What is the differences between booting from "ram" "rom" and "disk"?

[xman099]

I followed the “iriver flashing”, and then, I can find  "boot ram image" "boot rom image" and "boot from disk" in boot menu.

I just know that it use the place which stored original firmware before to create "ram" and "rom" image. However, I really can't understand what the meaning of them. Is there any differences?

Thanks a lot.

[AlexP]

Boot from ROM - the build is stored in ROM and executed from ROM
Boot from RAM - the build is stored in ROM, but then copied to RAM and executed
Boot from Disk - the build is stored on Disk, then copied to RAM and executed

Executing from RAM uses additional memory that could otherwise be used for buffering audio if the build was executed from ROM, but is quicker.  Copying from ROM is quicker than copying from disk.

All as I understand it

[xman099]

Thanks AlexP.

So, both of the "Boot from ROM" and "Boot from RAM" use the ROM image(0x001000 - 0x0EFFFF), what is RAM image(0x100000 - 0x1EFFFF) used for?

And, could I do the same thing(iriver flashing) on H3X0?

[AlexP]

The H300 doesn't support this at this point, no.

As I understand it, the ROM image is the one stored in ROM and executed from ROM, and the RAM image is the one stored in ROM and executed from RAM.

[torne]

The RAM/ROM images are different because they are built to run from different places. It doesn't matter where they are stored, it only matters where they are going to actually run from in the end: anything that gets loaded to RAM to run it must be a RAM image, anything run directly from ROM must be a ROM image.

[xman099]

Thank both of you!  I understand that FANLLY

[pondlife]

If anyone is tempted to play with the H300 bootloader from SVN, they should know that it will currently brick your H300 (permanently, unless you have access to BDM kit and know how to use it).

The released (v5) bootloader is fine, I'm referring to the bleeding-edge SVN code.

pondlife