xserver - black screen

[starikarp at yandex.com]

Hi!

I replaced hard drive on my iMac 11,1 (late 2009) and I didn't install
OS X but I installed FreeBSD 12.0-RELEASE (amd64) with success and it
works. For the partitioning of the new SSD drive I use "auto".
And now I have:
gpart show
=>       40  976773088  ada0  GPT  (466G)
         40     409600     1  efi  (200M)
     409640  968474624     2  freebsd-ufs  (462G)
  968884264    7888864     3  freebsd-swap  (3.8G)

and 


 gpartlist 
Geom name:
 ada0 modified:
 false state:
 OK fwheads:
 16 fwsectors:
 63 last: 976773127
first: 40
entries: 152
scheme: GPT
Providers:
1. Name: ada0p1
   Mediasize: 209715200 (200M)
   Sectorsize: 512
   Stripesize: 0
   Stripeoffset: 20480
   Mode: r0w0e0
   efimedia: HD(1,GPT,e86f27af-021d-11e9-bb45-0023dffff19f,0x28,0x64000)
   rawuuid: e86f27af-021d-11e9-bb45-0023dffff19f
   rawtype: c12a7328-f81f-11d2-ba4b-00a0c93ec93b
   label: (null)
   length: 209715200
   offset: 20480
   type: efi
   index: 1
   end: 409639
   start: 40
2. Name: ada0p2
   Mediasize: 495859007488 (462G)
   Sectorsize: 512
   Stripesize: 0
   Stripeoffset: 209735680
   Mode: r1w1e1
   efimedia:
 HD(2,GPT,e86fcbc6-021d-11e9-bb45-0023dffff19f,0x64028,0x39b9c000)
 rawuuid: e86fcbc6-021d-11e9-bb45-0023dffff19f rawtype:
 516e7cb6-6ecf-11d6-8ff8-00022d09712b label: (null)
   length: 495859007488
   offset: 209735680
   type: freebsd-ufs
   index: 2
   end: 968884263
   start: 409640
3. Name: ada0p3
   Mediasize: 4039098368 (3.8G)
   Sectorsize: 512
   Stripesize: 0
   Stripeoffset: 2147504128
   Mode: r1w1e1
   efimedia:
 HD(3,GPT,e870c5df-021d-11e9-bb45-0023dffff19f,0x39c00028,0x785fe0)
 rawuuid: e870c5df-021d-11e9-bb45-0023dffff19f rawtype:
 516e7cb5-6ecf-11d6-8ff8-00022d09712b label: (null)
   length: 4039098368
   offset: 496068743168
   type: freebsd-swap
   index: 3
   end: 976773127
   start: 968884264
Consumers:
1. Name: ada0
   Mediasize: 500107862016 (466G)
   Sectorsize: 512
   Mode: r2w2e4

I did install Xorg, Openbox and some other apps which I had before and
also drm-kmod which choose version for 12 and xf86-video-ati.
But after startx it start just black screen. I also try drm-legacy-kmod
and legacy ati drivers but it is the same black screen.

sysctl machdep boothmetod shows UEFI

and 
sysctl kern.vty shows vt

I also try to make xorg.conf but I got the black screen too.
I made in /usr/local/etc/X11/xorg.conf.d/driver-scfb.conf and it works.

Any suggestion how should I use mine Radeon 4850, please?

Thank you.

P.S.

Please check attached logs.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: xorg.conf.new
Type: application/octet-stream
Size: 2673 bytes
Desc: not available
URL: <http://lists.freebsd.org/pipermail/freebsd-x11/attachments/20181221/76426108/attachment.obj>