1 /*
2  * Copyright (c) 2013-2024, 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/build_message.h>
17 #include <common/debug.h>
18 #include <common/feat_detect.h>
19 #include <common/runtime_svc.h>
20 #include <drivers/console.h>
21 #include <lib/bootmarker_capture.h>
22 #include <lib/el3_runtime/context_debug.h>
23 #include <lib/el3_runtime/context_mgmt.h>
24 #include <lib/pmf/pmf.h>
25 #include <lib/runtime_instr.h>
26 #include <plat/common/platform.h>
27 #include <services/std_svc.h>
28 
29 #if ENABLE_RUNTIME_INSTRUMENTATION
30 	PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
31 		RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
32 #endif
33 
34 #if ENABLE_RUNTIME_INSTRUMENTATION
35 	PMF_REGISTER_SERVICE(bl_svc, PMF_RT_INSTR_SVC_ID,
36 		BL_TOTAL_IDS, PMF_DUMP_ENABLE)
37 #endif
38 
39 /*******************************************************************************
40  * This function pointer is used to initialise the BL32 image. It's initialized
41  * by SPD calling bl31_register_bl32_init after setting up all things necessary
42  * for SP execution. In cases where both SPD and SP are absent, or when SPD
43  * finds it impossible to execute SP, this pointer is left as NULL
44  ******************************************************************************/
45 static int32_t (*bl32_init)(void);
46 
47 /*****************************************************************************
48  * Function used to initialise RMM if RME is enabled
49  *****************************************************************************/
50 #if ENABLE_RME
51 static int32_t (*rmm_init)(void);
52 #endif
53 
54 /*******************************************************************************
55  * Variable to indicate whether next image to execute after BL31 is BL33
56  * (non-secure & default) or BL32 (secure).
57  ******************************************************************************/
58 static uint32_t next_image_type = NON_SECURE;
59 
60 #ifdef SUPPORT_UNKNOWN_MPID
61 /*
62  * Flag to know whether an unsupported MPID has been detected. To avoid having it
63  * landing on the .bss section, it is initialized to a non-zero value, this way
64  * we avoid potential WAW hazards during system bring up.
65  * */
66 volatile uint32_t unsupported_mpid_flag = 1;
67 #endif
68 
69 /*
70  * Implement the ARM Standard Service function to get arguments for a
71  * particular service.
72  */
get_arm_std_svc_args(unsigned int svc_mask)73 uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
74 {
75 	/* Setup the arguments for PSCI Library */
76 	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
77 
78 	/* PSCI is the only ARM Standard Service implemented */
79 	assert(svc_mask == PSCI_FID_MASK);
80 
81 	return (uintptr_t)&psci_args;
82 }
83 
84 /*******************************************************************************
85  * Simple function to initialise all BL31 helper libraries.
86  ******************************************************************************/
bl31_lib_init(void)87 static void __init bl31_lib_init(void)
88 {
89 	cm_init();
90 }
91 
92 /*******************************************************************************
93  * Setup function for BL31.
94  ******************************************************************************/
bl31_setup(u_register_t arg0,u_register_t arg1,u_register_t arg2,u_register_t arg3)95 void bl31_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
96 		u_register_t arg3)
97 {
98 	/* Enable early console if EARLY_CONSOLE flag is enabled */
99 	plat_setup_early_console();
100 
101 	/* Perform early platform-specific setup */
102 	bl31_early_platform_setup2(arg0, arg1, arg2, arg3);
103 
104 	/* Perform late platform-specific setup */
105 	bl31_plat_arch_setup();
106 
107 #if CTX_INCLUDE_PAUTH_REGS
108 	/*
109 	 * Assert that the ARMv8.3-PAuth registers are present or an access
110 	 * fault will be triggered when they are being saved or restored.
