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1 /*
2  * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 
9 #include <libfdt.h>
10 
11 #include <platform_def.h>
12 #include <arch_helpers.h>
13 #include <common/bl_common.h>
14 #include <lib/mmio.h>
15 #include <lib/xlat_tables/xlat_mmu_helpers.h>
16 #include <lib/xlat_tables/xlat_tables_defs.h>
17 #include <lib/xlat_tables/xlat_tables_v2.h>
18 #include <plat/common/platform.h>
19 #include <common/fdt_fixup.h>
20 #include <libfdt.h>
21 
22 #include <drivers/arm/gicv2.h>
23 
24 #include <rpi_shared.h>
25 
26 /*
27  * Fields at the beginning of armstub8.bin.
28  * While building the BL31 image, we put the stub magic into the binary.
29  * The GPU firmware detects this at boot time, clears that field as a
30  * confirmation and puts the kernel and DT address in the following words.
31  */
32 extern uint32_t stub_magic;
33 extern uint32_t dtb_ptr32;
34 extern uint32_t kernel_entry32;
35 
36 static const gicv2_driver_data_t rpi4_gic_data = {
37 	.gicd_base = RPI4_GIC_GICD_BASE,
38 	.gicc_base = RPI4_GIC_GICC_BASE,
39 };
40 
41 /*
42  * To be filled by the code below. At the moment BL32 is not supported.
43  * In the future these might be passed down from BL2.
44  */
45 static entry_point_info_t bl32_image_ep_info;
46 static entry_point_info_t bl33_image_ep_info;
47 
48 /*******************************************************************************
49  * Return a pointer to the 'entry_point_info' structure of the next image for
50  * the security state specified. BL33 corresponds to the non-secure image type
51  * while BL32 corresponds to the secure image type. A NULL pointer is returned
52  * if the image does not exist.
53  ******************************************************************************/
bl31_plat_get_next_image_ep_info(uint32_t type)54 entry_point_info_t *bl31_plat_get_next_image_ep_info(uint32_t type)
55 {
56 	entry_point_info_t *next_image_info;
57 
58 	assert(sec_state_is_valid(type) != 0);
59 
60 	next_image_info = (type == NON_SECURE)
61 			? &bl33_image_ep_info : &bl32_image_ep_info;
62 
63 	/* None of the images can have 0x0 as the entrypoint. */
64 	if (next_image_info->pc) {
65 		return next_image_info;
66 	} else {
67 		return NULL;
68 	}
69 }
70 
plat_get_ns_image_entrypoint(void)71 uintptr_t plat_get_ns_image_entrypoint(void)
72 {
73 #ifdef PRELOADED_BL33_BASE
74 	return PRELOADED_BL33_BASE;
75 #else
76 	/* Cleared by the GPU if kernel address is valid. */
77 	if (stub_magic == 0)
78 		return kernel_entry32;
79 
80 	WARN("Stub magic failure, using default kernel address 0x80000\n");
81 	return 0x80000;
82 #endif
83 }
84 
rpi4_get_dtb_address(void)85 static uintptr_t rpi4_get_dtb_address(void)
86 {
87 #ifdef RPI3_PRELOADED_DTB_BASE
88 	return RPI3_PRELOADED_DTB_BASE;
89 #else
90 	/* Cleared by the GPU if DTB address is valid. */
91 	if (stub_magic == 0)
92 		return dtb_ptr32;
93 
94 	WARN("Stub magic failure, DTB address unknown\n");
95 	return 0;
96 #endif
97 }
98 
ldelay(register_t delay)99 static void ldelay(register_t delay)
100 {
101 	__asm__ volatile (
102 		"1:\tcbz %0, 2f\n\t"
103 		"sub %0, %0, #1\n\t"
104 		"b 1b\n"
105 		"2:"
106 		: "=&r" (delay) : "0" (delay)
107 	);
108 }
109 
110 /*******************************************************************************
111  * Perform any BL31 early platform setup. Here is an opportunity to copy
112  * parameters passed by the calling EL (S-EL1 in BL2 & EL3 in BL1) before
113  * they are lost (potentially). This needs to be done before the MMU is
114  * initialized so that the memory layout can be used while creating page
115  * tables. BL2 has flushed this information to memory, so we are guaranteed
116  * to pick up good data.
