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