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I am currently going through tutorials explaining how to install linux kernel on the raspberry pi, most of the tutorial (an example) recommend the use of an SD card and to install the kernel on it. so I want to ask:

  • Does the Raspberry contain a Flash memory and if yes could you give me a reference on how to install directly the Linux on the Flash (without using an SD card)

  • Where the Bootloader of the Raspberry is installed ? How can we change the bootloader ?

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The Pi A, B, A+, B+, 2B, 3B, 3B+, zero, zero wireless do not have flash memory, they are booted from SD card. The compute modules have 4GB of flash and no SD card slot (thanks @MichaelHampton).

The boot loader is contained in the SoC. We can not change the boot loader.

You can boot the Pi3B and Pi3B+ from USB as well as from the SD card as the SoC on those devices has an appropriate boot loader (I have not used this feature myself).

On other Pis (compute modules excepted) you can also put just bootcode.bin on a SD card and the image on a USB drive (thanks @JaromandaX). This is pretty close to effectively booting from USB.

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  • as a side note, for Pi 1 & 2 you can also put just bootcode.bin on a SD card and the full raspbian image on a USB drive, and effectively boot from USB on earlier Pi's Commented Jul 25, 2018 at 23:20
  • Another side note to boot from USB - I have used this feature on a Pi3B, using a Toshiba USB3.0 thumb drive - and the results were absolutely appalling - disk read/write speeds were pathetic - not sure what's at fault (probably the thumb drive, though it is a USB 3.0 drive and is appropriately fast when used in MSWindows) Commented Jul 25, 2018 at 23:24
  • @JaromandaX That's because the USB ports are USB 2.0. Commented Jul 25, 2018 at 23:49
  • The compute modules have 4GB of flash, but no SD card slot. The flash takes the place of the SD card in a regular RPi. Commented Jul 25, 2018 at 23:51
  • @MichaelHampton - I understand that I wouldn't get USB3.0 speeds, but a USB3.0 thumb drive should at least achieve USB2.0 speeds in a USB2.0 system, but the speeds I was getting (unmeasured, however) made the system virtually unusable - it may well be that the Pi accesses a USB3.0 thumb drive slower than it would a USB2.0 thumb drive - or it may be the particular thumb drive itself (Toshiba brand) - I just wanted to add a caveat that booting from USB on Pi may not result in a particularly useful system :p Commented Jul 26, 2018 at 0:03

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