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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2016 Freescale Semiconductor, Inc.
4  */
5 
6 #include <common.h>
7 #include <asm/io.h>
8 #include <asm/mach-imx/sys_proto.h>
9 #include <command.h>
10 #include <imx_sip.h>
11 #include <linux/compiler.h>
12 
arch_auxiliary_core_up(u32 core_id,ulong boot_private_data)13 int arch_auxiliary_core_up(u32 core_id, ulong boot_private_data)
14 {
15 	ulong stack, pc;
16 
17 	if (!boot_private_data)
18 		return -EINVAL;
19 
20 	stack = *(u32 *)boot_private_data;
21 	pc = *(u32 *)(boot_private_data + 4);
22 
23 	/* Set the stack and pc to M4 bootROM */
24 	writel(stack, M4_BOOTROM_BASE_ADDR);
25 	writel(pc, M4_BOOTROM_BASE_ADDR + 4);
26 
27 	/* Enable M4 */
28 #ifdef CONFIG_IMX8M
29 	call_imx_sip(IMX_SIP_SRC, IMX_SIP_SRC_M4_START, 0, 0, 0);
30 #else
31 	clrsetbits_le32(SRC_BASE_ADDR + SRC_M4_REG_OFFSET,
32 			SRC_M4C_NON_SCLR_RST_MASK, SRC_M4_ENABLE_MASK);
33 #endif
34 
35 	return 0;
36 }
37 
arch_auxiliary_core_check_up(u32 core_id)38 int arch_auxiliary_core_check_up(u32 core_id)
39 {
40 #ifdef CONFIG_IMX8M
41 	return call_imx_sip(IMX_SIP_SRC, IMX_SIP_SRC_M4_STARTED, 0, 0, 0);
42 #else
43 	unsigned int val;
44 
45 	val = readl(SRC_BASE_ADDR + SRC_M4_REG_OFFSET);
46 
47 	if (val & SRC_M4C_NON_SCLR_RST_MASK)
48 		return 0;  /* assert in reset */
49 
50 	return 1;
51 #endif
52 }
53 
54 /*
55  * To i.MX6SX and i.MX7D, the image supported by bootaux needs
56  * the reset vector at the head for the image, with SP and PC
57  * as the first two words.
58  *
59  * Per the cortex-M reference manual, the reset vector of M4 needs
60  * to exist at 0x0 (TCMUL). The PC and SP are the first two addresses
61  * of that vector.  So to boot M4, the A core must build the M4's reset
62  * vector with getting the PC and SP from image and filling them to
63  * TCMUL. When M4 is kicked, it will load the PC and SP by itself.
64  * The TCMUL is mapped to (M4_BOOTROM_BASE_ADDR) at A core side for
65  * accessing the M4 TCMUL.
66  */
do_bootaux(cmd_tbl_t * cmdtp,int flag,int argc,char * const argv[])67 static int do_bootaux(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
68 {
69 	ulong addr;
70 	int ret, up;
71 
72 	if (argc < 2)
73 		return CMD_RET_USAGE;
74 
75 	up = arch_auxiliary_core_check_up(0);
76 	if (up) {
77 		printf("## Auxiliary core is already up\n");
78 		return CMD_RET_SUCCESS;
79 	}
80 
81 	addr = simple_strtoul(argv[1], NULL, 16);
82 
83 	printf("## Starting auxiliary core at 0x%08lX ...\n", addr);
84 
85 	ret = arch_auxiliary_core_up(0, addr);
86 	if (ret)
87 		return CMD_RET_FAILURE;
88 
89 	return CMD_RET_SUCCESS;
90 }
91 
92 U_BOOT_CMD(
93 	bootaux, CONFIG_SYS_MAXARGS, 1,	do_bootaux,
94 	"Start auxiliary core",
95 	""
96 );
97