legacy ATI Radeon Xorg and KMS driver support to trident_init

[jgroenveld]

Not sure if you're looking to add legacy (2012) AMD support to trident_init, but below works for me.
John
groenveld@acm.org

# dmidecode | grep -A2 "System Information"
System Information
        Manufacturer: Dell Inc.
        Product Name: OptiPlex 790

# pkg which /usr/local/lib/xorg/modules/drivers/radeon_drv.so
/usr/local/lib/xorg/modules/drivers/radeon_drv.so was installed by package xf86-video-ati-18.1.0,1

#  diff -c trident_init.trident trident_init
*** trident_init.trident        Tue Mar  5 18:01:06 2019
--- trident_init        Tue Mar  5 17:30:22 2019
***************
*** 27,32 ****
--- 27,35 ----
                        kld_load="nvidia"
                fi
                ;;
+       radeon)
+               kld_load="radeonkms"
+               ;;
        amdgpu)
                kld_load="amdgpu"
    esac

# cat /etc/X11/xorg.conf:
Section "ServerLayout"
        Identifier     "XFree86 Configured"
        Screen      0  "Screen0" 0 0
EndSection

Section "Screen"
        Identifier "Screen0"
        Device     "Card0"
        Monitor    "Monitor0"
EndSection

Section "Device"
  Identifier      "Card0"
  Driver          "radeon"
EndSection

# about
Project Trident Information
--------------------------------------
OS Version: 18.12-RELEASE-U6
Build Date: 20190221202700
--------------------------------------
TrueOS Sources Used:
  Base Repository: https://github.com/trueos/trueos
  Base Commit Branch or Tag: trueos-stable-18.12
  Ports Repository: https://github.com/trueos/trueos-ports
  Ports Commit Branch or Tag: d08d5280813e403ab9fbdc82de43b5fa9788b4b9
--------------------------------------
System Specs:
  Boot Method: BIOS
  Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz
  Physical CPUs: 4
  Physical Memory: 7.91 GB
--------------------------------------
GPU Information:
  vgapci0@pci0:1:0:0:   class=0x030000 card=0x21201028 chip=0x67791002 rev=0x00 hdr=0x00
    vendor     = 'Advanced Micro Devices, Inc. [AMD/ATI]'
    device     = 'Caicos [Radeon HD 6450/7450/8450 / R5 230 OEM]'
    class      = display
    subclass   = VGA
--------------------------------------
Network Device Information
  em0@pci0:0:25:0:      class=0x020000 card=0x047e1028 chip=0x15028086 rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = '82579LM Gigabit Network Connection (Lewisville)'
    class      = network
    subclass   = ethernet

[beanpole135]

Done!
This change will be included in 18.12-U7