1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Read a coreboot rmodule and execute it.
4 * The rmodule_header struct is from coreboot.
5 *
6 * Copyright (c) 2016 Google, Inc
7 */
8
9 #include <common.h>
10 #include <errno.h>
11 #include <init.h>
12 #include <log.h>
13 #include <asm/arch/pei_data.h>
14
15 #define RMODULE_MAGIC 0xf8fe
16 #define RMODULE_VERSION_1 1
17
18 /*
19 * All fields with '_offset' in the name are byte offsets into the flat blob.
20 * The linker and the linker script takes are of assigning the values.
21 */
22 struct rmodule_header {
23 uint16_t magic;
24 uint8_t version;
25 uint8_t type;
26 /* The payload represents the program's loadable code and data */
27 uint32_t payload_begin_offset;
28 uint32_t payload_end_offset;
29 /* Begin and of relocation information about the program module */
30 uint32_t relocations_begin_offset;
31 uint32_t relocations_end_offset;
32 /*
33 * The starting address of the linked program. This address is vital
34 * for determining relocation offsets as the relocation info and other
35 * symbols (bss, entry point) need this value as a basis to calculate
36 * the offsets.
37 */
38 uint32_t module_link_start_address;
39 /*
40 * The module_program_size is the size of memory used while running
41 * the program. The program is assumed to consume a contiguous amount
42 * of memory
43 */
44 uint32_t module_program_size;
45 /* This is program's execution entry point */
46 uint32_t module_entry_point;
47 /*
48 * Optional parameter structure that can be used to pass data into
49 * the module
50 */
51 uint32_t parameters_begin;
52 uint32_t parameters_end;
53 /* BSS section information so the loader can clear the bss */
54 uint32_t bss_begin;
55 uint32_t bss_end;
56 /* Add some room for growth */
57 uint32_t padding[4];
58 } __packed;
59
60 /**
61 * cpu_run_reference_code() - Run the platform reference code
62 *
63 * Some platforms require a binary blob to be executed once SDRAM is
64 * available. This is used to set up various platform features, such as the
65 * platform controller hub (PCH). This function should be implemented by the
66 * CPU-specific code.
67 *
68 * @return 0 on success, -ve on failure
69 */
cpu_run_reference_code(void)70 static int cpu_run_reference_code(void)
71 {
72 struct pei_data _pei_data __aligned(8);
73 struct pei_data *pei_data = &_pei_data;
74 asmlinkage int (*func)(void *);
75 struct rmodule_header *hdr;
76 char *src, *dest;
77 int ret, dummy;
78 int size;
79
80 hdr = (struct rmodule_header *)CONFIG_X86_REFCODE_ADDR;
81 debug("Extracting code from rmodule at %p\n", hdr);
82 if (hdr->magic != RMODULE_MAGIC) {
83 debug("Invalid rmodule magic\n");
84 return -EINVAL;
85 }
86 if (hdr->module_link_start_address != 0) {
87 debug("Link start address must be 0\n");
88 return -EPERM;
89 }
90 if (hdr->module_entry_point != 0) {
91 debug("Entry point must be 0\n");
92 return -EPERM;
93 }
94
95 memset(pei_data, '\0', sizeof(struct pei_data));
96 broadwell_fill_pei_data(pei_data);
97 mainboard_fill_pei_data(pei_data);
98 pei_data->saved_data = (void *)&dummy;
99
100 src = (char *)hdr + hdr->payload_begin_offset;
101 dest = (char *)CONFIG_X86_REFCODE_RUN_ADDR;
102
103 size = hdr->payload_end_offset - hdr->payload_begin_offset;
104 debug("Copying refcode from %p to %p, size %x\n", src, dest, size);
105 memcpy(dest, src, size);
106
107 size = hdr->bss_end - hdr->bss_begin;
108 debug("Zeroing BSS at %p, size %x\n", dest + hdr->bss_begin, size);
109 memset(dest + hdr->bss_begin, '\0', size);
110
111 func = (asmlinkage int (*)(void *))dest;
112 debug("Running reference code at %p\n", func);
113 #ifdef DEBUG
114 print_buffer(CONFIG_X86_REFCODE_RUN_ADDR, (void *)func, 1, 0x40, 0);
115 #endif
116 ret = func(pei_data);
117 if (ret != 0) {
118 debug("Reference code returned %d\n", ret);
119 return -EL2HLT;
120 }
121 debug("Refereence code completed\n");
122
123 return 0;
124 }
125
arch_early_init_r(void)126 int arch_early_init_r(void)
127 {
128 return cpu_run_reference_code();
129 }
130