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