117  ******************************************************************************/
bl31_early_platform_setup2(u_register_t arg0,u_register_t arg1,u_register_t arg2,u_register_t arg3)118 void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
119 				u_register_t arg2, u_register_t arg3)
120 
121 {
122 	/*
123 	 * LOCAL_CONTROL:
124 	 * Bit 9 clear: Increment by 1 (vs. 2).
125 	 * Bit 8 clear: Timer source is 19.2MHz crystal (vs. APB).
126 	 */
127 	mmio_write_32(RPI4_LOCAL_CONTROL_BASE_ADDRESS, 0);
128 
129 	/* LOCAL_PRESCALER; divide-by (0x80000000 / register_val) == 1 */
130 	mmio_write_32(RPI4_LOCAL_CONTROL_PRESCALER, 0x80000000);
131 
132 	/* Early GPU firmware revisions need a little break here. */
133 	ldelay(100000);
134 
135 	/*
136 	 * Initialize the console to provide early debug support.
137 	 * We rely on the GPU firmware to have initialised the UART correctly,
138 	 * as the baud base clock rate differs across GPU firmware revisions.
139 	 * Providing a base clock of 0 lets the 16550 UART init routine skip
140 	 * the initial enablement and baud rate setup.
141 	 */
142 	rpi3_console_init(0);
143 
144 	bl33_image_ep_info.pc = plat_get_ns_image_entrypoint();
145 	bl33_image_ep_info.spsr = rpi3_get_spsr_for_bl33_entry();
146 	SET_SECURITY_STATE(bl33_image_ep_info.h.attr, NON_SECURE);
147 
148 #if RPI3_DIRECT_LINUX_BOOT
149 # if RPI3_BL33_IN_AARCH32
150 	/*
151 	 * According to the file ``Documentation/arm/Booting`` of the Linux
152 	 * kernel tree, Linux expects:
153 	 * r0 = 0
154 	 * r1 = machine type number, optional in DT-only platforms (~0 if so)
155 	 * r2 = Physical address of the device tree blob
156 	 */
157 	VERBOSE("rpi4: Preparing to boot 32-bit Linux kernel\n");
158 	bl33_image_ep_info.args.arg0 = 0U;
159 	bl33_image_ep_info.args.arg1 = ~0U;
160 	bl33_image_ep_info.args.arg2 = rpi4_get_dtb_address();
161 # else
162 	/*
163 	 * According to the file ``Documentation/arm64/booting.txt`` of the
164 	 * Linux kernel tree, Linux expects the physical address of the device
165 	 * tree blob (DTB) in x0, while x1-x3 are reserved for future use and
166 	 * must be 0.
167 	 */
168 	VERBOSE("rpi4: Preparing to boot 64-bit Linux kernel\n");
169 	bl33_image_ep_info.args.arg0 = rpi4_get_dtb_address();
170 	bl33_image_ep_info.args.arg1 = 0ULL;
171 	bl33_image_ep_info.args.arg2 = 0ULL;
172 	bl33_image_ep_info.args.arg3 = 0ULL;
173 # endif /* RPI3_BL33_IN_AARCH32 */
174 #endif /* RPI3_DIRECT_LINUX_BOOT */
175 }
176 
bl31_plat_arch_setup(void)177 void bl31_plat_arch_setup(void)
178 {
179 	/*
180 	 * Is the dtb_ptr32 pointer valid? If yes, map the DTB region.
