Xboot Download Chip
Elis Riebow
At this point I am trying to choose a suitable bootloader for the atmega1284p. This is the first time I am using this chip and I have no experience with the available bootloaders. I ve been using just the 32u4 with the arduino micro bootloader so far.
I have been using xboot, after having issues that ended up not being the bootloader at all (it was my RS-422 stuff), but while struggling I tried xboot and have just kept using it. This very simple Makefile is used to run avrdude, it should have the info you would need for the Arduino IDE.
I compiled xboot with the toolchain on Ubuntu 16.04 (same as I use for my project files). Alex helped me, I could not figure out how to run the xboot makefile with a config file, but it is obvious looking back.
I've been seeing various SoCs used for all kinds of interesting projects around the web. Allwinner in particular makes some easily solderable chips, which were used in projects like Simon Richards' V3s board or George Hilliard's My Business Card Runs Linux.
I was wondering if there was any existing RTOS that has some support for these chips? If not, are there any people interested in contributing to such a project if I started one? I see that some of these chips have lacking public documentation, but we can always look at existing Linux drivers. I'd certainly love to contribute to such a project, especially if it was in C++ (like SCMRTOS or distortos).
Original config 9100..last long time. Won't die, runs well...secondary machine.
Reinstalled OS from hidden partition, XP pro and all updates, etc.
A03 BIOS...chipset updates, etc from DELL support site for the 9100.
Moved DVD drive to master, CD drive to slave - to put the DVD in location for boot from
Disabled USB diskette option...and moved DVD to 1st boot option...
If you are actually able to read or write a fuse or lock bit from the AVR without getting errors, that would prove that your connections and chip are working, which would help narrow down the problem a lot.
The SafePal S1 is a cryptocurrency hardware wallet that runs embedded Linux with a system on a chip (SoC). As a result, the architecture of this wallet is different from the microcontroller-based ones that are most popular (e.g., Trezor and Ledger wallets). The challenge in securing any embedded Linux-based system is how to secure the boot process as most, but not all, Linux capable micro-processors require external flash storage and external RAM. Additionally, while Linux may be one of the most extensively used operating systems, it does not ship in a secure state, which requires Safepal to either buy a solution or add hardening themselves.
Both the flash chip and the secure element were potted using an unknown compound. However, heating it with a heat gun made the potting compound brittle. The compound could then be scraped away using a small flat-head screwdriver, without breaking any component of the device. This allows direct access to the SPI pins for further probing.
After establishing the type of flash chip by reading the marking, an attempt was made to dump the flash in-system using flashrom. As the chip was not supported by flashrom at the time of this writing, custom support had to be implemented in flashrom. This allowed gathering a full flash dump.
During further analysis, it was determined that the first 0x8000 or so bytes of the flash are set to read-only using the OTP security functions of the flash chip, while the rest of the flash chip is both readable and writable.
It is likely possible to gain code execution on the device by replacing the main flash chip. As the contents stay identical, this is not detectable by the device. To gain code execution, multiple checks have to be reverse engineered and deobfuscated. While possible, this is especially time consuming, especially given the complexity of the U-Boot obfuscation chain, and was therefore not done as part of this audit.
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