Jithin Jith

I've been installing and testing a lot of custom ROMs recently on my Redmi 2. This is a brief tutorial describing all the steps involved in installing a custom ROM (with specific steps required for Redmi 2).

Before proceeding, make sure you have backed up all your important data to another device.

fastboot flash recovery /path/to/twrp/image

fastboot boot /path/to/twrp/image

This is a small python script which I wrote for easy login to netaccess at IIT Madras. The script is pretty self-explanatory. I wrote this when I was trying to learn the requests module for python. The script uses the requests module to communicate with the netaccess site. It also uses the user agent string of a browser to make the netaccess site think that it's dealing with a browser. Note that you can set a default username in get_login_data() function. Set it to your roll number so that you don't have to enter it every time you call the script. The password has to be entered manually because I didn't want to store it in plain text.

PS: Remember to put the script in your $PATH for ease of use.

#!/usr/bin/env python
from __future__ import print_function, division
import requests
import getpass
import sys


def get_login_data():
    '''Asks the user for the username and password. Returns a dictionary to be
    passed to the /account/login post request.
    '''

    username = input('Enter username (Empty input defaults to "am12d013"): ')

    if not username:
        username = 'am12d013'

    password = ''

    while not password:
        password = getpass.getpass('Enter password (Cannot be empty): ')

    #return {'username': username, 'password': password}
    return {'userLogin': username, 'userPassword': password}


def get_approve_data():
    '''Asks the user for the duration to be logged in for. Returns a dictionary
    to be passed to the /account/approve post request.
    '''

    duration = input('Enter session duration (1: 1 hour, 2: 1 day, empty defaults to 1): ')

    if (not duration) or (duration!='2'):
        duration = '1'

    if duration == '1':
        print('You have requested approval for 1 hour')
    else:
        print('You have requested approval for 1 day')

    return {'duration': duration, 'approveBtn': ''}


def has_logged_in(response):
    '''Checks if login request is successful. Returns false if not.
    '''
    # If response is not 200 OK, raise error
    if response.status_code != requests.codes.ok:
        response.raise_for_status()
    # Check if login has failed by searching for a substring in the response
    # content
    elif '/account/approve' not in response.content:
        return False

    return True


def main():

    # User agent string from Firefox 49 running on a Linux machine
    headers = {'User-Agent': 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:49.0) Gecko/20100101 Firefox/49.0'}

    login_data = get_login_data()
    approve_data = get_approve_data()

    with requests.Session() as s:

        # Login request
        p = s.post('https://netaccess.iitm.ac.in/account/login',
                data=login_data, headers=headers)

        # Check if login is successful.
        if has_logged_in(p):
            print('Login successful.')
        else:
            print('Wrong username or password provided. Login failed!')
            sys.exit(0)

        # Approve machine request
        p = s.post('https://netaccess.iitm.ac.in/account/approve',
                data=approve_data, headers=headers)

        # If response is not 200 OK, approval has failed. Exit.
        if p.status_code != requests.codes.ok:
            p.raise_for_status()
        else:
            print('Machine approved successfully.')

        sys.exit(0)


if __name__ == '__main__':

    # If python2.x, use 'raw_input' else use 'input'
    try:
        input = raw_input
    except NameError:
        pass

    main()

Say, you want spotlight to find MacVim. Doing

$ brew linkapps macvim

creates a symlink in /Applications. But Spotlight seems to ignore it. Instead, remove the symlink

$ rm /Applications/MacVim.app

and do

$ osascript -e 'tell application "Finder" to make alias file to POSIX file "/usr/local/opt/macvim/MacVim.app" at POSIX file "/Applications"'

• Install build dependencies

$ sudo apt-get build-dep vim

• Clone git repo

$ git clone https://github.com/vim/vim.git``

• Change to src directory

$ cd vim/src

• Remove files from previous compilation (skip if compiling for the first time)

$ sudo make distclean

• Path to install vim (optional. omit --prefix option in next step if not set)

export PREFIX='/path/to/vim/install'

• Configure with required options ($ configure --help for other config. options).

  • For python 2.x

  $ ./configure --with-features=huge \
              --enable-multibyte \
              --enable-rubyinterp \
              --enable-pythoninterp \
              --with-python-config-dir=/usr/lib/python2.7/config-x86\_64-linux-gnu \
              --enable-perlinterp \
              --enable-luainterp \
              --enable-cscope \
              --enable-gui=auto \
              --enable-gtk2-check \
              --with-x \
              --with-compiledby="j.jith" \
              --prefix=$PREFIX
  

  • For python 3.x

  $ ./configure --with-features=huge \
              --enable-multibyte \
              --enable-rubyinterp \
              --enable-python3interp \
              --with-python3-config-dir=/usr/lib/python3.5/config-3.5m-x86_64-linux-gnu \
              --enable-perlinterp \
              --enable-luainterp \
              --enable-cscope \
              --enable-gui=auto \
              --enable-gtk2-check \
              --with-x \
              --with-compiledby="j.jith" \
              --prefix=$PREFIX
  

• Compile

$ make

• Run tests

$ make test

• Install (may need to use sudo if you don't have write permission in $PREFIX)

$ make install

• Make default editor/vim/vi/gvim

$ sudo sh -c "update-alternatives --install /usr/bin/editor editor $PREFIX/bin/vim 1;
update-alternatives --set editor $PREFIX/bin/vim;
update-alternatives --install /usr/bin/vim vim $PREFIX/bin/vim 1;
update-alternatives --set vim $PREFIX/bin/vim;
update-alternatives --install /usr/bin/vi vi $PREFIX/bin/vim 1;
update-alternatives --set vi $PREFIX/bin/vim;
update-alternatives --install /usr/bin/gvim gvim $PREFIX/bin/gvim 1;
update-alternatives --set gvim $PREFIX/bin/gvim"

• Download the ROM suitable for your device from the MIUI site and extract the downloaded archive
• Download and extract the Android SDK Platform Tools
• Make sure adb and fastboot (components of platform-tools) are in your path

$ export PATH=path/to/android/sdk/platform-tools:$PATH

• Connect your device to your computer using a USB cable and enable USB Debugging in your device's settings. Check if your device is detected.

$ adb devices

• If device is listed, reboot to bootloader

$ adb reboot bootloader

• Check if your device is detected by fastboot

$ fastboot devices

• You may need to use sudo before fastboot if you get a permission denied error
• There are two scripts for flashing the ROM:
  1. flash_all.sh - Flash ROM and erase user data
  2. flash_all_except_data_storage.sh - Flash ROM without erasing user data
• Whichever script you decide to use, make sure that the interpreter is mentioned at the top of the script like

#!/bin/sh

• If the above line is missing, add it to the top of the script
• Make the script executable (I've chosen flash_all.sh)

$ cd path/to/extracted/ROM/archive
$ chmod a+x ./flash_all.sh

• Run the script

$ ./flash_all.sh

• You may need to run sudo ./flash_all.sh if you had to use sudo with fastboot
• Sit back and relax. The script needs no user interaction. After flashing the ROM, the scipt will reboot your device.
• Reboot will take quit a bit of time. Don't panic.