ROM vs SSD (Smartphone VS PC)

>>58664415
Are you actually retarded?

>>58664415
Smartphoes use eMMC DRAM.

>>58664436
This

>>58664415
It is actually EEPROM, Electronically programmable read-only memory, so basically it is a hack to make ROM rewritable.

>>58664481
>A hack

>>58664415
They both use flash nand.......

>>58664415
>If it was a read/write memory would be a lot better for users who want to install extra OS or even look into the phone internals
>users
>install extra OS or even look into the phone internals
Let me introduce you to a little thing called capitalism

>>58665317
>>>/cccp/

>>58664481
>so basically it is a hack to make ROM rewritable
False. It's a hack to protect DRAM from being written to.

>>58664415
Can be ban people for being retarded?

>>58664481
Didn't know they used an EPROM, now that explains why we can rewrite it and add a new firmware, although the process is not even close to what is usual in computers, you can't add layers of software like grub and etc.. because you have to write it all in the same memory once. That's why I posted this question, to try to understand why would this be an advantage. However someone already replied what I think must be the ansewr, "capitalism".

>>58665722
maybe if you stop being retarded and actually say something

>>58665821
Fast question: do you even speak english?

>you can't add layers of software like grub
You can, no, it has been done in the past for some phones with multiple roms

>because you have to write it all in the same memory once
?

The underlying tech between the phone memory and the solid state drive are the same.
Everything possible for one can be done with the other.


>EPROM
It's EEPROM. Learn the difference.

>>58664981
your storage is flash, however your "BIOS" and "bootmanager", in android devices, the so called bootloader as also the backup android firmware, that is all stored in a EPROM (actually that's why we call it firmware)

>>58665894
sorry man, but the tech part is wrong, the main concepts are shared by all memories, but for some reason you use ROM type memories (as EEPROM), to store firmware, because the read/write process is not equivalent

>>58664415
they don't use actual mask ROM, it called ROM just because it's only read in normal operation, it's actually on flash EEPROM like the rest of your phones' storage

about the grub, look, you must install gub from a linux distro, usually you do it pos distro installation in the system, if the memory doesn't allow to write in stages, then all the software including grub must be written once (the process is not smiliar at all)

>>58666056
but you can install linux in the usual way or am I wrong?

>>58665821
don't confuse EEPROM with EPROM

ops' pic shows an EPROM, it is writable, but can only be erased by exposing it to strong UV light, hence the window
EEPROM is electronically writable (programmable) AND erasable

*can't

>>58666091
what do you mean? usual way for a phone? if you couldn't, how would you update it officially or with custom roms? ("roms" in this context meaning rom image files)
usual way for a PC? no, phones aren't PC's

>>58665989
Man, i hope you're not some sort of pajeet

Every firmware (The BIOS) is stored in a ROM of sorts.
Old machines use socketed PROMs, while new machines are EEPROM.

Now, no software normally writes inside the BIOS area, so every customization is made inside the user-reserved space (Mass memories like HDDs, WORM and RW CD/DVDs, floppy disks if you're that type of guy, flash chips.

After you pass POST, the CPU jumps to the first master device of the first partition of the first device of the first channel of the first bus, with computers it's the First Master IDE device / First sata bus / First available device. After the CPU finds out the first device location, full power is given to the first cylinder/sector/block of the device, which contains the bootloader.

The bootloader, because of it's position, can be modified.

So you can modify everything that's not the BIOS.

>>58666130
first, I want to understand something, when you write a ROM (like cyanogenmod) into the phone memory, you overwrite all the ROM memory or are you able to edit just some few blocks?

>>58666190
in most cases, the flash rom in your phone is one space, partitioned off to separate the system firmware, recovery firmware, user data, and perhaps others
it's flash-based, so it's erased/programmed in blocks

ever wonder why say, an "8G" phone has like, 7G available to you? the first 1G is part of partitions that aren't for user data

>>58666190
The part that prevents you from writing to the OS partition on phones is purely software and has got nothing to do with hardware based protection such as Read Only Memory.

It's pseudo-ROM, and i say that because it can be rewritten and changed if you have root level access on the OS. However, the OS puts up restrictions to prevent you from doing just that by having you run everything as an unprivileged user.

