1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3  * Copyright (c) 2019 Western Digital Corporation or its affiliates.
4  *
5  * Based on include/sbi/{fw_dynamic.h,sbi_scratch.h} from the OpenSBI project.
6  */
7 #ifndef OPENSBI_H
8 #define OPENSBI_H
9 
10 /** Expected value of info magic ('OSBI' ascii string in hex) */
11 #define FW_DYNAMIC_INFO_MAGIC_VALUE		0x4942534f
12 
13 /** Maximum supported info version */
14 #define FW_DYNAMIC_INFO_VERSION			0x2
15 
16 /** Possible next mode values */
17 #define FW_DYNAMIC_INFO_NEXT_MODE_U		0x0
18 #define FW_DYNAMIC_INFO_NEXT_MODE_S		0x1
19 #define FW_DYNAMIC_INFO_NEXT_MODE_M		0x3
20 
21 enum sbi_scratch_options {
22 	/** Disable prints during boot */
23 	SBI_SCRATCH_NO_BOOT_PRINTS = (1 << 0),
24 };
25 
26 /** Representation dynamic info passed by previous booting stage */
27 struct fw_dynamic_info {
28 	/** Info magic */
29 	unsigned long magic;
30 	/** Info version */
31 	unsigned long version;
32 	/** Next booting stage address */
33 	unsigned long next_addr;
34 	/** Next booting stage mode */
35 	unsigned long next_mode;
36 	/** Options for OpenSBI library */
37 	unsigned long options;
38 	/**
39 	 * Preferred boot HART id
40 	 *
41 	 * It is possible that the previous booting stage uses same link
42 	 * address as the FW_DYNAMIC firmware. In this case, the relocation
43 	 * lottery mechanism can potentially overwrite the previous booting
44 	 * stage while other HARTs are still running in the previous booting
45 	 * stage leading to boot-time crash. To avoid this boot-time crash,
46 	 * the previous booting stage can specify last HART that will jump
47 	 * to the FW_DYNAMIC firmware as the preferred boot HART.
48 	 *
49 	 * To avoid specifying a preferred boot HART, the previous booting
50 	 * stage can set it to -1UL which will force the FW_DYNAMIC firmware
51 	 * to use the relocation lottery mechanism.
52 	 */
53 	unsigned long boot_hart;
54 } __packed;
55 
56 #endif
57