/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2003 Eric W. Biederman <ebiederm@xmission.com>
 * Copyright (C) 2009 Ron Minnich <rminnich@gmail.com>
 * Copyright (C) 2016 George Trudeau <george.trudeau@usherbrooke.ca>
 *
 * 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 <commonlib/compression.h>
#include <commonlib/endian.h>
#include <console/console.h>
#include <cpu/cpu.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <symbols.h>
#include <cbfs.h>
#include <lib.h>
#include <bootmem.h>
#include <program_loading.h>
#include <timestamp.h>

struct segment {
	struct segment *next;
	struct segment *prev;
	unsigned long s_dstaddr;
	unsigned long s_srcaddr;
	unsigned long s_memsz;
	unsigned long s_filesz;
	int compression;
};

/* Decode a serialized cbfs payload segment
 * from memory into native endianness.
 */
static void cbfs_decode_payload_segment(struct cbfs_payload_segment *segment,
					const struct cbfs_payload_segment *src)
{
	segment->type = read_be32(&src->type);
	segment->compression = read_be32(&src->compression);
	segment->offset = read_be32(&src->offset);
	segment->load_addr = read_be64(&src->load_addr);
	segment->len = read_be32(&src->len);
	segment->mem_len = read_be32(&src->mem_len);
}

static int
load_segment(struct segment *ptr)
{
	unsigned char *dest, *src, *end;
	size_t len, memsz;

	printk(BIOS_DEBUG,
	       "Loading Segment: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
	       ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
	/* Compute the boundaries of the segment */
	dest = (unsigned char *)(ptr->s_dstaddr);
	src = (unsigned char *)(ptr->s_srcaddr);
	len = ptr->s_filesz;
	memsz = ptr->s_memsz;
	end = dest + memsz;

	switch (ptr->compression) {
	case CBFS_COMPRESS_LZMA: {
		printk(BIOS_DEBUG, "using LZMA\n");
		timestamp_add_now(TS_START_ULZMA);
		len = ulzman(src, len, dest, memsz);
		timestamp_add_now(TS_END_ULZMA);
		if (!len) /* Decompression Error. */
			return 0;
		break;
	}
	case CBFS_COMPRESS_LZ4: {
		printk(BIOS_DEBUG, "using LZ4\n");
		timestamp_add_now(TS_START_ULZ4F);
		len = ulz4fn(src, len, dest, memsz);
		timestamp_add_now(TS_END_ULZ4F);
		if (!len) /* Decompression Error. */
			return 0;
		break;
	}
	case CBFS_COMPRESS_NONE: {
		printk(BIOS_DEBUG, "it's not compressed!\n");
		memcpy(dest, src, len);
		break;
	}
	default:
		printk(BIOS_INFO, "CBFS:  Unknown compression type %d\n",
		       ptr->compression);
		return -1;
	}
	return 0;
}

/* This loads the payload from a romstage.
 * This is different than the ramstage payload loader since we don't
 * check memory regions and we don't use malloc anywhere. It is most like
 * the LinuxBIOS v3 SELF loader.
 */
static int load_payload(
	struct segment *head,
	struct cbfs_payload *cbfs_payload, uintptr_t *entry)
{
	struct segment *new;
	struct cbfs_payload_segment *current_segment, *first_segment, segment;
	struct segment ptr;

	memset(head, 0, sizeof(*head));
	head->next = head->prev = head;

	first_segment = &cbfs_payload->segments;

	for (current_segment = first_segment;; ++current_segment) {
		printk(BIOS_DEBUG,
		       "Decoding segment from ROM address 0x%p\n",
		       current_segment);

		cbfs_decode_payload_segment(&segment, current_segment);

		switch (segment.type) {
		case PAYLOAD_SEGMENT_PARAMS:
			printk(BIOS_DEBUG, "  parameter section (skipped)\n");
			continue;

		case PAYLOAD_SEGMENT_CODE:
		case PAYLOAD_SEGMENT_DATA:
			printk(BIOS_DEBUG, "  %s (compression=%x)\n",
			       segment.type == PAYLOAD_SEGMENT_CODE
				       ? "code"
				       : "data",
			       segment.compression);

			new = &ptr;
			new->s_dstaddr = segment.load_addr;
			new->s_memsz = segment.mem_len;
			new->compression = segment.compression;
			new->s_srcaddr = (uintptr_t)((unsigned char *)first_segment)
					 + segment.offset;
			new->s_filesz = segment.len;

			printk(BIOS_DEBUG,
			       "  New segment dstaddr 0x%lx memsize 0x%lx srcaddr 0x%lx filesize 0x%lx\n",
			       new->s_dstaddr, new->s_memsz, new->s_srcaddr,
			       new->s_filesz);

			/* Clean up the values */
			if (new->s_filesz > new->s_memsz) {
				new->s_filesz = new->s_memsz;
				printk(BIOS_DEBUG,
				       "  cleaned up filesize 0x%lx\n",
				       new->s_filesz);
			}
			load_segment(new);
			break;

		case PAYLOAD_SEGMENT_BSS:
			printk(BIOS_DEBUG, "  BSS 0x%p (%d byte)\n", (void *)(intptr_t)segment.load_addr, segment.mem_len);

			new = &ptr;
			new->s_filesz = 0;
			new->s_srcaddr = (uintptr_t)((unsigned char *)first_segment)
					 + segment.offset;
			new->s_dstaddr = segment.load_addr;
			new->s_memsz = segment.mem_len;
			new->compression = CBFS_COMPRESS_NONE;
			load_segment(new);
			break;

		case PAYLOAD_SEGMENT_ENTRY:
			printk(BIOS_DEBUG, "  Entry Point 0x%p\n", (void *)(intptr_t)segment.load_addr);

			*entry = segment.load_addr;
			/* Per definition, a payload always has the entry point
			 * as last segment. Thus, we use the occurrence of the
			 * entry point as break condition for the loop.
			 * Can we actually just look at the number of section?
			 */
			return 1;

		default:
			/* We found something that we don't know about. Throw
			 * hands into the sky and run away!
			 */
			printk(BIOS_EMERG, "Bad segment type %x\n",
			       segment.type);
			return -1;
		}
	}

	return 1;
}

bool selfload(struct prog *payload, bool check_regions)
{
	uintptr_t entry = 0;
	struct segment head;
	void *data;

	data = rdev_mmap_full(prog_rdev(payload));
	if (data == NULL)
		return false;

	/* Load the segments */
	if (!load_payload(&head, data, &entry))
		return false;

	prog_set_entry(payload, (void *)entry, NULL);
	printk(BIOS_SPEW, "Loaded segments\n");
	return true;
}