lisovy

/*
 * Inpired by https://www.opensource.apple.com/source/xnu/xnu-1456.1.26/osfmk/i386/mtrr.c
 */

#define MTRR_TYPE_UC			0x0
#define MTRR_TYPE_WC			0x1
#define MTRR_TYPE_WT			0x4
#define MTRR_TYPE_WP			0x5
#define MTRR_TYPE_WB			0x6

lisovy

#!/bin/bash

if [ $# -ne 2 ]; then
	echo -e "Usage: $0 FLAC_FILE CUE_FILE\n"
	exit 1;
fi

FLAC_FILE=$1
CUE_FILE=$2

lisovy

#!/bin/bash

for (( i=1 ; $i-10; i=$i+1 ))
do
	sleep 0.5s; 
	clear
	echo -e ' oo\n<|>\n_|_';
	
	sleep 0.5s; 
	clear

lisovy

Barebox bootloader
==================
sudo apt-get install lzop, libusb-1.0-0-dev

Build it
''''''''
git clone git://git.pengutronix.de/git/barebox.git
cd barebox/
mkdir _build
CROSS_COMPILE=arm-linux-gnueabihf- make ARCH=arm O=_build imx_v7_defconfig

lisovy

12345678901234567890123456789012345678901234567890123456789012345678901234567890
pbuf vs. netbuf
===============
pbuf -- internal representation of a packet (should not be directly accessed
    when using netconn or socket API).
PBUF_POOL -- one struct containing header + data buffer (+ space reserved for
    headers) obtained from a pool of limited amount of statically allocated
    structs (i.e. slab allocator).
    The size of the whole struct is fixed, in case the data are bigger than the
    pre-allocated buffer in a struct, multiple pbufs are chained together

lisovy

http://www.embest-tech.com/shop/star/marsboard.html

U-boot
======
git clone git://git.denx.de/u-boot.git
cd u-boot

# Build U-boot
mkdir _build
make O=_build marsboard_defconfig

lisovy

Program flow tracing (with source modification)
===============================================
* assert()
  Instead of
    if (variable < 0)
        printf(...);
    else
        printf(...);
  use
    assert(variable > 0);

lisovy

Multiplatform programming
=========================
Issues to be aware of:
* Integer types sizes (int -- 16 or 32 bits? long -- 32 or 64 bits?)
  - Storing pointers into integer types
    (unsigned long on 64-bit Linux vs. 64-bit Windows)
* Endianess (big, little)
* Memory access width (byte access, word access)
* Unaligned memory access

lisovy

How to use 'pci pass-through' to run Linux in Qemu accessing real Ath9k adapter
===============================================================================

# Boot kernel with 'intel_iommu=on'

# Unbind driver from the device and bind 'pci-stub' to it
echo "168c 0030" > /sys/bus/pci/drivers/pci-stub/new_id
echo 0000:0b:00.0 > /sys/bus/pci/devices/0000:0b:00.0/driver/unbind
echo 0000:0b:00.0 > /sys/bus/pci/drivers/pci-stub/bind

lisovy

Undefined behavior
==================
http://blog.regehr.org/archives/213

...If any step in a program's execution has undefined behavior,
then the entire execution is without meaning. This is important:
it's not that evaluating (1<<32) has an unpredictable result,
but rather that the entire execution of a program that evaluates
this expression is meaningless. Also, it's not that the execution
is meaningful up to the point where undefined behavior happens: