Do Smartphones Have BIOS?
In this article, we’ll discuss if the smartphones have BIOS aka the basic input/output system, typically found in the personal computers.
TLDR; the smartphones do not have BIOS, but they have an equivalent called ‘bootloader’. The bootloader is a program that boots the operating system of the device. It instructs the device what programs to load in order to make the device operational.
But before we get into that, let’s start with the basics.
Understanding BIOS and its Functionality in Smartphones
A Basic Input/Output System (BIOS) is a low-level software embedded on a device's motherboard that handles the initial power-on and start-up processes of a computer.
Traditionally, BIOS is a term associated with traditional PCs (Personal Computers), where it acts as the intermediary between the hardware and the operating system.
Smartphones have Bootloader in place of the BIOS. Let’s pay attention to how it works-
The Smartphone Bootloader: BIOS Equivalent in Smartphones
Just like a PC needs the BIOS to understand how to load the OS from the hard disk, a smartphone requires a bootloader to load the OS into the device's memory.
A bootloader is firmware that is embedded into the hardware of a smartphone and is the first code that runs when a smartphone is powered on.
The bootloader is responsible for checking and initializing the hardware components and then loading the operating system kernel into memory. This kernel, in turn, handles the rest of the boot process.
The bootloader also provides a mode for users to interface directly with the system, usually for troubleshooting, device updates, or system recovery.
The bootloader is specific to the hardware on the device, which is why every smartphone has a different bootloader.
This is also the reason why you cannot just install any OS on your smartphone. The OS must be compatible with the bootloader on that device, which can limit the types of OS a smartphone can use.
The Boot Process in Smartphones
When you turn on your smartphone, it's not immediately ready to run applications. The hardware needs to be checked, the software needs to be loaded, and various other processes must happen before you can start using the device.
Power On: The smartphone's power button triggers the bootloader.
Bootloader Launches: The bootloader checks the device's hardware and initializes all the components, ensuring they're functioning correctly. This involves initializing the CPU, checking memory, and setting up other hardware peripherals.
OS Loading: After the hardware check, the bootloader loads the device's kernel, a vital part of the OS that communicates between the software and hardware. The kernel is responsible for memory management, process management, and handling system calls.
System Initialization: Once the kernel is loaded, it starts the system server which loads the system libraries and starts up the Android runtime. The system server also starts key system services such as telephony and package management.
User Interface: After the system initialization, the user interface, which includes things like the home screen and applications menu, loads. At this point, the phone is ready for use.
I hope this answers your question. Do let me know if you have follow-up questions.
Replies
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Abhishek RawalYeah smartphones do have bios.
During initial period of smartphone, the OS were embedded in the microchips.
Now a days flash memory is used, so OS can be replaced or updated . We call it firmware.
You might have heard of ROMs in androids. The stock firmware is replaced by 3rd party firmware by flashing the bios. -
Anoop KumarI think Android devices doesn't have any BIOS.
Kernel is replacing this and managing hardware initialization.
Architecture of Android OS
![[IMG]](proxy.php?image=http%3A%2F%2Fsource.android.com%2Ftech%2Fsecurity%2Fimages%2Fimage00.png&hash=563b5818b7c44239ba31a044bfc48385)
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Abhishek RawalEven kernel needs BIOS interrupts. But once kernel is started it won't need Bios.
kernel need not to be confused with basic input output system.
Kernel is part of OS.
While Bios tells everything what to do.
Yeah everything!! It is the boss.
Some kernel are developed independent but still it needs BIOS to start. Once it will start, bios is not needed for computation. -
Anoop KumarI have posted this question #-Link-Snipped-#
Android Booting - eLinux.org
Not sure Bootloader is part of kernel or ROM 😒 -
VIJAYSYwhether os of smartphone is machine dependent?
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Anoop Kumar
Yes...VIJAYSYwhether os of smartphone is machine dependent? -
Kaustubh KatdareI think it's pretty logical to derive that most of the software+hardware systems would need a BIOS (which is what it is - a basic input and output system). Once you boot your device (let's say you pass electric current) the system needs to perform whether it's got everything it needs to function. That's BIOS in the simplest of the words.
Of course, the firmware or the operating system would be dependent on the hardware. But many times, since the basic structure of the systems is more or less the same; you can port one OS to another; but it requires lot of tweaks. The basic OS+Hardware interaction remains the same, as far as I know. I'd like to hear more insights on this.
Just out of curiosity - has there been a successful port of Android on iPhone / iPad and port of iOS on any Android powered phone? -
Rishav RakshitThe Bootloader is basically the BIOS in our smartphones. You may have noticed when we do a botched up flash of the Bootloader the phone gets bricked. This is because a corrupt bootloader fails to load the firmware.
So, why don't Smartphone makers just call it BIOS?
Cause it's not. In a PC for example, the BIOS does not load the OS directly. It loads the Bootmanager, which in turn loads the OS. Since in Smartphones resources are limited, both the Bootmanager and BIOS is combined into a single proprietary Bootloader, saving a ton of code and resource management required for cross-compatibility (running Windows, Linux, Unix etc. on the same motherboard setup) . This is also the reason why Android cannot be simply installed on an iOS device and vice-versa.
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