xref: /arm-trusted-firmware/bl2u/aarch32/bl2u_entrypoint.S (revision 91f16700b400a8c0651d24a598fc48ee2997a0d7)
1*91f16700Schasinglulu/*
2*91f16700Schasinglulu * Copyright (c) 2016-2022, ARM Limited and Contributors. All rights reserved.
3*91f16700Schasinglulu *
4*91f16700Schasinglulu * SPDX-License-Identifier: BSD-3-Clause
5*91f16700Schasinglulu */
6*91f16700Schasinglulu
7*91f16700Schasinglulu#include <arch.h>
8*91f16700Schasinglulu#include <asm_macros.S>
9*91f16700Schasinglulu#include <common/bl_common.h>
10*91f16700Schasinglulu
11*91f16700Schasinglulu	.globl	bl2u_vector_table
12*91f16700Schasinglulu	.globl	bl2u_entrypoint
13*91f16700Schasinglulu
14*91f16700Schasinglulu
15*91f16700Schasingluluvector_base bl2u_vector_table
16*91f16700Schasinglulu	b	bl2u_entrypoint
17*91f16700Schasinglulu	b	report_exception	/* Undef */
18*91f16700Schasinglulu	b	report_exception	/* SVC call */
19*91f16700Schasinglulu	b	report_prefetch_abort	/* Prefetch abort */
20*91f16700Schasinglulu	b	report_data_abort	/* Data abort */
21*91f16700Schasinglulu	b	report_exception	/* Reserved */
22*91f16700Schasinglulu	b	report_exception	/* IRQ */
23*91f16700Schasinglulu	b	report_exception	/* FIQ */
24*91f16700Schasinglulu
25*91f16700Schasinglulu
26*91f16700Schasinglulufunc bl2u_entrypoint
27*91f16700Schasinglulu	/*---------------------------------------------
28*91f16700Schasinglulu	 * Save from r1 the extents of the trusted ram
29*91f16700Schasinglulu	 * available to BL2U for future use.
30*91f16700Schasinglulu	 * r0 is not currently used.
31*91f16700Schasinglulu	 * ---------------------------------------------
32*91f16700Schasinglulu	 */
33*91f16700Schasinglulu	mov	r11, r1
34*91f16700Schasinglulu	mov	r10, r2
35*91f16700Schasinglulu
36*91f16700Schasinglulu	/* ---------------------------------------------
37*91f16700Schasinglulu	 * Set the exception vector to something sane.
38*91f16700Schasinglulu	 * ---------------------------------------------
39*91f16700Schasinglulu	 */
40*91f16700Schasinglulu	ldr	r0, =bl2u_vector_table
41*91f16700Schasinglulu	stcopr	r0, VBAR
42*91f16700Schasinglulu	isb
43*91f16700Schasinglulu
44*91f16700Schasinglulu	/* --------------------------------------------------------
45*91f16700Schasinglulu	 * Enable the instruction cache - disable speculative loads
46*91f16700Schasinglulu	 * --------------------------------------------------------
47*91f16700Schasinglulu	 */
48*91f16700Schasinglulu	ldcopr	r0, SCTLR
49*91f16700Schasinglulu	orr	r0, r0, #SCTLR_I_BIT
50*91f16700Schasinglulu	bic	r0, r0, #SCTLR_DSSBS_BIT
51*91f16700Schasinglulu	stcopr	r0, SCTLR
52*91f16700Schasinglulu	isb
53*91f16700Schasinglulu
54*91f16700Schasinglulu	/* ---------------------------------------------
55*91f16700Schasinglulu	 * Since BL2U executes after BL1, it is assumed
56*91f16700Schasinglulu	 * here that BL1 has already has done the
57*91f16700Schasinglulu	 * necessary register initializations.
