Open in app
Home
Notifications
Lists
Stories

Write
Gabriel Gonzalez
Gabriel Gonzalez

Home

Apr 15, 2015

e-LockPicking: Opening Electronic Doors

I bought this lock under the brand of Tafta but it seems the the original manufacturer, which seems to OEM it, is SoHoMiLL YL-99 Electronic Door (pointed by @revskills). It is basically a lock which runs on batteries and allows the user to store different code entries. The master code…

Embedded Systems

4 min read

e-LockPicking: Opening Electronic Doors
e-LockPicking: Opening Electronic Doors

Jun 21, 2014

Inertial Sensor Side Channel: Guessing Your Unlock Code

Few years back I started thinking about how much information could be extracted from a phone’s inertial sensors to guess some sensitive information such as PIN / UnLock Codes / other passwords. …

Security

6 min read

Inertial Sensor Side Channel: Guessing Your Unlock Code
Inertial Sensor Side Channel: Guessing Your Unlock Code

Jan 8, 2014

Dumping Pebble’s Firmware

Pebble ( http://www.getpebble.com) is a smart-watch pretty popular for rasing more than $10 million from a Kickstarter campaign. Features a STM32 microprocessor as can be seen in wikipedia ( http://en.wikipedia.org/wiki/Pebble_(watch)). Pebble’s update package contains a bootloader image but I wanted to dump what really is on the internal flash. In…

Embedded Systems

6 min read

Dumping Pebble’s Firmware
Dumping Pebble’s Firmware

Sep 16, 2013

Quickly Adapting U-Boot to a Custom Board

Almost every company manufacturing Embedded Systems produce their own boards with their very own peripherals, which of course, need to be initialized when the boards is powered up. They can go from simple leds, to amplifiers or external appliances, but what they usually share is that they depend on GPIOs…

Embedded Systems

2 min read


Feb 5, 2013

netfrag: Limiting tcp/ip packets size

A few days ago I hit an awful bug in the iOS’s TCPI/IP stack which drove me crazy for a while since everything worked fine on other devices except a brand new iPad. The problem appears when UDP packet’s payload is larger than 9200 bytes; Beyond this limit the app…

1 min read


Oct 28, 2012

Debugging U-Boot after relocating to RAM

If some day you find yourself debugging u-boot, or maybe another bootloader, you will probably face a problem when setting breakpoints at some symbols; the application doesn’t stop where you have told the gdb to. Bootloaders usually are written to the system’s flash so the microprocessor starts executing there at…

Embedded Systems

3 min read

Debugging U-Boot after relocating to RAM
Debugging U-Boot after relocating to RAM

Oct 2, 2012

mystrlen vs android-bionic’s strlen on ARM CPU

After my last post I got a request from @trufae asking for a benchmark against Android’s bionic library so there I go. I begun compiling the available bionic’s strlen version and running the same test as in my previous post. The first thing I noticed reading the bionic’s strlen version…

Embedded Systems

4 min read

mystrlen vs android-bionic’s strlen on ARM CPU
mystrlen vs android-bionic’s strlen on ARM CPU

Oct 1, 2012

strchr() optimized for ARM and performance analysis

Note: This optimization are for an ARMv5 processor (arm926ejs) further improvement could be achieved in a newer ARM versions The next function I want to play with is strchr() used for locating a char in a given string; returns a pointer to the first occurrence of the character or NULL…

Embedded Systems

4 min read

strchr() optimized for ARM and performance analysis
strchr() optimized for ARM and performance analysis

Sep 27, 2012

ARM Optimized strlen()

Few weeks ago I started a personal project to enable lua programming under u-boot to allow easy access of peripherals and create small embeddable initialization scripts which I have missed during professional Embedded Development. Another goal of this projects is to optimize u-boot’s ARM code so the first optimization go…

Embedded Systems

3 min read

ARM Optimized strlen()
ARM Optimized strlen()

Oct 3, 2011

Papers of the Month: Detecting RF Devices & Embedded Multi-Core

The paper presents a series of techniques which goal is to detect the presence of RF signal from different devices such as bluetooth, Zigbee, etc. They main contributions is the use of commodity WiFi adapters which allows anyone to use the solution proposed. The image below show an schematic view…

Security

2 min read

Papers of the Month: Detecting RF Devices & Embedded Multi-Core
Papers of the Month: Detecting RF Devices & Embedded Multi-Core
Gabriel Gonzalez

Gabriel Gonzalez

Help

Status

Writers

Blog

Careers

Privacy

Terms

About

Knowable