ok so far i got it managed to get my screen working. 
in my kernel .config i have these settings for radeon / drm
Device Drivers  --->
    Graphics support  ---> 
        <*/M> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) --->
        <*/M> ATI Radeon
        [*] Enable modesetting on radeon by default
        -*- Support for frame buffer devices  --->
            < >   ATI Radeon display support
Device Drivers  --->
    Generic Driver Options  --->
        [*] Include in-kernel firmware blobs in kernel binary
            (radeon/... radeon/...)
            (/lib/firmware) Firmware blobs root directory
cat .config | grep FIRMWARE
CONFIG_PREVENT_FIRMWARE_BUILD=y
CONFIG_FIRMWARE_IN_KERNEL=y
CONFIG_EXTRA_FIRMWARE="radeon/kabini_ce.bin radeon/kabini_me.bin radeon/kabini_mec.bin radeon/kabini_pfp.bin radeon/kabini_rlc.bin radeon/kabini_sdma.bin radeon/BONAIRE_uvd.bin radeon/BONAIRE_vce.bin"
CONFIG_EXTRA_FIRMWARE_DIR="/usr/local/lib/firmware"
# CONFIG_DRM_LOAD_EDID_FIRMWARE is not set
CONFIG_FIRMWARE_EDID=y
CONFIG_FIRMWARE_MEMMAP=y
# CONFIG_GOOGLE_FIRMWARE is not set
# CONFIG_TEST_FIRMWARE is not set
now dmesg looks like this:
dmesg | grep -E 'amd|drm|radeon'
[    8.802579] bus: 'pci': add driver pata_amd
[   14.528163] device class 'drm': registering
[   14.994894] device class 'drm_dp_aux_dev': registering
[   15.468889] [drm] amdgpu kernel modesetting enabled.
[   15.654384] bus: 'pci': add driver amdgpu
[   15.654401] bus: 'pci': driver_probe_device: matched device 0000:00:01.0 with driver amdgpu
[   15.654408] bus: 'pci': really_probe: probing driver amdgpu with device 0000:00:01.0
[   15.654418] amdgpu 0000:00:01.0: no default pinctrl state
[   16.286527] [drm] initializing kernel modesetting (KABINI 0x1002:0x9833 0x1734:0x1202 0x00).
[   16.286591] [drm] register mmio base: 0xFEB00000
[   16.286593] [drm] register mmio size: 262144
[   16.362782] [drm] BIOS signature incorrect 76 7
[   16.373465] [drm] GPU post is not needed
[   16.375513] [drm] vm size is 64 GB, block size is 13-bit, fragment size is 4-bit
[   16.375528] amdgpu 0000:00:01.0: VRAM: 32M 0x0000000F00000000 - 0x0000000F01FFFFFF (32M used)
[   16.375531] amdgpu 0000:00:01.0: GTT: 1024M 0x0000000F02000000 - 0x0000000F41FFFFFF
[   16.375542] [drm] Detected VRAM RAM=32M, BAR=32M
[   16.375543] [drm] RAM width 64bits UNKNOWN
[   16.380147] [drm] amdgpu: 32M of VRAM memory ready
[   16.380150] [drm] amdgpu: 3072M of GTT memory ready.
[   16.380169] [drm] GART: num cpu pages 262144, num gpu pages 262144
[   16.380808] [drm] PCIE GART of 1024M enabled (table at 0x0000000F00040000).
[   16.380951] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[   16.380953] [drm] Driver supports precise vblank timestamp query.
[   16.381087] amdgpu 0000:00:01.0: amdgpu: using MSI.
[   16.381146] [drm] amdgpu: irq initialized.
[   16.381156] [drm] Internal thermal controller without fan control
[   16.381160] [drm] amdgpu: dpm initialized
[   16.381503] device: 'drm_dp_aux0': device_add
[   16.381527] PM: Adding info for No Bus:drm_dp_aux0
[   16.382089] [drm] AMDGPU Display Connectors
[   16.382090] [drm] Connector 0:
[   16.382091] [drm]   DP-1
[   16.382092] [drm]   HPD1
[   16.382095] [drm]   DDC: 0x194c 0x194c 0x194d 0x194d 0x194e 0x194e 0x194f 0x194f
[   16.382096] [drm]   Encoders:
[   16.382097] [drm]     DFP1: INTERNAL_UNIPHY
[   16.382098] [drm] Connector 1:
[   16.382099] [drm]   DVI-I-1
[   16.382100] [drm]   HPD2
[   16.382103] [drm]   DDC: 0x1950 0x1950 0x1951 0x1951 0x1952 0x1952 0x1953 0x1953
[   16.382103] [drm]   Encoders:
[   16.382104] [drm]     DFP2: INTERNAL_UNIPHY
[   16.382106] [drm]     CRT1: INTERNAL_KLDSCP_DAC1
[   16.382118] amdgpu 0000:00:01.0: using built-in radeon/kabini_pfp.bin
[   16.382123] amdgpu 0000:00:01.0: using built-in radeon/kabini_me.bin
[   16.382126] amdgpu 0000:00:01.0: using built-in radeon/kabini_ce.bin
[   16.382130] amdgpu 0000:00:01.0: using built-in radeon/kabini_mec.bin
[   16.382134] amdgpu 0000:00:01.0: using built-in radeon/kabini_rlc.bin
[   16.382421] amdgpu 0000:00:01.0: fence driver on ring 0 use gpu addr 0x0000000f02400080, cpu addr 0xffffc900006f9080
[   16.386728] amdgpu 0000:00:01.0: fence driver on ring 1 use gpu addr 0x0000000f02400100, cpu addr 0xffffc900006f9100
[   16.386843] amdgpu 0000:00:01.0: fence driver on ring 2 use gpu addr 0x0000000f02400180, cpu addr 0xffffc900006f9180
[   16.390161] amdgpu 0000:00:01.0: fence driver on ring 3 use gpu addr 0x0000000f02400200, cpu addr 0xffffc900006f9200
[   16.390281] amdgpu 0000:00:01.0: fence driver on ring 4 use gpu addr 0x0000000f02400280, cpu addr 0xffffc900006f9280
[   16.393399] amdgpu 0000:00:01.0: fence driver on ring 5 use gpu addr 0x0000000f02400300, cpu addr 0xffffc900006f9300
[   16.393517] amdgpu 0000:00:01.0: fence driver on ring 6 use gpu addr 0x0000000f02400380, cpu addr 0xffffc900006f9380
[   16.396731] amdgpu 0000:00:01.0: fence driver on ring 7 use gpu addr 0x0000000f02400400, cpu addr 0xffffc900006f9400
[   16.396847] amdgpu 0000:00:01.0: fence driver on ring 8 use gpu addr 0x0000000f02400480, cpu addr 0xffffc900006f9480
[   16.396932] amdgpu 0000:00:01.0: using built-in radeon/kabini_sdma.bin
[   16.396938] firmware_class: __allocate_fw_buf: fw-radeon/kabini_sdma1.bin buf=ffff880004597b40
[   16.396957] amdgpu 0000:00:01.0: loading /lib/firmware/updates/4.14.10-tinycore64/radeon/kabini_sdma1.bin failed with error -2
[   16.396966] amdgpu 0000:00:01.0: loading /lib/firmware/updates/radeon/kabini_sdma1.bin failed with error -2
[   16.396975] amdgpu 0000:00:01.0: loading /lib/firmware/4.14.10-tinycore64/radeon/kabini_sdma1.bin failed with error -2
[   16.397003] amdgpu 0000:00:01.0: direct-loading radeon/kabini_sdma1.bin
[   16.397009] firmware_class: fw_set_page_data: fw-radeon/kabini_sdma1.bin buf=ffff880004597b40 data=ffffc90000505000 size=4456
[   16.397093] amdgpu 0000:00:01.0: fence driver on ring 9 use gpu addr 0x0000000f02400500, cpu addr 0xffffc900006f9500
[   16.397205] amdgpu 0000:00:01.0: fence driver on ring 10 use gpu addr 0x0000000f02400580, cpu addr 0xffffc900006f9580
[   16.397255] firmware_class: __allocate_fw_buf: fw-radeon/kabini_uvd.bin buf=ffff880004597d80
[   16.397269] amdgpu 0000:00:01.0: loading /lib/firmware/updates/4.14.10-tinycore64/radeon/kabini_uvd.bin failed with error -2
[   16.397278] amdgpu 0000:00:01.0: loading /lib/firmware/updates/radeon/kabini_uvd.bin failed with error -2
[   16.397287] amdgpu 0000:00:01.0: loading /lib/firmware/4.14.10-tinycore64/radeon/kabini_uvd.bin failed with error -2
