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 <display_options.h> 11#include <errno.h> 12#include <init.h> 13#include <log.h> 14#include <asm/arch/pei_data.h> 15 16#define RMODULE_MAGIC 0xf8fe 17#define RMODULE_VERSION_1 1 18 19/* 20 * All fields with '_offset' in the name are byte offsets into the flat blob. 21 * The linker and the linker script takes are of assigning the values. 22 */ 23struct rmodule_header { 24 uint16_t magic; 25 uint8_t version; 26 uint8_t type; 27 /* The payload represents the program's loadable code and data */ 28 uint32_t payload_begin_offset; 29 uint32_t payload_end_offset; 30 /* Begin and of relocation information about the program module */ 31 uint32_t relocations_begin_offset; 32 uint32_t relocations_end_offset; 33 /* 34 * The starting address of the linked program. This address is vital 35 * for determining relocation offsets as the relocation info and other 36 * symbols (bss, entry point) need this value as a basis to calculate 37 * the offsets. 38 */ 39 uint32_t module_link_start_address; 40 /* 41 * The module_program_size is the size of memory used while running 42 * the program. The program is assumed to consume a contiguous amount 43 * of memory 44 */ 45 uint32_t module_program_size; 46 /* This is program's execution entry point */ 47 uint32_t module_entry_point; 48 /* 49 * Optional parameter structure that can be used to pass data into 50 * the module 51 */ 52 uint32_t parameters_begin; 53 uint32_t parameters_end; 54 /* BSS section information so the loader can clear the bss */ 55 uint32_t bss_begin; 56 uint32_t bss_end; 57 /* Add some room for growth */ 58 uint32_t padding[4]; 59} __packed; 60 61/** 62 * cpu_run_reference_code() - Run the platform reference code 63 * 64 * Some platforms require a binary blob to be executed once SDRAM is 65 * available. This is used to set up various platform features, such as the 66 * platform controller hub (PCH). This function should be implemented by the 67 * CPU-specific code. 68 * 69 * Return: 0 on success, -ve on failure 70 */ 71static int cpu_run_reference_code(void) 72{ 73 struct pei_data _pei_data __aligned(8); 74 struct pei_data *pei_data = &_pei_data; 75 asmlinkage int (*func)(void *); 76 struct rmodule_header *hdr; 77 char *src, *dest; 78 int ret, dummy; 79 int size; 80 81 hdr = (struct rmodule_header *)CFG_X86_REFCODE_ADDR; 82 debug("Extracting code from rmodule at %p\n", hdr); 83 if (hdr->magic != RMODULE_MAGIC) { 84 debug("Invalid rmodule magic\n"); 85 return -EINVAL; 86 } 87 if (hdr->module_link_start_address != 0) { 88 debug("Link start address must be 0\n"); 89 return -EPERM; 90 } 91 if (hdr->module_entry_point != 0) { 92 debug("Entry point must be 0\n"); 93 return -EPERM; 94 } 95 96 memset(pei_data, '\0', sizeof(struct pei_data)); 97 broadwell_fill_pei_data(pei_data); 98 mainboard_fill_pei_data(pei_data); 99 pei_data->saved_data = (void *)&dummy; 100 101 src = (char *)hdr + hdr->payload_begin_offset; 102 dest = (char *)CFG_X86_REFCODE_RUN_ADDR; 103 104 size = hdr->payload_end_offset - hdr->payload_begin_offset; 105 debug("Copying refcode from %p to %p, size %x\n", src, dest, size); 106 memcpy(dest, src, size); 107 108 size = hdr->bss_end - hdr->bss_begin; 109 debug("Zeroing BSS at %p, size %x\n", dest + hdr->bss_begin, size); 110 memset(dest + hdr->bss_begin, '\0', size); 111 112 func = (asmlinkage int (*)(void *))dest; 113 debug("Running reference code at %p\n", func); 114#ifdef DEBUG 115 print_buffer(CFG_X86_REFCODE_RUN_ADDR, (void *)func, 1, 0x40, 0); 116#endif 117 ret = func(pei_data); 118 if (ret != 0) { 119 debug("Reference code returned %d\n", ret); 120 return -EL2HLT; 121 } 122 debug("Refereence code completed\n"); 123 124 return 0; 125} 126 127int arch_early_init_r(void) 128{ 129 return cpu_run_reference_code(); 130} 131