[Arm-netbook] RK3399

Christopher Havel laserhawk64 at gmail.com
Fri Jan 19 02:57:03 GMT 2018


Forgive a top-post, please, Luke - I'm on my phone.

Coreboot, IIRC, is a replacement for BIOS/UEFI. So if you have the original
system's motherboard intact - in which case you cannot drop in the chip you
want to drop in - you can replace the contents of what is essentially the
boot ROM chip with coreboot. That's as far as that goes...

In case you do not understand what BIOS and UEFI are, read on...

When a computer is first turned on, the CPU automatically copies the
contents of the BIOS (or UEFI) into RAM, which is called 'shadowing' the
ROM. It then jumps to a specific address, hard-coded into the CPU, to start
execution of part of those instructions.

For the record, historical processors typically started either at 0x0000,
assuming a 16b address bus, or at 0xFFFF. The 8086 and 8088 did something
different, and I forget now what that address was, but it was in the middle
somewhere, IIRC.

*ahem*

The code executed at boot is enough to test how much RAM is present and
functional, and to bring up various parts and pieces of the system so that
it can function cohesively and coherently. Hard drive interfaces and
accessing. Some sort of display function for output. Keyboard and mouse
interfaces. *Et cetera*.

Once this is complete, and a limited 'sanity test' (POST, the Power On Self
Test) is executed, the BIOS (UEFI) code loads the OS bootloader into RAM
and begins executing that - whether it's GRUB or NTLDR, that is the part
where the OS begins to take over. The bootloader pulls up the kernel and
whatever init program is present, and away you go.

...all that to say that coreboot basically can't help you here, because all
of that is what coreboot duplicates, and that's *all* it does.

Sorry for the long yarn of explication, but I wanted to be thorough. My
hand hurts now, though, so "here endeth the lesson", as my mother often
says :)

On Jan 18, 2018 9:35 PM, "Bill Kontos" <vkontogpls at gmail.com> wrote:

> On Thu, Jan 18, 2018 at 6:58 PM, Luke Kenneth Casson Leighton
> <lkcl at lkcl.net> wrote:
>
> >  no.
> >
> >  it is a vast amount of work.  the LCD has to be researched (if its
> > datasheet is even available).  a conversion circuit has to be designed
> > and manufactuered.... and before that it is necesssary to work out if
> > there is room for it.
> >
> >  the keyboard hsa to be reverse-engineered
> >
> >  the trackpad has to be reverse-engineered
> >
> >  the connectors have to be researched (heights, sizes), PCB heights
> > measured.... or you have to cut holes in the casework to get the PCB
> > to fit.
> >
> >  the battery has to be researched and reverse-engineered, paying
> > attention to safety as you could set fire to it if you get it wrong.
> >
>
> What if the laptop in question has coreboot support?
>
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