111 	 */
112 	assert(is_armv8_3_pauth_present());
113 #endif /* CTX_INCLUDE_PAUTH_REGS */
114 
115 	/* Prints context_memory allocated for all the security states */
116 	report_ctx_memory_usage();
117 }
118 
119 /*******************************************************************************
120  * BL31 is responsible for setting up the runtime services for the primary cpu
121  * before passing control to the bootloader or an Operating System. This
122  * function calls runtime_svc_init() which initializes all registered runtime
123  * services. The run time services would setup enough context for the core to
124  * switch to the next exception level. When this function returns, the core will
125  * switch to the programmed exception level via an ERET.
126  ******************************************************************************/
bl31_main(void)127 void bl31_main(void)
128 {
129 	/* Init registers that never change for the lifetime of TF-A */
130 	cm_manage_extensions_el3();
131 
132 	/* Init per-world context registers for non-secure world */
133 	manage_extensions_nonsecure_per_world();
134 
135 	NOTICE("BL31: %s\n", build_version_string);
136 	NOTICE("BL31: %s\n", build_message);
137 
138 #if FEATURE_DETECTION
139 	/* Detect if features enabled during compilation are supported by PE. */
140 	detect_arch_features();
141 #endif /* FEATURE_DETECTION */
142 
143 #if ENABLE_RUNTIME_INSTRUMENTATION
144 	PMF_CAPTURE_TIMESTAMP(bl_svc, BL31_ENTRY, PMF_CACHE_MAINT);
145 #endif
146 
147 #ifdef SUPPORT_UNKNOWN_MPID
148 	if (unsupported_mpid_flag == 0) {
149 		NOTICE("Unsupported MPID detected!\n");
150 	}
151 #endif
152 
153 	/* Perform platform setup in BL31 */
154 	bl31_platform_setup();
155 
156 	/* Initialise helper libraries */
157 	bl31_lib_init();
158 
159 #if EL3_EXCEPTION_HANDLING
160 	INFO("BL31: Initialising Exception Handling Framework\n");
161 	ehf_init();
162 #endif
163 
164 	/* Initialize the runtime services e.g. psci. */
165 	INFO("BL31: Initializing runtime services\n");
166 	runtime_svc_init();
167 
168 	/*
169 	 * All the cold boot actions on the primary cpu are done. We now need to
170 	 * decide which is the next image and how to execute it.
171 	 * If the SPD runtime service is present, it would want to pass control
172 	 * to BL32 first in S-EL1. In that case, SPD would have registered a
173 	 * function to initialize bl32 where it takes responsibility of entering
174 	 * S-EL1 and returning control back to bl31_main. Similarly, if RME is
175 	 * enabled and a function is registered to initialize RMM, control is
176 	 * transferred to RMM in R-EL2. After RMM initialization, control is
177 	 * returned back to bl31_main. Once this is done we can prepare entry
178 	 * into BL33 as normal.
179 	 */
180 
181 	/*
182 	 * If SPD had registered an init hook, invoke it.
183 	 */
184 	if (bl32_init != NULL) {
185 		INFO("BL31: Initializing BL32\n");
186 
187 		console_flush();
188 		int32_t rc = (*bl32_init)();
189 
190 		if (rc == 0) {
191 			WARN("BL31: BL32 initialization failed\n");
192 		}
193 	}
194 
195 	/*
196 	 * If RME is enabled and init hook is registered, initialize RMM
197 	 * in R-EL2.
198 	 */
199 #if ENABLE_RME
200 	if (rmm_init != NULL) {
201 		INFO("BL31: Initializing RMM\n");
202 
203 		console_flush();
204 		int32_t rc = (*rmm_init)();
205 
206 		if (rc == 0) {
207 			WARN("BL31: RMM initialization failed\n");
208 		}
209 	}
210 #endif
211 
212 	/*
213 	 * We are ready to enter the next EL. Prepare entry into the image
214 	 * corresponding to the desired security state after the next ERET.
