xref: /openbmc/u-boot/tools/rkcommon.c (revision 5be93569)
1 /*
2  * (C) Copyright 2015 Google,  Inc
3  * Written by Simon Glass <sjg@chromium.org>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  *
7  * Helper functions for Rockchip images
8  */
9 
10 #include "imagetool.h"
11 #include <image.h>
12 #include <rc4.h>
13 #include "mkimage.h"
14 #include "rkcommon.h"
15 
16 enum {
17 	RK_SIGNATURE		= 0x0ff0aa55,
18 };
19 
20 /**
21  * struct header0_info - header block for boot ROM
22  *
23  * This is stored at SD card block 64 (where each block is 512 bytes, or at
24  * the start of SPI flash. It is encoded with RC4.
25  *
26  * @signature:		Signature (must be RKSD_SIGNATURE)
27  * @disable_rc4:	0 to use rc4 for boot image,  1 to use plain binary
28  * @init_offset:	Offset in blocks of the SPL code from this header
29  *			block. E.g. 4 means 2KB after the start of this header.
30  * Other fields are not used by U-Boot
31  */
32 struct header0_info {
33 	uint32_t signature;
34 	uint8_t reserved[4];
35 	uint32_t disable_rc4;
36 	uint16_t init_offset;
37 	uint8_t reserved1[492];
38 	uint16_t init_size;
39 	uint16_t init_boot_size;
40 	uint8_t reserved2[2];
41 };
42 
43 static unsigned char rc4_key[16] = {
44 	124, 78, 3, 4, 85, 5, 9, 7,
45 	45, 44, 123, 56, 23, 13, 23, 17
46 };
47 
48 int rkcommon_set_header(void *buf, uint file_size)
49 {
50 	struct header0_info *hdr;
51 
52 	if (file_size > CONFIG_ROCKCHIP_MAX_SPL_SIZE)
53 		return -ENOSPC;
54 
55 	memset(buf,  '\0', RK_INIT_OFFSET * RK_BLK_SIZE);
56 	hdr = (struct header0_info *)buf;
57 	hdr->signature = RK_SIGNATURE;
58 	hdr->disable_rc4 = 1;
59 	hdr->init_offset = RK_INIT_OFFSET;
60 
61 	hdr->init_size = (file_size + RK_BLK_SIZE - 1) / RK_BLK_SIZE;
62 	hdr->init_size = (hdr->init_size + 3) & ~3;
63 	hdr->init_boot_size = hdr->init_size + RK_MAX_BOOT_SIZE / RK_BLK_SIZE;
64 
65 	rc4_encode(buf, RK_BLK_SIZE, rc4_key);
66 
67 	return 0;
68 }
69