181 	 * We map the 2MB region the DTB start address lives in, plus
182 	 * the next 2MB, to have enough room for expansion.
183 	 */
184 	if (stub_magic == 0) {
185 		unsigned long long dtb_region = dtb_ptr32;
186 
187 		dtb_region &= ~0x1fffff;	/* Align to 2 MB. */
188 		mmap_add_region(dtb_region, dtb_region, 4U << 20,
189 				MT_MEMORY | MT_RW | MT_NS);
190 	}
191 	/*
192 	 * Add the first page of memory, which holds the stub magic,
193 	 * the kernel and the DT address.
194 	 * This also holds the secondary CPU's entrypoints and mailboxes.
195 	 */
196 	mmap_add_region(0, 0, 4096, MT_NON_CACHEABLE | MT_RW | MT_SECURE);
197 
198 	rpi3_setup_page_tables(BL31_BASE, BL31_END - BL31_BASE,
199 			       BL_CODE_BASE, BL_CODE_END,
200 			       BL_RO_DATA_BASE, BL_RO_DATA_END
201 #if USE_COHERENT_MEM
202 			       , BL_COHERENT_RAM_BASE, BL_COHERENT_RAM_END
203 #endif
204 			      );
205 
206 	enable_mmu_el3(0);
207 }
208 
dtb_size(const void * dtb)209 static uint32_t dtb_size(const void *dtb)
210 {
211 	const uint32_t *dtb_header = dtb;
212 
213 	return fdt32_to_cpu(dtb_header[1]);
214 }
215 
rpi4_prepare_dtb(void)216 static void rpi4_prepare_dtb(void)
217 {
218 	void *dtb = (void *)rpi4_get_dtb_address();
219 	uint32_t gic_int_prop[3];
220 	int ret, offs;
221 
222 	/* Return if no device tree is detected */
223 	if (fdt_check_header(dtb) != 0)
224 		return;
225 
226 	ret = fdt_open_into(dtb, dtb, 0x100000);
227 	if (ret < 0) {
228 		ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret);
229 		return;
230 	}
231 
232 	if (dt_add_psci_node(dtb)) {
233 		ERROR("Failed to add PSCI Device Tree node\n");
234 		return;
235 	}
236 
237 	if (dt_add_psci_cpu_enable_methods(dtb)) {
238 		ERROR("Failed to add PSCI cpu enable methods in Device Tree\n");
239 		return;
240 	}
241 
242 	/* Reserve memory used by Trusted Firmware. */
243 	if (fdt_add_reserved_memory(dtb, "atf@0", 0, 0x80000))
244 		WARN("Failed to add reserved memory nodes to DT.\n");
245 
246 	offs = fdt_node_offset_by_compatible(dtb, 0, "arm,gic-400");
247 	gic_int_prop[0] = cpu_to_fdt32(1);		// PPI
248 	gic_int_prop[1] = cpu_to_fdt32(9);		// PPI #9
249 	gic_int_prop[2] = cpu_to_fdt32(0x0f04);		// all cores, level high
250 	fdt_setprop(dtb, offs, "interrupts", gic_int_prop, 12);
251 
252 	offs = fdt_path_offset(dtb, "/chosen");
253 	fdt_setprop_string(dtb, offs, "stdout-path", "serial0");
254 
255 	ret = fdt_pack(dtb);
256 	if (ret < 0)
257 		ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret);
258 
259 	clean_dcache_range((uintptr_t)dtb, dtb_size(dtb));
260 	INFO("Changed device tree to advertise PSCI.\n");
261 }
262 
bl31_platform_setup(void)263 void bl31_platform_setup(void)
264 {
265 	rpi4_prepare_dtb();
266 
267 	/* Configure the interrupt controller */
268 	gicv2_driver_init(&rpi4_gic_data);
269 	gicv2_distif_init();
270 	gicv2_pcpu_distif_init();
271 	gicv2_cpuif_enable();
272 }
273