cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ar7part.c (3362B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright © 2007 Eugene Konev <ejka@openwrt.org>
      4 *
      5 * TI AR7 flash partition table.
      6 * Based on ar7 map by Felix Fietkau <nbd@openwrt.org>
      7 */
      8
      9#include <linux/kernel.h>
     10#include <linux/slab.h>
     11
     12#include <linux/mtd/mtd.h>
     13#include <linux/mtd/partitions.h>
     14#include <linux/memblock.h>
     15#include <linux/module.h>
     16
     17#include <uapi/linux/magic.h>
     18
     19#define AR7_PARTS	4
     20#define ROOT_OFFSET	0xe0000
     21
     22#define LOADER_MAGIC1	le32_to_cpu(0xfeedfa42)
     23#define LOADER_MAGIC2	le32_to_cpu(0xfeed1281)
     24
     25struct ar7_bin_rec {
     26	unsigned int checksum;
     27	unsigned int length;
     28	unsigned int address;
     29};
     30
     31static int create_mtd_partitions(struct mtd_info *master,
     32				 const struct mtd_partition **pparts,
     33				 struct mtd_part_parser_data *data)
     34{
     35	struct ar7_bin_rec header;
     36	unsigned int offset;
     37	size_t len;
     38	unsigned int pre_size = master->erasesize, post_size = 0;
     39	unsigned int root_offset = ROOT_OFFSET;
     40
     41	int retries = 10;
     42	struct mtd_partition *ar7_parts;
     43
     44	ar7_parts = kcalloc(AR7_PARTS, sizeof(*ar7_parts), GFP_KERNEL);
     45	if (!ar7_parts)
     46		return -ENOMEM;
     47	ar7_parts[0].name = "loader";
     48	ar7_parts[0].offset = 0;
     49	ar7_parts[0].size = master->erasesize;
     50	ar7_parts[0].mask_flags = MTD_WRITEABLE;
     51
     52	ar7_parts[1].name = "config";
     53	ar7_parts[1].offset = 0;
     54	ar7_parts[1].size = master->erasesize;
     55	ar7_parts[1].mask_flags = 0;
     56
     57	do { /* Try 10 blocks starting from master->erasesize */
     58		offset = pre_size;
     59		mtd_read(master, offset, sizeof(header), &len,
     60			 (uint8_t *)&header);
     61		if (!strncmp((char *)&header, "TIENV0.8", 8))
     62			ar7_parts[1].offset = pre_size;
     63		if (header.checksum == LOADER_MAGIC1)
     64			break;
     65		if (header.checksum == LOADER_MAGIC2)
     66			break;
     67		pre_size += master->erasesize;
     68	} while (retries--);
     69
     70	pre_size = offset;
     71
     72	if (!ar7_parts[1].offset) {
     73		ar7_parts[1].offset = master->size - master->erasesize;
     74		post_size = master->erasesize;
     75	}
     76
     77	switch (header.checksum) {
     78	case LOADER_MAGIC1:
     79		while (header.length) {
     80			offset += sizeof(header) + header.length;
     81			mtd_read(master, offset, sizeof(header), &len,
     82				 (uint8_t *)&header);
     83		}
     84		root_offset = offset + sizeof(header) + 4;
     85		break;
     86	case LOADER_MAGIC2:
     87		while (header.length) {
     88			offset += sizeof(header) + header.length;
     89			mtd_read(master, offset, sizeof(header), &len,
     90				 (uint8_t *)&header);
     91		}
     92		root_offset = offset + sizeof(header) + 4 + 0xff;
     93		root_offset &= ~(uint32_t)0xff;
     94		break;
     95	default:
     96		printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
     97		break;
     98	}
     99
    100	mtd_read(master, root_offset, sizeof(header), &len, (u8 *)&header);
    101	if (header.checksum != SQUASHFS_MAGIC) {
    102		root_offset += master->erasesize - 1;
    103		root_offset &= ~(master->erasesize - 1);
    104	}
    105
    106	ar7_parts[2].name = "linux";
    107	ar7_parts[2].offset = pre_size;
    108	ar7_parts[2].size = master->size - pre_size - post_size;
    109	ar7_parts[2].mask_flags = 0;
    110
    111	ar7_parts[3].name = "rootfs";
    112	ar7_parts[3].offset = root_offset;
    113	ar7_parts[3].size = master->size - root_offset - post_size;
    114	ar7_parts[3].mask_flags = 0;
    115
    116	*pparts = ar7_parts;
    117	return AR7_PARTS;
    118}
    119
    120static struct mtd_part_parser ar7_parser = {
    121	.parse_fn = create_mtd_partitions,
    122	.name = "ar7part",
    123};
    124module_mtd_part_parser(ar7_parser);
    125
    126MODULE_LICENSE("GPL");
    127MODULE_AUTHOR(	"Felix Fietkau <nbd@openwrt.org>, "
    128		"Eugene Konev <ejka@openwrt.org>");
    129MODULE_DESCRIPTION("MTD partitioning for TI AR7");