[   16.397496] amdgpu 0000:00:01.0: direct-loading radeon/kabini_uvd.bin
[   16.397502] firmware_class: fw_set_page_data: fw-radeon/kabini_uvd.bin buf=ffff880004597d80 data=ffffc90000b81000 size=232752
[   16.397504] [drm] Found UVD firmware Version: 1.64 Family ID: 9
[   16.398816] amdgpu 0000:00:01.0: fence driver on ring 11 use gpu addr 0x0000000f0028cd30, cpu addr 0xffffc90001438d30
[   16.398851] firmware_class: __allocate_fw_buf: fw-radeon/kabini_vce.bin buf=ffff8800044fff00
[   16.398865] amdgpu 0000:00:01.0: loading /lib/firmware/updates/4.14.10-tinycore64/radeon/kabini_vce.bin failed with error -2
[   16.398873] amdgpu 0000:00:01.0: loading /lib/firmware/updates/radeon/kabini_vce.bin failed with error -2
[   16.398882] amdgpu 0000:00:01.0: loading /lib/firmware/4.14.10-tinycore64/radeon/kabini_vce.bin failed with error -2
[   16.398990] amdgpu 0000:00:01.0: direct-loading radeon/kabini_vce.bin
[   16.398996] firmware_class: fw_set_page_data: fw-radeon/kabini_vce.bin buf=ffff8800044fff00 data=ffffc90000a51000 size=101072
[   16.398998] [drm] Found VCE firmware Version: 50.10 Binary ID: 2
[   16.399691] amdgpu 0000:00:01.0: fence driver on ring 12 use gpu addr 0x0000000f02400680, cpu addr 0xffffc900006f9680
[   16.399791] amdgpu 0000:00:01.0: fence driver on ring 13 use gpu addr 0x0000000f02400700, cpu addr 0xffffc900006f9700
[   16.403804] [drm] ring test on 0 succeeded in 12 usecs
[   16.417445] [drm] ring test on 1 succeeded in 2 usecs
[   16.417470] [drm] ring test on 2 succeeded in 9 usecs
[   16.417497] [drm] ring test on 3 succeeded in 11 usecs
[   16.417527] [drm] ring test on 4 succeeded in 10 usecs
[   16.417554] [drm] ring test on 5 succeeded in 11 usecs
[   16.417583] [drm] ring test on 6 succeeded in 11 usecs
[   16.417611] [drm] ring test on 7 succeeded in 9 usecs
[   16.417644] [drm] ring test on 8 succeeded in 11 usecs
[   16.417880] [drm] ring test on 9 succeeded in 4 usecs
[   16.417888] [drm] ring test on 10 succeeded in 4 usecs
[   16.436328] [drm] ring test on 11 succeeded in 0 usecs
[   16.436707] [drm] UVD initialized successfully.
[   16.561196] [drm] ring test on 12 succeeded in 5 usecs
[   16.562589] [drm] ring test on 13 succeeded in 1 usecs
[   16.562591] [drm] VCE initialized successfully.
[   16.563815] [drm] ib test on ring 0 succeeded
[   16.563864] [drm] ib test on ring 1 succeeded
[   16.563900] [drm] ib test on ring 2 succeeded
[   16.563936] [drm] ib test on ring 3 succeeded
[   16.563976] [drm] ib test on ring 4 succeeded
[   16.564015] [drm] ib test on ring 5 succeeded
[   16.564053] [drm] ib test on ring 6 succeeded
[   16.564097] [drm] ib test on ring 7 succeeded
[   16.564135] [drm] ib test on ring 8 succeeded
[   16.564175] [drm] ib test on ring 9 succeeded
[   16.564211] [drm] ib test on ring 10 succeeded
[   16.564683] [drm] ib test on ring 11 succeeded
[   16.565094] [drm] ib test on ring 12 succeeded
[   16.631260] [drm] fb mappable at 0x7D428000
[   16.631262] [drm] vram apper at 0x7D000000
[   16.631263] [drm] size 2211840
[   16.631264] [drm] fb depth is 8
[   16.631265] [drm]    pitch is 2048
[   18.493114] fbcon: amdgpudrmfb (fb0) is primary device
[   18.664944] amdgpu 0000:00:01.0: fb0: amdgpudrmfb frame buffer device
[   18.700022] amdgpu 0000:00:01.0: kfd not supported on this ASIC
[   18.709296] [drm] Initialized amdgpu 3.19.0 20150101 for 0000:00:01.0 on minor 0
[   18.721508] driver: 'amdgpu': driver_bound: bound to device '0000:00:01.0'
[   18.732724] bus: 'pci': really_probe: bound device 0000:00:01.0 to driver amdgpu
[   18.817724] [drm] radeon kernel modesetting enabled.
