Re: GPLv3 Position Statement

I generally agree with you, but...

Linus Torvalds <torvalds@xxxxxxxx> writes:

And it not at all uncommon to have a flash that simply cannot be upgraded
without opening the box. Even a lot of PC's have that: a lot (most?) PC's
have a flash that has a separate _hardware_ pin that says that it is
(possibly just partially) read-only. So in order to upgrade it, you'd
literally need to open the case up, set a jumper, and _then_ run the
program to reflash it.

I think this is history. Yes, late 486s and Pentiums (60 and 66?)
had a jumper protecting the flash. It's not true since ca. "Pentium 75+"
days - while many boards use "bootblock" chips, it's (almost?) always
unprotected (at most it just requires setting some GPIO pin(s)). The
rest of flash obviously has to be R/W to support the ESCD etc.

I think there are systems with 2 copies of the whole BIOS, and the
user selects the copy with a jumper (probably connected directly to
the most significant address line of the flash IC) - the second
copy might theoretically use a R/O bootblock but I've never checked it.

Most VGAs, disks, PCI cards etc. have flash chips with no protection
either, and I have to say I felt much better when they used (EP)ROMs.

I think almost all hardware manufacturers use a blank flash chips,
programming them "in system" with things like JTAG.
--
Krzysztof Halasa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Relevant Pages

  • Re: Ultra 1 wont boot
    ... > has never been OBP updated, so I would like to hear more about this: ... if you install Solaris I think the installer will update the ... manually and also move a jumper on the board before updating the flash, ... en after updated put the jumper back to Read-only mode. ...
    (comp.unix.solaris)
  • Re: Problem with the pci.sys driver on Vista
    ... In the process of disassembling things to place that jumper perhaps you ... Power down and let things sit, with power cable NOT plugged into wall power ... for my Elite RX480-A motherboard. ... flash fails because I had to set a jumper beforehand on the motherboard. ...
    (microsoft.public.windowsxp.device_driver.dev)
  • Cisco PIX506 Flash upgrade
    ... Has anybody succesfully upgrade a PIX506 from the native 8MB Flash to ... The Main Board has a single Intel 8MB Strata Flash chip soldered in ... empty chip pad next to the existing flash chip. ... added or a jumper pad that needs to be bridged or cut. ...
    (comp.dcom.sys.cisco)
  • Re: Boot ROM corruption
    ... Pretty unlikely a random series of writes to flash could cause a sector ... We are facing a peculiar problem with the boot rom getting corrupted on ... if your 'rom' is indeed flash memory, there is often a jumper to ... Once the boot code is ...
    (comp.os.vxworks)
  • RE: IPSM w/ P30 Flash Results in Registry Corruption
    ... P30 parts not getting completely flushed to the flash chip. ... the flash chips, but otherwise, until CE 5.0, these isn't anyway to get the ... The result is we have one application bank and one boot bank of ... The upper bank is used to store the windows registry and a user file ...
    (microsoft.public.windowsce.platbuilder)