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1 /*
2  * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <string.h>
9 
10 #include <arch.h>
11 #include <arch_features.h>
12 #include <arch_helpers.h>
13 #include <bl31/bl31.h>
14 #include <bl31/ehf.h>
15 #include <common/bl_common.h>
16 #include <common/debug.h>
17 #include <common/runtime_svc.h>
18 #include <drivers/console.h>
19 #include <lib/el3_runtime/context_mgmt.h>
20 #include <lib/pmf/pmf.h>
21 #include <lib/runtime_instr.h>
22 #include <plat/common/platform.h>
23 #include <services/std_svc.h>
24 
25 #if ENABLE_RUNTIME_INSTRUMENTATION
26 PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
27 	RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
28 #endif
29 
30 /*******************************************************************************
31  * This function pointer is used to initialise the BL32 image. It's initialized
32  * by SPD calling bl31_register_bl32_init after setting up all things necessary
33  * for SP execution. In cases where both SPD and SP are absent, or when SPD
34  * finds it impossible to execute SP, this pointer is left as NULL
35  ******************************************************************************/
36 static int32_t (*bl32_init)(void);
37 
38 /*******************************************************************************
39  * Variable to indicate whether next image to execute after BL31 is BL33
40  * (non-secure & default) or BL32 (secure).
41  ******************************************************************************/
42 static uint32_t next_image_type = NON_SECURE;
43 
44 #ifdef SUPPORT_UNKNOWN_MPID
45 /*
46  * Flag to know whether an unsupported MPID has been detected. To avoid having it
47  * landing on the .bss section, it is initialized to a non-zero value, this way
48  * we avoid potential WAW hazards during system bring up.
49  * */
50 volatile uint32_t unsupported_mpid_flag = 1;
51 #endif
52 
53 /*
54  * Implement the ARM Standard Service function to get arguments for a
55  * particular service.
56  */
get_arm_std_svc_args(unsigned int svc_mask)57 uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
58 {
59 	/* Setup the arguments for PSCI Library */
60 	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
61 
62 	/* PSCI is the only ARM Standard Service implemented */
63 	assert(svc_mask == PSCI_FID_MASK);
64 
65 	return (uintptr_t)&psci_args;
66 }
67 
68 /*******************************************************************************
69  * Simple function to initialise all BL31 helper libraries.
70  ******************************************************************************/
bl31_lib_init(void)71 void __init bl31_lib_init(void)
72 {
73 	cm_init();
74 }
75 
76 /*******************************************************************************
77  * Setup function for BL31.
78  ******************************************************************************/
bl31_setup(u_register_t arg0,u_register_t arg1,u_register_t arg2,u_register_t arg3)79 void bl31_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
80 		u_register_t arg3)
81 {
82 	/* Perform early platform-specific setup */
83 	bl31_early_platform_setup2(arg0, arg1, arg2, arg3);
84 
85 	/* Perform late platform-specific setup */
86 	bl31_plat_arch_setup();
87 
88 #if CTX_INCLUDE_PAUTH_REGS
89 	/*
90 	 * Assert that the ARMv8.3-PAuth registers are present or an access
91 	 * fault will be triggered when they are being saved or restored.
92 	 */
93 	assert(is_armv8_3_pauth_present());
94 #endif /* CTX_INCLUDE_PAUTH_REGS */
95 }
96 
97 /*******************************************************************************
98  * BL31 is responsible for setting up the runtime services for the primary cpu
99  * before passing control to the bootloader or an Operating System. This
100  * function calls runtime_svc_init() which initializes all registered runtime
101  * services. The run time services would setup enough context for the core to
102  * switch to the next exception level. When this function returns, the core will
103  * switch to the programmed exception level via an ERET.
104  ******************************************************************************/
bl31_main(void)105 void bl31_main(void)
106 {
107 	NOTICE("BL31: %s\n", version_string);
108 	NOTICE("BL31: %s\n", build_message);
109 
110 #ifdef SUPPORT_UNKNOWN_MPID
111 	if (unsupported_mpid_flag == 0) {
112 		NOTICE("Unsupported MPID detected!\n");
113 	}
114 #endif
115 
116 	/* Perform platform setup in BL31 */
117 	bl31_platform_setup();
118 
119 	/* Initialise helper libraries */
120 	bl31_lib_init();
121 
122 #if EL3_EXCEPTION_HANDLING
123 	INFO("BL31: Initialising Exception Handling Framework\n");
124 	ehf_init();
125 #endif
126 
127 	/* Initialize the runtime services e.g. psci. */
128 	INFO("BL31: Initializing runtime services\n");
129 	runtime_svc_init();
130 
131 	/*
132 	 * All the cold boot actions on the primary cpu are done. We now need to
133 	 * decide which is the next image (BL32 or BL33) and how to execute it.
