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