The only true ROM you find in a cellphone would be the firmware for the baseband processors.

>>58666261
so, why are ROMs specifically build for a certain device? In a regular computer (I say regular because Smartphones are also computers, they have, at least, all the components of such device), you just need to get an image specific for your architecture and all the software needed to control your display (for example) can be added later.

*processor architecture

>>58666381
Different chipsets.
You can't waste 9e+99 gigabytes of data with drivers not even usable on the system.
Also, retarded propietary BIOS functons, buttons and controllers.

>>58666381
proprietary drivers, which are only available for specific versions of the linux kernel
that and there's no standard for the way phones are made, and detecting hardware isn't done the same way across various SoCs, which also complicates making a rom that can function on multiple devices

>>58666426
>You can't waste 9e+99 gigabytes of data with drivers not even usable on the system.
this isn't a problem, you think your desktop linux distro only installs drivers for your specific hardware?
most drivers are small, and modern phones have tons of space

>>58666476
>you think your desktop linux distro only installs drivers for your specific hardware?
No, i think that my linux distro installs generic drivers that are COMPATIBLE with my device.
With phones, most of the time, you have NO compatibility

>>58666496
"generic" drivers only apply to certain kinds of hardware, that is, ones that conform to some kind of generic interface
for example, usb flash drives can all be communicated with using the same driver, as they all use same USB Mass Storage standard, the driver only needs to implement that

ok, I get it know.
>>58666426
but you can connect to the internet and download just the drivers you need
>>58666446
with so many standarts out there, companies shouldn't build things so independently that feels like a regression needing to adapt to a single device

File: 1458810916343.png (131KB, 434x460px) Image search: [Google]

131KB, 434x460px

>>58664415

>>58665961
No, not with every SoC. That's why hard-bricking is a thing

>>58666547
>with so many standarts out there, companies shouldn't build things so independently that feels like a regression needing to adapt to a single device
unfortunately, most phones are made to be disposable, they make them with the expectation that they will be used for a while, maybe updated once or twice with official roms by the manufacturer, then thrown away

hopefully at some point someone tries to make a standard for phone hardware

PCs became a standard because it was about the only way for machines made by different manufacturers to be able to easily run the same operating system, and therefore the same software
since manufacturers are able to modify android to suit their hardware, they're not forced to make their hardware conform to any standards

>>58666547
>Implying smartphone developers give out internal drivers
>Implying you can access the phone without the right usb client drivers
>Implying you can interact with the phone without any I/O drivers

Well, thanks, I learned what I came here to learn. So, seems that I'll need to wait for some standarts in the smartphone world or read the fucking manuals and create my own ROMs.

It's usually eMMC NAND Flash, usually TLC.

The structure is very different to EEPROM, which is much bigger and older and, unlike NAND, can be securely zeroised.

The SoCs generally also contain a certain amount of onboard NOR Flash for microcode and first-stage bootloaders.

It is comparatively rare for mobile phone-targeted SoCs to contain EEPROM of any form, even for storage of cryptographic keys (the one area EEPROM still shines). Apple's most recent Secure Enclave coprocessor does.

It is also common for SoCs to contain an area of a particular form of write-once PROM known as fuse bits - once a 1 bit is written to this structure, it stays written permanently (unless reset by extremely close physical intervention). These are used for things like bootloader management and security, chipset codec and feature licensing and in some cases unlock and warranty status.

Your OP pic contains an EPROM, which is erased by applying ultra-violet light to the core which is visible under the window in the package - these have not been in any common use since the 80s because they are much more delicate than EEPROM.

>>58664415
>Why do our smartphones use ROM instead of an SSD of smiliar memory?
What the hell are you saying?

>>58666261
I don't think I've ever seen a modern phone baseband with operational firmware in ROM. They seem to consider that a waste of die space.

Usually the bootloader needs to feed it a firmware blob (which is almost always signed and in many cases obfuscated/encrypted) - Android, for example, uses one of several "radio" partitions for this purpose, but it depends on the hardware of course, as for example Qualcomm SoCs have the baseband on the same chip.

If this reminds you of WinModems - it should. They basically are.