boot.S revision 13509 
1/*
2 * Copyright (c) 2012 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 */
38
39        .text
40
41        .globl	_start
42_start:
43        /*
44         * EL3 initialisation
45         */
46        mrs	x0, CurrentEL
47        cmp	x0, #0xc			// EL3?
48        b.ne	start_ns			// skip EL3 initialisation
49
50        mov	x0, #0x30			// RES1
51        orr	x0, x0, #(1 << 0)		// Non-secure EL1
52        orr	x0, x0, #(1 << 8)		// HVC enable
53        orr	x0, x0, #(1 << 10)		// 64-bit EL2
54        msr	scr_el3, x0
55
56        msr	cptr_el3, xzr			// Disable copro. traps to EL3
57
58        ldr	x0, =CNTFRQ
59        msr	cntfrq_el0, x0
60
61        /*
62         * Check for the primary CPU to avoid a race on the distributor
63         * registers.
64         */
65        mrs	x0, mpidr_el1
66        // ARM MPIDR_EL1 bytes: Aff3 (AArch64), Stuff, Aff2, Aff1, Aff0
67        // Test the the MPIDR_EL1 register against 0xff00ffffff to
68        // extract the primary CPU.
69        ldr x1, =0xff00ffffff
70#ifdef GICV3
71        and	x2, x0, #0xff // use Aff0 as cpuid for now...
72        tst	x0, x1 // check for cpuid==zero
73        b.ne	1f // secondary CPU
74
75        ldr	x1, =GIC_DIST_BASE // GICD_CTLR
76        mov	w0, #7 // EnableGrp0 | EnableGrp1NS | EnableGrp1S
77        str	w0, [x1]
78
79
801:      ldr	x1, =GIC_REDIST_BASE + 0x10000 + 0x80 // GICR_IGROUPR0
81        // 128K for each redistributor, 256K strided...
82        mov	x3, #1 << 18 // GICv4
83        mul	x3, x3, x2
84        add	x1, x1, x3
85        mov	w0, #~0 // Grp1 interrupts
86        str	w0, [x1], #4
87        b.ne	2f // Only local interrupts for secondary CPUs
88        ldr	x1, =GIC_DIST_BASE + 0x84 // GICD_IGROUPR
89        str	w0, [x1], #4
90        str	w0, [x1], #4
91        str	w0, [x1], #4
92
93
942:      mov	x0, #1
95        msr	S3_0_c12_c12_6, x0 // ICC_IGRPEN0_EL1 Enable
96        msr	S3_0_C12_C12_7, x0 // ICC_IGRPEN1_EL1 Enable
97#else
98        tst x0, x1                    // check for cpuid==zero
99        b.ne	1f				      // secondary CPU
100
101        ldr	x1, =GIC_DIST_BASE		// GICD_CTLR
102        mov	w0, #3				// EnableGrp0 | EnableGrp1
103        str	w0, [x1]
104
1051:	ldr	x1, =GIC_DIST_BASE + 0x80	// GICD_IGROUPR
106        mov	w0, #~0				// Grp1 interrupts
107        str	w0, [x1], #4
108        b.ne	2f				// Only local interrupts for secondary CPUs
109        str	w0, [x1], #4
110        str	w0, [x1], #4
111
1122:	ldr	x1, =GIC_CPU_BASE		// GICC_CTLR
113        ldr	w0, [x1]
114        mov	w0, #3				// EnableGrp0 | EnableGrp1
115        str	w0, [x1]
116
117        mov	w0, #1 << 7			// allow NS access to GICC_PMR
118        str	w0, [x1, #4]			// GICC_PMR
119#endif
120
121        msr	sctlr_el2, xzr
122
123        /*
124         * Prepare the switch to the EL2_SP1 mode from EL3
125         */
126        ldr	x0, =start_ns			// Return after mode switch
127        mov	x1, #0x3c9			// EL2_SP1 | D | A | I | F
128        msr	elr_el3, x0
129        msr	spsr_el3, x1
130        eret
131
132start_ns:
133        /*
134         * Kernel parameters
135         */
136        mov	x0, xzr
137        mov	x1, xzr
138        mov	x2, xzr
139        mov	x3, xzr
140
141        mrs	x4, mpidr_el1
142        // ARM MPIDR_EL1 bytes: Aff3 (AArch64), Stuff, Aff2, Aff1, Aff0
143        // Test the the MPIDR_EL1 register against 0xff00ffffff to
144        // extract the primary CPU.
145        ldr x1, =0xff00ffffff
146        tst x4, x1                    // check for cpuid==zero
147        mov x1, xzr                   // load previous 'xzr' value back to x1
148        b.eq	2f				      // secondary CPU
149
150        /*
151         * Secondary CPUs
152         */
1531:	wfe
154        ldr	x4, =PHYS_OFFSET + 0xfff8
155        ldr     x4, [x4]
156        cbz	x4, 1b
157        br	x4				// branch to the given address
158
1592:
160        /*
161         * UART initialisation (38400 8N1)
162         */
163        ldr	x4, =UART_BASE			// UART base
164        mov	w5, #0x10			// ibrd
165        str	w5, [x4, #0x24]
166        mov	w5, #0xc300
167        orr	w5, w5, #0x0001			// cr
168        str	w5, [x4, #0x30]
169
170        /*
171         * CLCD output site MB
172         */
173        ldr	x4, =SYSREGS_BASE
174        ldr	w5, =(1 << 31) | (1 << 30) | (7 << 20) | (0 << 16)	// START|WRITE|MUXFPGA|SITE_MB
175        str	wzr, [x4, #0xa0]		// V2M_SYS_CFGDATA
176        str	w5, [x4, #0xa4]			// V2M_SYS_CFGCTRL
177
178        // set up the arch timer frequency
179        //ldr	x0, =CNTFRQ
180        //msr	cntfrq_el0, x0
181
182        /*
183         * Primary CPU
184         */
185        ldr	x0, =PHYS_OFFSET + 0x8000000	 // device tree blob
186        ldr     x6, =PHYS_OFFSET + 0x80000       // kernel start address
187        br	x6
188
189        .ltorg
190
191        .org	0x200
192