Why do phones still have ROMs?

[SionicIon]

Ok, I may have not phrased the question right because I think I read even PCs have them. But my question is, why are the operating system files on a modern phones contained in a ROM, when these phones are just as powerful as yesterday computers with Core 2 Quad processors and 1 or 2GBs or RAM? Is there really a big difference between an SSD or a flash chip? Both hold files like a HDD does, and that is partitioned with a system partition where all the system files are including your own files. When we switched from HDD to SSD, that didn't change, even though the storage in a phone is very similar to an SSD, phones still use ROMs.

 

Is it a limitation of the ARM architecture? Once we have x86 phones with an Intel SOC, will ROMs be a thing of the past?

 

Our computers can dual-boot, restore from a recovery partition, hold personal files on the system partition, allow you to create a new partition and have your files over there.

 

Phones don't really install OSs, you kinda just flash a ROM, no partitioning or formatting or processing an actual install, it's just doing a file operation from a recovery ROM to kinda put itself there.

 

Although a blurred line I've seen is on my Surface 2, it does have all the regular partitions, its kinda neat seeing all that on an ARM device for once. But then is Windows RT on my Surface really a ROM flashed to it, or was it installed there but it's still locked down so I can't modify or change system files? Also is Windows Phone 8.1 a ROM on my Lumia 1520? Or is it like Windows RT and it is actually installed on a actual partition?

 

 

Lots of questions I know, I'm just very curious haha. :)

[sanctified Veteran]

Maybe my most ignorant question today, but: are we sure phones really uses roms for operating systems? If so, how can we update them? Does the phones include rom burners? or the patches are held in memory and loaded at start?

[AeonicVision]

I'm having difficulty understanding the question... ROM stands for 'Read Only Memory,' which generally means that it is a part of storage that does not change, that is not updated nor re-flashed (usually).

 

As for why phones use a 'special' type of flash...  I believe it comes down to cost/energy.  The type of NAND storage used in desktop PCs uses more electricity, is faster sometimes, but is also more expensive and larger in size.  Phones are all about small, low energy, and cheap.

 

Does this start to answer your questions?

[Nick H. Supervisor]

I'd be interested in hearing back on this, as for myself I consider ROM these days to be more of an acronym synonymous with phones - Android specifically - but it doesn't really seem to follow the same idea that it used to, as far as I can tell. Then again, my knowledge on the idea is lacking heavily. (Y)

EDIT: Good to know that within the first 30 seconds of this thread, I'm not alone in being a bit confused by the use of the acronym, ROM. :laugh:

[adrynalyne]

I'd be interested in hearing back on this, as for myself I consider ROM these days to be more of an acronym synonymous with phones - Android specifically - but it doesn't really seem to follow the same idea that it used to, as far as I can tell. Then again, my knowledge on the idea is lacking heavily. (Y)

EDIT: Good to know that within the first 30 seconds of this thread, I'm not alone in being a bit confused by the use of the acronym, ROM. :laugh:

Rom is just an antiquated term for OS packages that are flashed even though we have moved on to nand. 

 

OP is confused.

[Nick H. Supervisor]

OP is confused.

So why not call it a NAND rather than a ROM? I'm all for being confused, but I would like understanding to clear the fog. ;)

[SionicIon]

Yea I know it is read-only memory supposedly, I read that around the web. But what I mean is growing up with Windows, Ubuntu, OSX, the file managers and disk tools always pointed to partitions, the BIOS chip or UEFI chip boots one of the drives, starting with the first code it sees, the MBR or GPT, this helps it find the bootloader, unless it is UEFI then it can usually directly boot the kernel, this brought you to your operating system, your files were in folders somewhere on the same system partition.

