Dreamcast Build for NetBSD + Dreamshell

SCIMMC SDCard Port

SCIMMC SDCard Port Internal

BIOS Mod (stock atm)

G1ATA + Blue/Teal HDD Activity led (dreamcast power led / RGB 4 pin led)

Overview

STD DC Serial Port to USB Trans

USB Console of NetBSD

Spoiler: Original NetBSD mailing list

http://mail-index.netbsd.org/port-dreamcast/2014/10/30/msg000265.html
SCIMMC PINOUT:
SCLK = R140
DI = R122
DO = R115
CDET = R159
CS = R121

NOTE: You do not need the blue wire in the picture, its next to the green R140, so R128 is not needed.

Front locations

Running NetBSD 6.0 w/ modified scimmc control driver (8bit bus width, original source bus clock, no dma)
Boot Sequence:
1: GDROM > Dreamshell stage1 boot-loader
2: Dreamshell over G1ATA > File Manager
3: Launch Selected NetBSD kernel.
Kern with pvr0 console
Kern with scif0 console

It loads relatively quick and is stable. Im using my own compilation of NetBSD 6.0 for Dreamcast.

I also have started working on my own "DCEXT" board for ISA only (NE2000 based ISA Ethernet controller)

 

Man that is wicked!

 

Translation. What doors are we seeing opened with your project? It looks awesome but also some what complex. Why does every hdd mod I see is ide and not Sata?

 

Ide is very similar to the internal protocol used for the gdrom (it's a modified ide really).

Sata seems easier for the end user, but it's also relatively modern and heavy for an older system like the dreamcast.

BTW nice job! Does it run python?

 

lua works XD

the sci bus the mmc driver uses is clocked down by 1000 so 50mhz is something i would think to be possible but not really ideal. i could be wrong on the bus info tho

 

Update:
Fixed rootfs rw issues.
Configured rc.conf and rc.local
New optimized "again" kernel sets
Custom shell script to invoke reboot into specific console mode (sio or pvr)

i think ill make a quick video.

 

Would it be possible to run a minimal shell from the serial sd-card? Without using the HDD? I'd sure have fun messing with my dc, maybe add python support , but I don't want to manually add a HDD to it as I have no other uses for that.

 

yep just build a selfboot netbsd kernel only disk and away u go ^^.
dl bootdreams,
use the tab for "CDRecord"
leave everything alone and just locate you directory with the "netbsd.bin" in it. thats the only thing required as bootdreams with generate the ip.bin and all that jazz.
then click burn disk or w/e in bootdreams and there u go ^^.

MAKE sure if u dont have a DC keyboard to edit the kernel configuration file to enable SCIFCONSOLE by un commenting the #. works with any Tx + Rx serial device on your pc, u only need rx n tx atm for serial console for *bsd.

 

Any link to the binaries/source needed? I can selfboot fine (that's my specialization here), but idk much about BSD for Dreamcast (although I know linux, which is similar being both unix).

Thanks!

 

i got one ready to burn as selfboot
https://www.dropbox.com/s/ky8adrktmm0pdi7/netbsd-serial-console_v21.bin?dl=0
its for serial console only i can make a pvr updated one in a bit. install the mod first and by then ill have pkg'ed my os in a tar bundle with some instructions for making the rootfs bootable (needs netbsd vm on ur pc). then u can burn and test. either pvr or sio.

 

Thanks!
If I understand correctly, this will give me access to a terminal over serial? So using a coder's cable I could access the BSD system running on the DC? I'll have to make myself a coder's cable then

 

well yes thats correct for the sio version. its just like ssh but over you pc serial to the dreamcast.
the pvr version uses the dreamcast as console and display host, u will need a dc keyboard and even better would be if u had a LAN or BBA adapter to use networking.
almost done taring the rootfs, then to make a few kernels for users to test.

 

having some issues with the rootfs. its refusing to mount rw access due to the missing character | device files under /dev for the sdcard on ld0.
i cant seem to create ones that match what the dreamcast is defining the sdcard as.

working on this atm, got the rc.conf to include updating the dev dir at startup, didnt make a diff due to prior mount as ro.

i haven't messed with bsd in while till now ^^. lol

 

dvd drives on the g1ata mod ^^

 

Cool

 

I got SWAT on board to implement this SCIMCI driver into the next Dreamshell Release. Supports DMA and scale-able bus speed / control.
guna be sweet.

Update: heres some kernels
https://www.dropbox.com/s/75kqq8kb6..._MMC-NetBSD-6.0-scif0-pvr0-multipack.rar?dl=0