LXR uboot/arch/x86/cpu/broadwell/refcode.c

   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 */
  20struct 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 */
  68static 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
 124int arch_early_init_r(void)
 125{
 126        return cpu_run_reference_code();
 127}
 128