blob: b56ec322be759d1924ef0f9b3c924afc8947f491 [file] [log] [blame]
* This file is part of the coreboot project.
* Copyright (C) 2012 ChromeOS Authors
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <console/console.h>
#include <rmodule.h>
/* Change this define to get more verbose debugging for module loading. */
* On X86, the only relocations currently allowed are R_386_RELATIVE which
* have '0' for the symbol info in the relocation metadata (in r_info).
* The reason is that the module is fully linked and just has the relocations'
* locations.
typedef struct {
u32 r_offset;
u32 r_info;
} Elf32_Rel;
#define R_386_RELATIVE 8
#define RELOCTION_ENTRY_SIZE sizeof(Elf32_Rel)
static inline int rmodule_reloc_offset(const void *reloc)
const Elf32_Rel *rel = reloc;
return rel->r_offset;
static inline int rmodule_reloc_valid(const void *reloc)
const Elf32_Rel *rel = reloc;
return (rel->r_info == R_386_RELATIVE);
static inline void *remodule_next_reloc(const void *reloc)
const Elf32_Rel *rel = reloc;
return (void *)rel;
#error Arch needs to add relocation information support for RMODULE
static inline int rmodule_is_loaded(const struct rmodule *module)
return module->location != NULL;
/* Calculate a loaded program address based on the blob address. */
static inline void *rmodule_load_addr(const struct rmodule *module,
u32 blob_addr)
char *loc = module->location;
return &loc[blob_addr - module->header->module_link_start_address];
/* Initialize a rmodule structure based on raw data. */
int rmodule_parse(void *ptr, struct rmodule *module)
char *base;
struct rmodule_header *rhdr;
base = ptr;
rhdr = ptr;
if (rhdr == NULL)
return -1;
/* Sanity check the raw data. */
if (rhdr->magic != RMODULE_MAGIC)
return -1;
if (rhdr->version != RMODULE_VERSION_1)
return -1;
/* Indicate the module hasn't been loaded yet. */
module->location = NULL;
/* The rmodule only needs a reference to the reloc_header. */
module->header = rhdr;
/* The payload lives after the header. */
module->payload = &base[rhdr->payload_begin_offset];
module->payload_size = rhdr->payload_end_offset -
module->relocations = &base[rhdr->relocations_begin_offset];
return 0;
int rmodule_memory_size(const struct rmodule *module)
return module->header->module_program_size;
void *rmodule_parameters(const struct rmodule *module)
if (!rmodule_is_loaded(module))
return NULL;
/* Indicate if there are no parameters. */
if (module->header->parameters_begin == module->header->parameters_end)
return NULL;
return rmodule_load_addr(module, module->header->parameters_begin);
int rmodule_entry_offset(const struct rmodule *module)
return module->header->module_entry_point -
void *rmodule_entry(const struct rmodule *module)
if (!rmodule_is_loaded(module))
return NULL;
return rmodule_load_addr(module, module->header->module_entry_point);
static void rmodule_clear_bss(struct rmodule *module)
char *begin;
int size;
begin = rmodule_load_addr(module, module->header->bss_begin);
size = module->header->bss_end - module->header->bss_begin;
memset(begin, 0, size);
static inline int rmodule_number_relocations(const struct rmodule *module)
int r;
r = module->header->relocations_end_offset;
r -= module->header->relocations_begin_offset;
return r;
static void rmodule_copy_payload(const struct rmodule *module)
printk(BIOS_DEBUG, "Loading module at %p with entry %p. "
"filesize: 0x%x memsize: 0x%x\n",
module->location, rmodule_entry(module),
module->payload_size, rmodule_memory_size(module));
/* No need to copy the payload if the load location and the
* payload location are the same. */
if (module->location == module->payload)
memcpy(module->location, module->payload, module->payload_size);
static inline u32 *rmodule_adjustment_location(const struct rmodule *module,
const void *reloc)
int reloc_offset;
/* Don't relocate header field entries -- only program relocations. */
reloc_offset = rmodule_reloc_offset(reloc);
if (reloc_offset < module->header->module_link_start_address)
return NULL;
return rmodule_load_addr(module, reloc_offset);
static int rmodule_relocate(const struct rmodule *module)
int num_relocations;
const void *reloc;
u32 adjustment;
/* Each relocation needs to be adjusted relative to the beginning of
* the loaded program. */
adjustment = (u32)rmodule_load_addr(module, 0);
reloc = module->relocations;
num_relocations = rmodule_number_relocations(module);
printk(BIOS_DEBUG, "Processing %d relocs with adjust value of 0x%08x\n",
num_relocations, adjustment);
while (num_relocations > 0) {
u32 *adjust_loc;
if (!rmodule_reloc_valid(reloc))
return -1;
/* If the adjustment location is non-NULL adjust it. */
adjust_loc = rmodule_adjustment_location(module, reloc);
if (adjust_loc != NULL) {
printk(PK_ADJ_LEVEL, "Adjusting %p: 0x%08x -> 0x%08x\n",
adjust_loc, *adjust_loc,
*adjust_loc + adjustment);
*adjust_loc += adjustment;
reloc = remodule_next_reloc(reloc);
return 0;
int rmodule_load_alignment(const struct rmodule *module)
/* The load alignment is the start of the program's linked address.
* The base address where the program is loaded needs to be a multiple
* of the program's starting link address. That way all data alignment
* in the program is presered. */
return module->header->module_link_start_address;
int rmodule_load(void *base, struct rmodule *module)
* In order to load the module at a given address, the following steps
* take place:
* 1. Copy payload to base address.
* 2. Adjust relocations within the module to new base address.
* 3. Clear the bss segment last since the relocations live where
* the bss is. If an rmodule is being loaded from its load
* address the relocations need to be processed before the bss.
module->location = base;
if (rmodule_relocate(module))
return -1;
return 0;
int rmodule_calc_region(unsigned int region_alignment, size_t rmodule_size,
size_t *region_size, int *load_offset)
/* region_alignment must be a power of 2. */
if (region_alignment & (region_alignment - 1))
if (region_alignment < 4096)
region_alignment = 4096;
/* Sanity check rmodule_header size. The code below assumes it is less
* than the minimum alignment required. */
if (region_alignment < sizeof(struct rmodule_header))
/* Place the rmodule according to alignment. The rmodule files
* themselves are packed as a header and a payload, however the rmodule
* itself is linked along with the header. The header starts at address
* 0. Immediately following the header in the file is the program,
* however its starting address is determined by the rmodule linker
* script. In short, sizeof(struct rmodule_header) can be less than
* or equal to the linked address of the program. Therefore we want
* to place the rmodule so that the program falls on the aligned
* address with the header just before it. Therefore, we need at least
* a page to account for the size of the header. */
*region_size = ALIGN(rmodule_size + region_alignment, 4096);
/* The program starts immediately after the header. However,
* it needs to be aligned to a 4KiB boundary. Therefore, adjust the
* program location so that the program lands on a page boundary. The
* layout looks like the following:
* +--------------------------------+ region_alignment + region_size
* | >= 0 bytes from alignment |
* +--------------------------------+ program end (4KiB aligned)
* | program size |
* +--------------------------------+ program_begin (4KiB aligned)
* | sizeof(struct rmodule_header) |
* +--------------------------------+ rmodule header start
* | >= 0 bytes from alignment |
* +--------------------------------+ region_alignment
*load_offset = region_alignment;
return region_alignment - sizeof(struct rmodule_header);