[J-core] working on SH-2 emulator.

[BGB]

On 9/6/2016 2:26 AM, D. Jeff Dionne wrote:
> The driver does exist...  here is a print of my boot just a few min ago:
>
> Open vmlinux OK
> Use bootloader's DTB
> RUN program
> Linux version 4.6.0-00044-g127f81a-dirty (jeff at VirtualSuSE) (gcc version 5.3.0 (GCC) ) #2 SMP Sun Sep 4 07:28:34 EDT 2016
> Boot params:
> ... MOUNT_ROOT_RDONLY - 00000001
> ... RAMDISK_FLAGS     - 00000000
> ... ORIG_ROOT_DEV     - 00000200
> ... LOADER_TYPE       - 00000001
> ... INITRD_START      - 00000000
> ... INITRD_SIZE       - 00000000
> earlycon: uartlite_a0 at MMIO 0xabcd0100 (options '')
> bootconsole [uartlite_a0] enabled
> Booting machvec: devicetree
>
> The relevant lines in .config are:
>
> #
> # Serial drivers
> #
> CONFIG_SERIAL_EARLYCON=y
> # CONFIG_SERIAL_8250 is not set
>
> #
> # Non-8250 serial port support
> #
> # CONFIG_SERIAL_MAX3100 is not set
> # CONFIG_SERIAL_MAX310X is not set
> CONFIG_SERIAL_UARTLITE=y
> CONFIG_SERIAL_UARTLITE_CONSOLE=y
> # CONFIG_SERIAL_SH_SCI is not set
> CONFIG_SERIAL_CORE=y
> CONFIG_SERIAL_CORE_CONSOLE=y

good to know. I am working on getting the kernel rebuilt (ex: trying to 
use Aboriginal).
this is pretty slow and it didn't work the first attempt, so trying again.
if it doesn't work, I might try "sh2elf" rather than "sh2eb".

as noted, I did add CAS, SHAD, and SHLD, since in this case there wasn't 
really all that much reason not to.


"sh2elf" gets a little further than "sh2eb", but both die due to errors.
may mess with it more later, for now needing to sleep...


>
>> On Sep 6, 2016, at 4:04 PM, Rob Landley <rob at landley.net> wrote:
>>
>> On 09/06/2016 12:53 AM, D. Jeff Dionne wrote:
>>> On Sep 6, 2016, at 2:46 PM, BGB <cr88192 at gmail.com> wrote:
>>>
>>> Oh, excellent.  This means you have passed all the CPU tests, and dropped into
>>> a GDB stub.  Did you implement and test the J2 CAS instruction, or
>> patch it out?
>>
>> CAS an the two bit-shifts from sh3. (All mentioned on http://j-core.org
>> but I really should have better docs.)
>>
>> Alas, our arch/sh/configs/j2_defconfig does not appear to have
>> EARLY_PRINTK set, most likely because we haven't got an early printk
>> driver for our serial device. So you've got to get pretty far along in
>> the kernel boot before it dumps the printk buffer out to the serial device.
>>
>> (I remember Rich poking at that area before, but I don't remember how it
>> turned out. Possibly it's just not enabled in the config?)
>>
>> Rob