xref: /openbmc/u-boot/arch/arm/mach-exynos/sec_boot.S (revision dd1033e4)
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * Copyright (C) 2013 Samsung Electronics
4 * Akshay Saraswat <akshay.s@samsung.com>
5 */
6
7#include <config.h>
8#include <asm/arch/cpu.h>
9
10	.globl relocate_wait_code
11relocate_wait_code:
12	adr     r0, code_base		@ r0: source address (start)
13	adr     r1, code_end		@ r1: source address (end)
14	ldr     r2, =0x02073000		@ r2: target address
151:
16	ldmia   r0!, {r3-r6}
17	stmia   r2!, {r3-r6}
18	cmp     r0, r1
19	blt     1b
20	b	code_end
21	.ltorg
22/*
23 * Secondary core waits here until Primary wake it up.
24 * Below code is copied to CONFIG_EXYNOS_RELOCATE_CODE_BASE.
25 * This is a workaround code which is supposed to act as a
26 * substitute/supplement to the iROM code.
27 *
28 * This workaround code is relocated to the address 0x02073000
29 * because that comes out to be the last 4KB of the iRAM
30 * (Base Address - 0x02020000, Limit Address - 0x020740000).
31 *
32 * U-Boot and kernel are aware of this code and flags by the simple
33 * fact that we are implementing a workaround in the last 4KB
34 * of the iRAM and we have already defined these flag and address
35 * values in both kernel and U-Boot for our use.
36 */
37code_base:
38	b	 1f
39/*
40 * These addresses are being used as flags in u-boot and kernel.
41 *
42 * Jump address for resume and flag to check for resume/reset:
43 * Resume address - 0x2073008
44 * Resume flag - 0x207300C
45 *
46 * Jump address for cluster switching:
47 * Switch address - 0x2073018
48 *
49 * Jump address for core hotplug:
50 * Hotplug address - 0x207301C
51 *
52 * Jump address for C2 state (Reserved for future not being used right now):
53 * C2 address - 0x2073024
54 *
55 * Managed per core status for the active cluster:
56 * CPU0 state - 0x2073028
57 * CPU1 state - 0x207302C
58 * CPU2 state - 0x2073030
59 * CPU3 state - 0x2073034
60 *
61 * Managed per core GIC status for the active cluster:
62 * CPU0 gic state - 0x2073038
63 * CPU1 gic state - 0x207303C
64 * CPU2 gic state - 0x2073040
65 * CPU3 gic state - 0x2073044
66 *
67 * Logic of the code:
68 * Step-1: Read current CPU status.
69 * Step-2: If it's a resume then continue, else jump to step 4.
70 * Step-3: Clear inform1 PMU register and jump to inform0 value.
71 * Step-4: If it's a switch, C2 or reset, get the hotplug address.
72 * Step-5: If address is not available, enter WFE.
73 * Step-6: If address is available, jump to that address.
74 */
75	nop			     @ for backward compatibility
76	.word   0x0		     @ REG0: RESUME_ADDR
77	.word   0x0		     @ REG1: RESUME_FLAG
78	.word   0x0		     @ REG2
79	.word   0x0		     @ REG3
80_switch_addr:
81	.word   0x0		     @ REG4: SWITCH_ADDR
82_hotplug_addr:
83	.word   0x0		     @ REG5: CPU1_BOOT_REG
84	.word   0x0		     @ REG6
85_c2_addr:
86	.word   0x0		     @ REG7: REG_C2_ADDR
87_cpu_state:
88	.word   0x1		     @ CPU0_STATE : RESET
89	.word   0x2		     @ CPU1_STATE : SECONDARY RESET
90	.word   0x2		     @ CPU2_STATE : SECONDARY RESET
91	.word   0x2		     @ CPU3_STATE : SECONDARY RESET
92_gic_state:
93	.word   0x0		     @ CPU0 - GICD_IGROUPR0
94	.word   0x0		     @ CPU1 - GICD_IGROUPR0
95	.word   0x0		     @ CPU2 - GICD_IGROUPR0
96	.word   0x0		     @ CPU3 - GICD_IGROUPR0
971:
98	adr     r0, _cpu_state
99	mrc     p15, 0, r7, c0, c0, 5   @ read MPIDR
100	and     r7, r7, #0xf	    @ r7 = cpu id
101/* Read the current cpu state */
102	ldr     r10, [r0, r7, lsl #2]
103svc_entry:
104	tst     r10, #(1 << 4)
105	adrne   r0, _switch_addr
106	bne     wait_for_addr
107/* Clear INFORM1 */
108	ldr     r0, =(0x10040000 + 0x804)
109	ldr     r1, [r0]
110	cmp     r1, #0x0
111	movne   r1, #0x0
112	strne   r1, [r0]
113/* Get INFORM0 */
114	ldrne   r1, =(0x10040000 + 0x800)
115	ldrne   pc, [r1]
116	tst     r10, #(1 << 0)
117	ldrne   pc, =0x23e00000
118	adr     r0, _hotplug_addr
119wait_for_addr:
120	ldr     r1, [r0]
121	cmp     r1, #0x0
122	bxne    r1
123	wfe
124	b	 wait_for_addr
125	.ltorg
126code_end:
127	mov	pc, lr
128