text: /*
   * 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
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  #include <assert.h>
  #include <cbmem.h>
  #include <cbfs.h>
  #include <stdint.h>
  #include <stdlib.h>
  #include <string.h>
  #include <lib.h>
  #include <console/console.h>
  #include <program_loading.h>
  #include <rmodule.h>
  
  /* Change this define to get more verbose debugging for module loading. */
  #define PK_ADJ_LEVEL BIOS_NEVER
  
  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,
  				      uintptr_t 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 -
  				rhdr->payload_begin_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 -
  	       module->header->module_link_start_address;
  }
  
  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 size_t rmodule_number_relocations(const struct rmodule *module)
  {
  	size_t r;
  
  	r = module->header->relocations_end_offset;
  	r -= module->header->relocations_begin_offset;
  	r /= sizeof(uintptr_t);
  	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)
  		return;
  
  	memcpy(module->location, module->payload, module->payload_size);
  }
  
  static int rmodule_relocate(const struct rmodule *module)
  {
  	size_t num_relocations;
  	const uintptr_t *reloc;
  	uintptr_t adjustment;
  
  	/* Each relocation needs to be adjusted relative to the beginning of
  	 * the loaded program. */
  	adjustment = (uintptr_t)rmodule_load_addr(module, 0);
  
  	reloc = module->relocations;
  	num_relocations = rmodule_number_relocations(module);
  
  	printk(BIOS_DEBUG, "Processing %zu relocs. Offset value of 0x%08lx\n",
  	       num_relocations, (unsigned long)adjustment);
  
  	while (num_relocations > 0) {
  		uintptr_t *adjust_loc;
  
  		/* If the adjustment location is non-NULL adjust it. */
  		adjust_loc = rmodule_load_addr(module, *reloc);
  		printk(PK_ADJ_LEVEL, "Adjusting %p: 0x%08lx -> 0x%08lx\n",
  		       adjust_loc, (unsigned long) *adjust_loc,
  		       (unsigned long) (*adjust_loc + adjustment));
  			*adjust_loc += adjustment;
  
  		reloc++;
  		num_relocations--;
  	}
  
  	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 preserved. Default to 4KiB. */
  	return 4096;
  }
  
  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;
  	rmodule_copy_payload(module);
  	if (rmodule_relocate(module))
  		return -1;
  	rmodule_clear_bss(module);
  
  	prog_segment_loaded((uintptr_t)module->location,
  				rmodule_memory_size(module), SEG_FINAL);
  
  	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))
  		BUG();
  
  	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))
  		BUG();
  
  	/* 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);
  }
  
  int rmodule_stage_load(struct rmod_stage_load *rsl)
  {
  	struct rmodule rmod_stage;
  	size_t region_size;
  	char *stage_region;
  	int rmodule_offset;
  	int load_offset;
  	struct cbfs_stage stage;
  	void *rmod_loc;
  	struct region_device *fh;
  
  	if (rsl->prog == NULL || prog_name(rsl->prog) == NULL)
  		return -1;
  
  	fh = prog_rdev(rsl->prog);
  
  	if (rdev_readat(fh, &stage, 0, sizeof(stage)) != sizeof(stage))
  		return -1;
  
  	rmodule_offset =
  		rmodule_calc_region(DYN_CBMEM_ALIGN_SIZE,
  				    stage.memlen, &region_size, &load_offset);
  
  	stage_region = cbmem_add(rsl->cbmem_id, region_size);
  
  	if (stage_region == NULL)
  		return -1;
  
  	rmod_loc = &stage_region[rmodule_offset];
  
  	printk(BIOS_INFO, "Decompressing stage %s @ 0x%p (%d bytes)\n",
  	       prog_name(rsl->prog), rmod_loc, stage.memlen);
  
  	if (!cbfs_load_and_decompress(fh, sizeof(stage), stage.len, rmod_loc,
  				      stage.memlen, stage.compression))
  		return -1;
  
  	if (rmodule_parse(rmod_loc, &rmod_stage))
  		return -1;
  
  	if (rmodule_load(&stage_region[load_offset], &rmod_stage))
  		return -1;
  
  	prog_set_area(rsl->prog, rmod_stage.location,
  			rmodule_memory_size(&rmod_stage));
  
  	/* Allow caller to pick up parameters, if available. */
  	rsl->params = rmodule_parameters(&rmod_stage);
  
  	prog_set_entry(rsl->prog, rmodule_entry(&rmod_stage), rsl->params);
  
  	return 0;
  }
  