134 	 * If the SPD runtime service is present, it would want to pass control
135 	 * to BL32 first in S-EL1. In that case, SPD would have registered a
136 	 * function to initialize bl32 where it takes responsibility of entering
137 	 * S-EL1 and returning control back to bl31_main. Once this is done we
138 	 * can prepare entry into BL33 as normal.
139 	 */
140 
141 	/*
142 	 * If SPD had registered an init hook, invoke it.
143 	 */
144 	if (bl32_init != NULL) {
145 		INFO("BL31: Initializing BL32\n");
146 
147 		int32_t rc = (*bl32_init)();
148 
149 		if (rc == 0)
150 			WARN("BL31: BL32 initialization failed\n");
151 	}
152 	/*
153 	 * We are ready to enter the next EL. Prepare entry into the image
154 	 * corresponding to the desired security state after the next ERET.
155 	 */
156 	bl31_prepare_next_image_entry();
157 
158 	console_flush();
159 
160 	/*
161 	 * Perform any platform specific runtime setup prior to cold boot exit
162 	 * from BL31
163 	 */
164 	bl31_plat_runtime_setup();
165 }
166 
167 /*******************************************************************************
168  * Accessor functions to help runtime services decide which image should be
169  * executed after BL31. This is BL33 or the non-secure bootloader image by
170  * default but the Secure payload dispatcher could override this by requesting
171  * an entry into BL32 (Secure payload) first. If it does so then it should use
172  * the same API to program an entry into BL33 once BL32 initialisation is
173  * complete.
174  ******************************************************************************/
bl31_set_next_image_type(uint32_t security_state)175 void bl31_set_next_image_type(uint32_t security_state)
176 {
177 	assert(sec_state_is_valid(security_state));
178 	next_image_type = security_state;
179 }
180 
bl31_get_next_image_type(void)181 uint32_t bl31_get_next_image_type(void)
182 {
183 	return next_image_type;
184 }
185 
186 /*******************************************************************************
187  * This function programs EL3 registers and performs other setup to enable entry
188  * into the next image after BL31 at the next ERET.
189  ******************************************************************************/
bl31_prepare_next_image_entry(void)190 void __init bl31_prepare_next_image_entry(void)
191 {
192 	entry_point_info_t *next_image_info;
193 	uint32_t image_type;
194 
195 #if CTX_INCLUDE_AARCH32_REGS
196 	/*
197 	 * Ensure that the build flag to save AArch32 system registers in CPU
198 	 * context is not set for AArch64-only platforms.
199 	 */
200 	if (el_implemented(1) == EL_IMPL_A64ONLY) {
201 		ERROR("EL1 supports AArch64-only. Please set build flag "
202 				"CTX_INCLUDE_AARCH32_REGS = 0\n");
203 		panic();
204 	}
205 #endif
206 
207 	/* Determine which image to execute next */
208 	image_type = bl31_get_next_image_type();
209 
210 	/* Program EL3 registers to enable entry into the next EL */
211 	next_image_info = bl31_plat_get_next_image_ep_info(image_type);
212 	assert(next_image_info != NULL);
213 	assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr));
214 
215 	INFO("BL31: Preparing for EL3 exit to %s world\n",
216 		(image_type == SECURE) ? "secure" : "normal");
217 	print_entry_point_info(next_image_info);
218 	cm_init_my_context(next_image_info);
219 	cm_prepare_el3_exit(image_type);
220 }
221 
222 /*******************************************************************************
223  * This function initializes the pointer to BL32 init function. This is expected
224  * to be called by the SPD after it finishes all its initialization
225  ******************************************************************************/
bl31_register_bl32_init(int32_t (* func)(void))226 void bl31_register_bl32_init(int32_t (*func)(void))
227 {
228 	bl32_init = func;
229 }
230