215 	 */
216 	bl31_prepare_next_image_entry();
217 
218 	/*
219 	 * Perform any platform specific runtime setup prior to cold boot exit
220 	 * from BL31
221 	 */
222 	bl31_plat_runtime_setup();
223 
224 #if ENABLE_RUNTIME_INSTRUMENTATION
225 	console_flush();
226 	PMF_CAPTURE_TIMESTAMP(bl_svc, BL31_EXIT, PMF_CACHE_MAINT);
227 #endif
228 
229 	console_flush();
230 	console_switch_state(CONSOLE_FLAG_RUNTIME);
231 }
232 
233 /*******************************************************************************
234  * Accessor functions to help runtime services decide which image should be
235  * executed after BL31. This is BL33 or the non-secure bootloader image by
236  * default but the Secure payload dispatcher could override this by requesting
237  * an entry into BL32 (Secure payload) first. If it does so then it should use
238  * the same API to program an entry into BL33 once BL32 initialisation is
239  * complete.
240  ******************************************************************************/
bl31_set_next_image_type(uint32_t security_state)241 void bl31_set_next_image_type(uint32_t security_state)
242 {
243 	assert(sec_state_is_valid(security_state));
244 	next_image_type = security_state;
245 }
246 
bl31_get_next_image_type(void)247 uint32_t bl31_get_next_image_type(void)
248 {
249 	return next_image_type;
250 }
251 
252 /*******************************************************************************
253  * This function programs EL3 registers and performs other setup to enable entry
254  * into the next image after BL31 at the next ERET.
255  ******************************************************************************/
bl31_prepare_next_image_entry(void)256 void __init bl31_prepare_next_image_entry(void)
257 {
258 	entry_point_info_t *next_image_info;
259 	uint32_t image_type;
260 
261 #if CTX_INCLUDE_AARCH32_REGS
262 	/*
263 	 * Ensure that the build flag to save AArch32 system registers in CPU
264 	 * context is not set for AArch64-only platforms.
265 	 */
266 	if (el_implemented(1) == EL_IMPL_A64ONLY) {
267 		ERROR("EL1 supports AArch64-only. Please set build flag "
268 				"CTX_INCLUDE_AARCH32_REGS = 0\n");
269 		panic();
270 	}
271 #endif
272 
273 	/* Determine which image to execute next */
274 	image_type = bl31_get_next_image_type();
275 
276 	/* Program EL3 registers to enable entry into the next EL */
277 	next_image_info = bl31_plat_get_next_image_ep_info(image_type);
278 	assert(next_image_info != NULL);
279 	assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr));
280 
281 	INFO("BL31: Preparing for EL3 exit to %s world\n",
282 		(image_type == SECURE) ? "secure" : "normal");
283 	print_entry_point_info(next_image_info);
284 	cm_init_my_context(next_image_info);
285 
286 	/*
287 	* If we are entering the Non-secure world, use
288 	* 'cm_prepare_el3_exit_ns' to exit.
289 	*/
290 	if (image_type == NON_SECURE) {
291 		cm_prepare_el3_exit_ns();
292 	} else {
293 		cm_prepare_el3_exit(image_type);
294 	}
295 }
296 
297 /*******************************************************************************
298  * This function initializes the pointer to BL32 init function. This is expected
299  * to be called by the SPD after it finishes all its initialization
300  ******************************************************************************/
bl31_register_bl32_init(int32_t (* func)(void))301 void bl31_register_bl32_init(int32_t (*func)(void))
302 {
303 	bl32_init = func;
304 }
305 
306 #if ENABLE_RME
307 /*******************************************************************************
308  * This function initializes the pointer to RMM init function. This is expected
309  * to be called by the RMMD after it finishes all its initialization
310  ******************************************************************************/
bl31_register_rmm_init(int32_t (* func)(void))311 void bl31_register_rmm_init(int32_t (*func)(void))
312 {
313 	rmm_init = func;
314 }
315 #endif
316