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c3a62cee96
Before it jumps to an image, the rk27xx NAND bootloader writes three words at the address in RKW header field 0x14: a magic, its version and which copy of the image it loaded. The original firmware never initialises them: it reports the version over USB and counts its own reboots in the third word, and once the count reaches 5 it reboots into a mode the NAND bootloader will not boot. When our bootloader started the OF, nothing wrote them, so the OF ran with whatever was left in DRAM. Field 0x14 of our own images held a constant taken from some other image. Point it at the last 12 bytes of DRAM, which nothing uses before our bootloader runs. load_rkw() in the bootloader now reads the words there before loading an image, and writes them at the address in the loaded image's header when that lies between the image and the bootloader. Started over USB, it passes version 0. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Change-Id: Ife1d63e361a780c28a9f0626d110552b98bb6b7f
48 lines
2.3 KiB
C
48 lines
2.3 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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*
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* Copyright (C) 2012 Marcin Bukat
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 1
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include <stdint.h>
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#define RKLD_MAGIC 0x4c44524b
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#define RKW_HEADER_CRC 0x40000000
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#define RKW_IMAGE_CRC 0x20000000
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struct rkw_header_t {
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uint32_t magic_number; /* Magic number. 0x4C44524B */
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uint32_t header_size; /* Size of the header */
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uint32_t image_base; /* Base address of the firmware image */
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uint32_t load_address; /* Load address */
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uint32_t load_limit; /* End of the firmware image */
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uint32_t handoff; /* Where the loader leaves its three handoff
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* words for the image (see rkw-loader.c)
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*/
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uint32_t reserved0; /* reserved - I've seen only zeros in this field so far */
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uint32_t reserved1; /* reserved - I've seen only zeros in this field so far */
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uint32_t entry_point; /* Entry point address */
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uint32_t load_options; /* 0x80000000 - setup flag (I don't know what it means
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* but is present in every RKW I saw),
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* 0x40000000 - check header crc,
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* 0x20000000 - check firmware crc
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*/
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uint32_t crc; /* crc32 of the header (excluding crc32 field itself) */
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};
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const char *rkw_strerror(int8_t errno);
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int load_rkw(unsigned char* buf, const char* filename, int buffer_size);
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