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/*
* Read a coreboot rmodule and execute it.
* The rmodule_header struct is from coreboot.
*
* Copyright (c) 2016 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <common.h>
#include <errno.h>
#include <asm/arch/pei_data.h>
#define RMODULE_MAGIC 0xf8fe
#define RMODULE_VERSION_1 1
/*
* All fields with '_offset' in the name are byte offsets into the flat blob.
* The linker and the linker script takes are of assigning the values.
*/
struct rmodule_header {
uint16_t magic;
uint8_t version;
uint8_t type;
/* The payload represents the program's loadable code and data */
uint32_t payload_begin_offset;
uint32_t payload_end_offset;
/* Begin and of relocation information about the program module */
uint32_t relocations_begin_offset;
uint32_t relocations_end_offset;
/*
* The starting address of the linked program. This address is vital
* for determining relocation offsets as the relocation info and other
* symbols (bss, entry point) need this value as a basis to calculate
* the offsets.
*/
uint32_t module_link_start_address;
/*
* The module_program_size is the size of memory used while running
* the program. The program is assumed to consume a contiguous amount
* of memory
*/
uint32_t module_program_size;
/* This is program's execution entry point */
uint32_t module_entry_point;
/*
* Optional parameter structure that can be used to pass data into
* the module
*/
uint32_t parameters_begin;
uint32_t parameters_end;
/* BSS section information so the loader can clear the bss */
uint32_t bss_begin;
uint32_t bss_end;
/* Add some room for growth */
uint32_t padding[4];
} __packed;
int cpu_run_reference_code(void)
{
struct pei_data _pei_data __aligned(8);
struct pei_data *pei_data = &_pei_data;
asmlinkage int (*func)(void *);
struct rmodule_header *hdr;
char *src, *dest;
int ret, dummy;
int size;
hdr = (struct rmodule_header *)CONFIG_X86_REFCODE_ADDR;
debug("Extracting code from rmodule at %p\n", hdr);
if (hdr->magic != RMODULE_MAGIC) {
debug("Invalid rmodule magic\n");
return -EINVAL;
}
if (hdr->module_link_start_address != 0) {
debug("Link start address must be 0\n");
return -EPERM;
}
if (hdr->module_entry_point != 0) {
debug("Entry point must be 0\n");
return -EPERM;
}
memset(pei_data, '\0', sizeof(struct pei_data));
broadwell_fill_pei_data(pei_data);
mainboard_fill_pei_data(pei_data);
pei_data->saved_data = (void *)&dummy;
src = (char *)hdr + hdr->payload_begin_offset;
dest = (char *)CONFIG_X86_REFCODE_RUN_ADDR;
size = hdr->payload_end_offset - hdr->payload_begin_offset;
debug("Copying refcode from %p to %p, size %x\n", src, dest, size);
memcpy(dest, src, size);
size = hdr->bss_end - hdr->bss_begin;
debug("Zeroing BSS at %p, size %x\n", dest + hdr->bss_begin, size);
memset(dest + hdr->bss_begin, '\0', size);
func = (asmlinkage int (*)(void *))dest;
debug("Running reference code at %p\n", func);
#ifdef DEBUG
print_buffer(CONFIG_X86_REFCODE_RUN_ADDR, (void *)func, 1, 0x40, 0);
#endif
ret = func(pei_data);
if (ret != 0) {
debug("Reference code returned %d\n", ret);
return -EL2HLT;
}
debug("Refereence code completed\n");
return 0;
}