 

Now lets bring it back to modern mobile OSs, all these files still exist but they are read-only. I've only encountered Windows RT to actually show you an ARM variant of Windows, with everything still the way it was on a regular PC, but all on a ARM SOC. As far as Android phones go, you flash whatever ROM you desire, you don't have to repartition, then format the right filesystem, execute the installer and then at the end adds itself to the bootloader, and then restart your PC ahem I mean phone. Instead you just flash what would basically be a HDD clone on a PC using some disaster recovery utility, and it restores it to whatever the state of the ROM is at. And consider, the ROM is read-only, unlike our partitions on PCs where you can change system files.

 

Does this make sense as to what I mean to convey? Why do we have ROMs all across Android, for restoring to stock, to going cyanogenmod, or etc. And I'm sure this all applies elsewhere too, iOS is an image you flash, so is WP8. I have yet to see an actual install for a phone's OS to a phone.

[vcfan]

the term ROM is used to refer to the OS partition that resides in an area of storage that the user usually cannot(or shouldnt) be able to modify, hence "read only memory". usually, the system sets up another partition for the user, and this is where the apps,user documents and settings get stored. when you do a factory restore, this user partition gets wiped, but the OS partition stays. this is why we dont have to re-install an OS,because its always there.

[adrynalyne]

So why not call it a NAND rather than a ROM? I'm all for being confused, but I would like understanding to clear the fog. ;)

Because NAND is a type of flash media.

 

We don't write flash media to flash media, right?

 

ROM was never  a correct term anyway, even with emulators.

[adrynalyne]

Yea I know it is read-only memory supposedly, I read that around the web. But what I mean is growing up with Windows, Ubuntu, OSX, the file managers and disk tools always pointed to partitions, the BIOS chip or UEFI chip boots one of the drives, starting with the first code it sees, the MBR or GPT, this helps it find the bootloader, unless it is UEFI then it can usually directly boot the kernel, this brought you to your operating system, your files were in folders somewhere on the same system partition.

 

Now lets bring it back to modern mobile OSs, all these files still exist but they are read-only. I've only encountered Windows RT to actually show you an ARM variant of Windows, with everything still the way it was on a regular PC, but all on a ARM SOC. As far as Android phones go, you flash whatever ROM you desire, you don't have to repartition, then format the right filesystem, execute the installer and then at the end adds itself to the bootloader, and then restart your PC ahem I mean phone. Instead you just flash what would basically be a HDD clone on a PC using some disaster recovery utility, and it restores it to whatever the state of the ROM is at. And consider, the ROM is read-only, unlike our partitions on PCs where you can change system files.

 

Does this make sense as to what I mean to convey? Why do we have ROMs all across Android, for restoring to stock, to going cyanogenmod, or etc. And I'm sure this all applies elsewhere too, iOS is an image you flash, so is WP8. I have yet to see an actual install for a phone's OS to a phone.

It is that way because people are stupid and would destroy their devices.

 

Not to mention that NAND is better suited for phones than an SSD, which would be overkill.  You mostly read, and do a bit of writing.  An SSD would be a waste.

[Gotenks98]

XDA developers is your friend. If you don't use the default firmware of the phone then its closer to what a PC does. In some cases you can change the partitioning structure of a phone and even dual boot as well.

[mrp04]

SSDs contain multiple NAND chips. Phones use eMMC which are single NAND chips. Mostly the same thing.

 

ROM is just an outdated and somewhat incorrect term. For the MOST part the system partition on most phones is usually read-only, until you are installing an update. Then the system writes to it but the user never gets write access to it (unless if you have a "rooted" or "jailbroken" phone then you can write to the system partition with no issue.) This is both a holdover from the old days and also a security/ease of use feature. When the user factory resets the phone the phone simply wipes the user data partition and boots up. It doesn't allow users to mess it up.

 

There's no technical reason that phones aren't partitioned and set up the same way as traditional computers. It's just a matter of choice. As you said Windows RT does expose the storage to the user. The same partition holds the Windows OS and the user data. This has a downside: to allow the user to factory reset the device there is another partition that contains a factory image that gets copied to the main partition. This wastes a significant amount of space (~7GB) on computers with just 16-64GB storage. Windows does let the user move it to a flash drive to free up space on the internal storage though.