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