[   18.817762] bus: 'pci': add driver radeon
and lsmod shows this:
lsmod
Module                  Size  Used by    Tainted: G  
bridge                 86016  0 
stp                    12288  1 bridge
llc                    12288  2 bridge,stp
ipv6                  282624 19 bridge,[permanent]
squashfs               28672 47 
zstd_decompress        77824  1 squashfs
xxhash                 12288  1 zstd_decompress
loop                   20480 94 
radeon               1007616  0 
i2c_piix4              16384  0 
fujitsu_laptop         12288  0 
amdkfd                 49152  1 
amdgpu               1404928  1 
r8169                  53248  0 
video                  32768  1 fujitsu_laptop
sparse_keymap          12288  1 fujitsu_laptop
fam15h_power           12288  0 
drm_kms_helper         90112  2 radeon,amdgpu
mii                    12288  1 r8169
igb                   118784  0 
pcspkr                 12288  0 
sp5100_tco             12288  0 
k10temp                12288  0 
ttm                    57344  2 radeon,amdgpu
ptp                    16384  1 igb
xhci_pci               12288  0 
xhci_hcd               81920  1 xhci_pci
drm                   225280  5 radeon,amdgpu,drm_kms_helper,ttm
pps_core               12288  1 ptp
backlight              12288  4 radeon,fujitsu_laptop,amdgpu,video
i2c_algo_bit           12288  3 radeon,amdgpu,igb
i am not sure which driver is now used radeon or amdgpu ? or both ...
make firmware_install does not work ? so copy firmware files for the corepure64.gz "by hand" to /lib/firmware
and what do this means, from dmesg output? :
[   16.382118] amdgpu 0000:00:01.0: using built-in radeon/kabini_pfp.bin
[   16.382123] amdgpu 0000:00:01.0: using built-in radeon/kabini_me.bin
[   16.382126] amdgpu 0000:00:01.0: using built-in radeon/kabini_ce.bin
[   16.382130] amdgpu 0000:00:01.0: using built-in radeon/kabini_mec.bin
[   16.382134] amdgpu 0000:00:01.0: using built-in radeon/kabini_rlc.bin
[   16.382421] amdgpu 0000:00:01.0: fence driver on ring 0 use gpu addr 0x0000000f02400080, cpu addr 0xffffc900006f9080
[   16.386728] amdgpu 0000:00:01.0: fence driver on ring 1 use gpu addr 0x0000000f02400100, cpu addr 0xffffc900006f9100
[   16.386843] amdgpu 0000:00:01.0: fence driver on ring 2 use gpu addr 0x0000000f02400180, cpu addr 0xffffc900006f9180
[   16.390161] amdgpu 0000:00:01.0: fence driver on ring 3 use gpu addr 0x0000000f02400200, cpu addr 0xffffc900006f9200
[   16.390281] amdgpu 0000:00:01.0: fence driver on ring 4 use gpu addr 0x0000000f02400280, cpu addr 0xffffc900006f9280
[   16.393399] amdgpu 0000:00:01.0: fence driver on ring 5 use gpu addr 0x0000000f02400300, cpu addr 0xffffc900006f9300
[   16.393517] amdgpu 0000:00:01.0: fence driver on ring 6 use gpu addr 0x0000000f02400380, cpu addr 0xffffc900006f9380
[   16.396731] amdgpu 0000:00:01.0: fence driver on ring 7 use gpu addr 0x0000000f02400400, cpu addr 0xffffc900006f9400
[   16.396847] amdgpu 0000:00:01.0: fence driver on ring 8 use gpu addr 0x0000000f02400480, cpu addr 0xffffc900006f9480
[   16.396932] amdgpu 0000:00:01.0: using built-in radeon/kabini_sdma.bin
[   16.396938] firmware_class: __allocate_fw_buf: fw-radeon/kabini_sdma1.bin buf=ffff880004597b40
[   16.396957] amdgpu 0000:00:01.0: loading /lib/firmware/updates/4.14.10-tinycore64/radeon/kabini_sdma1.bin failed with error -2
[   16.396966] amdgpu 0000:00:01.0: loading /lib/firmware/updates/radeon/kabini_sdma1.bin failed with error -2
[   16.396975] amdgpu 0000:00:01.0: loading /lib/firmware/4.14.10-tinycore64/radeon/kabini_sdma1.bin failed with error -2
[   16.397003] amdgpu 0000:00:01.0: direct-loading radeon/kabini_sdma1.bin
[   16.397009] firmware_class: fw_set_page_data: fw-radeon/kabini_sdma1.bin buf=ffff880004597b40 data=ffffc90000505000 size=4456
[   16.397093] amdgpu 0000:00:01.0: fence driver on ring 9 use gpu addr 0x0000000f02400500, cpu addr 0xffffc900006f9500
[   16.397205] amdgpu 0000:00:01.0: fence driver on ring 10 use gpu addr 0x0000000f02400580, cpu addr 0xffffc900006f9580