58*91f16700Schasinglulu	 * ---------------------------------------------
59*91f16700Schasinglulu	 */
60*91f16700Schasinglulu
61*91f16700Schasinglulu	/* ---------------------------------------------
62*91f16700Schasinglulu	 * Invalidate the RW memory used by the BL2U
63*91f16700Schasinglulu	 * image. This includes the data and NOBITS
64*91f16700Schasinglulu	 * sections. This is done to safeguard against
65*91f16700Schasinglulu	 * possible corruption of this memory by dirty
66*91f16700Schasinglulu	 * cache lines in a system cache as a result of
67*91f16700Schasinglulu	 * use by an earlier boot loader stage.
68*91f16700Schasinglulu	 * ---------------------------------------------
69*91f16700Schasinglulu	 */
70*91f16700Schasinglulu	ldr	r0, =__RW_START__
71*91f16700Schasinglulu	ldr	r1, =__RW_END__
72*91f16700Schasinglulu	sub	r1, r1, r0
73*91f16700Schasinglulu	bl	inv_dcache_range
74*91f16700Schasinglulu
75*91f16700Schasinglulu	/* ---------------------------------------------
76*91f16700Schasinglulu	 * Zero out NOBITS sections. There are 2 of them:
77*91f16700Schasinglulu	 *   - the .bss section;
78*91f16700Schasinglulu	 *   - the coherent memory section.
79*91f16700Schasinglulu	 * ---------------------------------------------
80*91f16700Schasinglulu	 */
81*91f16700Schasinglulu	ldr	r0, =__BSS_START__
82*91f16700Schasinglulu	ldr	r1, =__BSS_END__
83*91f16700Schasinglulu	sub 	r1, r1, r0
84*91f16700Schasinglulu	bl	zeromem
85*91f16700Schasinglulu
86*91f16700Schasinglulu	/* --------------------------------------------
87*91f16700Schasinglulu	 * Allocate a stack whose memory will be marked
88*91f16700Schasinglulu	 * as Normal-IS-WBWA when the MMU is enabled.
89*91f16700Schasinglulu	 * There is no risk of reading stale stack
90*91f16700Schasinglulu	 * memory after enabling the MMU as only the
91*91f16700Schasinglulu	 * primary cpu is running at the moment.
92*91f16700Schasinglulu	 * --------------------------------------------
93*91f16700Schasinglulu	 */
94*91f16700Schasinglulu	bl	plat_set_my_stack
95*91f16700Schasinglulu
96*91f16700Schasinglulu	/* ---------------------------------------------
97*91f16700Schasinglulu	 * Initialize the stack protector canary before
98*91f16700Schasinglulu	 * any C code is called.
99*91f16700Schasinglulu	 * ---------------------------------------------
100*91f16700Schasinglulu	 */
101*91f16700Schasinglulu#if STACK_PROTECTOR_ENABLED
102*91f16700Schasinglulu	bl	update_stack_protector_canary
103*91f16700Schasinglulu#endif
104*91f16700Schasinglulu
105*91f16700Schasinglulu	/* ---------------------------------------------
106*91f16700Schasinglulu	 * Perform early platform setup & platform
107*91f16700Schasinglulu	 * specific early arch. setup e.g. mmu setup
108*91f16700Schasinglulu	 * ---------------------------------------------
109*91f16700Schasinglulu	 */
110*91f16700Schasinglulu	mov	r0, r11
111*91f16700Schasinglulu	mov	r1, r10
112*91f16700Schasinglulu	bl	bl2u_early_platform_setup
113*91f16700Schasinglulu	bl	bl2u_plat_arch_setup
114*91f16700Schasinglulu
115*91f16700Schasinglulu	/* ---------------------------------------------
116*91f16700Schasinglulu	 * Jump to main function.
117*91f16700Schasinglulu	 * ---------------------------------------------
118*91f16700Schasinglulu	 */
119*91f16700Schasinglulu	bl	bl2u_main
120*91f16700Schasinglulu
121*91f16700Schasinglulu	/* ---------------------------------------------
122*91f16700Schasinglulu	 * Should never reach this point.
123*91f16700Schasinglulu	 * ---------------------------------------------
124*91f16700Schasinglulu	 */
125*91f16700Schasinglulu	no_ret	plat_panic_handler
126*91f16700Schasinglulu
127*91f16700Schasingluluendfunc bl2u_entrypoint
128