1/*
2 * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7#include <arch.h>
8#include <asm_macros.S>
9#include <debug.h>
10
11	.globl	asm_print_str
12	.globl	asm_print_hex
13	.globl	asm_assert
14	.globl	do_panic
15
16/* Since the max decimal input number is 65536 */
17#define MAX_DEC_DIVISOR		10000
18/* The offset to add to get ascii for numerals '0 - 9' */
19#define ASCII_OFFSET_NUM	0x30
20
21#if ENABLE_ASSERTIONS
22.section .rodata.assert_str, "aS"
23assert_msg1:
24	.asciz "ASSERT: File "
25assert_msg2:
26	.asciz " Line "
27
28	/*
29	 * This macro is intended to be used to print the
30	 * line number in decimal. Used by asm_assert macro.
31	 * The max number expected is 65536.
32	 * In: x4 = the decimal to print.
33	 * Clobber: x30, x0, x1, x2, x5, x6
34	 */
35	.macro asm_print_line_dec
36	mov	x6, #10		/* Divide by 10 after every loop iteration */
37	mov	x5, #MAX_DEC_DIVISOR
38dec_print_loop:
39	udiv	x0, x4, x5		/* Get the quotient */
40	msub	x4, x0, x5, x4		/* Find the remainder */
41	add	x0, x0, #ASCII_OFFSET_NUM		/* Convert to ascii */
42	bl	plat_crash_console_putc
43	udiv	x5, x5, x6		/* Reduce divisor */
44	cbnz	x5, dec_print_loop
45	.endm
46
47
48/* ---------------------------------------------------------------------------
49 * Assertion support in assembly.
50 * The below function helps to support assertions in assembly where we do not
51 * have a C runtime stack. Arguments to the function are :
52 * x0 - File name
53 * x1 - Line no
54 * Clobber list : x30, x0, x1, x2, x3, x4, x5, x6.
55 * ---------------------------------------------------------------------------
56 */
57func asm_assert
58#if LOG_LEVEL >= LOG_LEVEL_INFO
59	/*
60	 * Only print the output if LOG_LEVEL is higher or equal to
61	 * LOG_LEVEL_INFO, which is the default value for builds with DEBUG=1.
62	 */
63	mov	x5, x0
64	mov	x6, x1
65	/* Ensure the console is initialized */
66	bl	plat_crash_console_init
67	/* Check if the console is initialized */
68	cbz	x0, _assert_loop
69	/* The console is initialized */
70	adr	x4, assert_msg1
71	bl	asm_print_str
72	mov	x4, x5
73	bl	asm_print_str
74	adr	x4, assert_msg2
75	bl	asm_print_str
76	/* Check if line number higher than max permitted */
77	tst	x6, #~0xffff
78	b.ne	_assert_loop
79	mov	x4, x6
80	asm_print_line_dec
81	bl	plat_crash_console_flush
82_assert_loop:
83#endif /* LOG_LEVEL >= LOG_LEVEL_INFO */
84	no_ret	plat_panic_handler
85endfunc asm_assert
86#endif /* ENABLE_ASSERTIONS */
87
88/*
89 * This function prints a string from address in x4.
90 * In: x4 = pointer to string.
91 * Clobber: x30, x0, x1, x2, x3
92 */
93func asm_print_str
94	mov	x3, x30
951:
96	ldrb	w0, [x4], #0x1
97	cbz	x0, 2f
98	bl	plat_crash_console_putc
99	b	1b
1002:
101	ret	x3
102endfunc asm_print_str
103
104/*
105 * This function prints a hexadecimal number in x4.
106 * In: x4 = the hexadecimal to print.
107 * Clobber: x30, x0 - x3, x5
108 */
109func asm_print_hex
110	mov	x3, x30
111	mov	x5, #64  /* No of bits to convert to ascii */
1121:
113	sub	x5, x5, #4
114	lsrv	x0, x4, x5
115	and	x0, x0, #0xf
116	cmp	x0, #0xA
117	b.lo	2f
118	/* Add by 0x27 in addition to ASCII_OFFSET_NUM
119	 * to get ascii for characters 'a - f'.
120	 */
121	add	x0, x0, #0x27
1222:
123	add	x0, x0, #ASCII_OFFSET_NUM
124	bl	plat_crash_console_putc
125	cbnz	x5, 1b
126	ret	x3
127endfunc asm_print_hex
128
129	/***********************************************************
130	 * The common implementation of do_panic for all BL stages
131	 ***********************************************************/
132
133.section .rodata.panic_str, "aS"
134	panic_msg: .asciz "PANIC at PC : 0x"
135
136/* ---------------------------------------------------------------------------
137 * do_panic assumes that it is invoked from a C Runtime Environment ie a
138 * valid stack exists. This call will not return.
139 * Clobber list : if CRASH_REPORTING is not enabled then x30, x0 - x6
140 * ---------------------------------------------------------------------------
141 */
142
143/* This is for the non el3 BL stages to compile through */
144	.weak el3_panic
145
146func do_panic
147#if CRASH_REPORTING
148	str	x0, [sp, #-0x10]!
149	mrs	x0, currentel
150	ubfx	x0, x0, #2, #2
151	cmp	x0, #0x3
152	ldr	x0, [sp], #0x10
153	b.eq	el3_panic
154#endif
155
156panic_common:
157/*
158 * el3_panic will be redefined by the BL31
159 * crash reporting mechanism (if enabled)
160 */
161el3_panic:
162	mov	x6, x30
163	bl	plat_crash_console_init
164	/* Check if the console is initialized */
165	cbz	x0, _panic_handler
166	/* The console is initialized */
167	adr	x4, panic_msg
168	bl	asm_print_str
169	mov	x4, x6
170	/* The panic location is lr -4 */
171	sub	x4, x4, #4
172	bl	asm_print_hex
173
174	bl	plat_crash_console_flush
175
176_panic_handler:
177	/* Pass to plat_panic_handler the address from where el3_panic was
178	 * called, not the address of the call from el3_panic. */
179	mov	x30, x6
180	b	plat_panic_handler
181endfunc do_panic
182