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

   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 */
  21struct 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
  59int cpu_run_reference_code(void)
  60{
  61        struct pei_data _pei_data __aligned(8);
  62        struct pei_data *pei_data = &_pei_data;
  63        asmlinkage int (*func)(void *);
  64        struct rmodule_header *hdr;
  65        char *src, *dest;
  66        int ret, dummy;
  67        int size;
  68
  69        hdr = (struct rmodule_header *)CONFIG_X86_REFCODE_ADDR;
  70        debug("Extracting code from rmodule at %p\n", hdr);
  71        if (hdr->magic != RMODULE_MAGIC) {
  72                debug("Invalid rmodule magic\n");
  73                return -EINVAL;
  74        }
  75        if (hdr->module_link_start_address != 0) {
  76                debug("Link start address must be 0\n");
  77                return -EPERM;
  78        }
  79        if (hdr->module_entry_point != 0) {
  80                debug("Entry point must be 0\n");
  81                return -EPERM;
  82        }
  83
  84        memset(pei_data, '\0', sizeof(struct pei_data));
  85        broadwell_fill_pei_data(pei_data);
  86        mainboard_fill_pei_data(pei_data);
  87        pei_data->saved_data = (void *)&dummy;
  88
  89        src = (char *)hdr + hdr->payload_begin_offset;
  90        dest = (char *)CONFIG_X86_REFCODE_RUN_ADDR;
  91
  92        size = hdr->payload_end_offset - hdr->payload_begin_offset;
  93        debug("Copying refcode from %p to %p, size %x\n", src, dest, size);
  94        memcpy(dest, src, size);
  95
  96        size = hdr->bss_end - hdr->bss_begin;
  97        debug("Zeroing BSS at %p, size %x\n", dest + hdr->bss_begin, size);
  98        memset(dest + hdr->bss_begin, '\0', size);
  99
 100        func = (asmlinkage int (*)(void *))dest;
 101        debug("Running reference code at %p\n", func);
 102#ifdef DEBUG
 103        print_buffer(CONFIG_X86_REFCODE_RUN_ADDR, (void *)func, 1, 0x40, 0);
 104#endif
 105        ret = func(pei_data);
 106        if (ret != 0) {
 107                debug("Reference code returned %d\n", ret);
 108                return -EL2HLT;
 109        }
 110        debug("Refereence code completed\n");
 111
 112        return 0;
 113}
 114