SCTLR_nTLSMD | SCTLR_UCI | SCTLR_SPAN | \
855	    SCTLR_nTWE | SCTLR_nTWI | SCTLR_UCT | SCTLR_DZE | \
856	    SCTLR_I | SCTLR_SED | SCTLR_SA0 | SCTLR_SA | SCTLR_C | \
857	    SCTLR_M | SCTLR_CP15BEN)
858sctlr_clear:
859	/* Bits to clear */
860	.quad (SCTLR_EE | SCTLR_E0E | SCTLR_IESB | SCTLR_WXN | SCTLR_UMA | \
861	    SCTLR_ITD | SCTLR_A)
862LEND(start_mmu)
863
864ENTRY(abort)
865	b abort
866END(abort)
867
868	.section .init_pagetable, "aw", %nobits
869	.align PAGE_SHIFT
870	/*
871	 * 6 initial tables (in the following order):
872	 *           L2 for kernel (High addresses)
873	 *           L1 for kernel
874	 *           L0 for kernel
875	 *           L1 bootstrap for user   (Low addresses)
876	 *           L0 bootstrap for user
877	 *           L0 for user
878	 */
879	.globl pagetable_l0_ttbr1
880pagetable:
881#if PAGE_SIZE != PAGE_SIZE_4K
882	.space	(PAGE_SIZE * L3_PAGE_COUNT)
883pagetable_l2_ttbr1:
884#endif
885	.space	PAGE_SIZE
886pagetable_l1_ttbr1:
887	.space	PAGE_SIZE
888pagetable_l0_ttbr1:
889	.space	PAGE_SIZE
890pagetable_l2_ttbr0_bootstrap:
891	.space	PAGE_SIZE
892pagetable_l1_ttbr0_bootstrap:
893	.space	PAGE_SIZE
894pagetable_l0_ttbr0_boostrap:
895	.space	PAGE_SIZE
896pagetable_l0_ttbr0:
897	.space	PAGE_SIZE
898
899pagetable_end:
900
901el2_pagetable:
902	.space	PAGE_SIZE
903
904	.align	4
905initstack:
906	.space	(PAGE_SIZE * KSTACK_PAGES)
907initstack_end:
908
909
910.text
911EENTRY(aarch32_sigcode)
912	.word 0xe1a0000d	// mov r0, sp
913	.word 0xe2800040	// add r0, r0, #SIGF_UC
914	.word 0xe59f700c	// ldr r7, [pc, #12]
915	.word 0xef000000	// swi #0
916	.word 0xe59f7008	// ldr r7, [pc, #8]
917	.word 0xef000000	// swi #0
918	.word 0xeafffffa	// b . - 16
919EEND(aarch32_sigcode)
920	.word SYS_sigreturn
921	.word SYS_exit
922	.align	3
923aarch32_esigcode:
924	.data
925	.global sz_aarch32_sigcode
926sz_aarch32_sigcode:
927	.quad aarch32_esigcode - aarch32_sigcode
928