I just planned to get the latest kernel running. Unfortunately these days I'm busy for a little help to my friend to program a MCU.
I'll get back to you ASAP. Perhaps in few hours.
EDIT
I updated the system and kernel. In few words, your make is the BEST. The system started latest kernel flawlessly.
Then, I tried the new dtb rk2388-tinker-s.dtb, from mainline. It boot smoothly, but the WiFi is not there and the NIC also fails to do the simplest things.
$this->bbcode_second_pass_code('', '$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 88:d7:f6:c2:f1:42 brd ff:ff:ff:ff:ff:ff
=======================================
$ lsmod
Module                  Size  Used by
realtek                16384  1
snd_soc_hdmi_codec     16384  1
dw_hdmi_cec            16384  0
dw_hdmi_i2s_audio      16384  0
snd_soc_simple_card    16384  0
snd_soc_simple_card_utils    16384  1 snd_soc_simple_card
rockchip_rga           20480  0
v4l2_mem2mem           24576  1 rockchip_rga
snd_soc_rockchip_i2s    16384  2
videobuf2_dma_sg       16384  1 rockchip_rga
videobuf2_memops       16384  1 videobuf2_dma_sg
videobuf2_v4l2         24576  2 v4l2_mem2mem,rockchip_rga
snd_soc_rockchip_pcm    16384  1 snd_soc_rockchip_i2s
videobuf2_common       45056  3 v4l2_mem2mem,videobuf2_v4l2,rockchip_rga
snd_soc_core          159744  5 snd_soc_rockchip_i2s,snd_soc_hdmi_codec,snd_soc_simple_card_utils,snd_soc_rockchip_pcm,snd_soc_simple_card
ac97_bus               16384  1 snd_soc_core
snd_pcm_dmaengine      16384  1 snd_soc_core
rk_crypto              24576  0
dw_wdt                 16384  0
snd_usb_audio         188416  0
snd_usbmidi_lib        28672  1 snd_usb_audio
snd_hwdep              16384  1 snd_usb_audio
evdev                  24576  2
joydev                 20480  0
snd_rawmidi            32768  1 snd_usbmidi_lib
snd_seq_device         16384  1 snd_rawmidi
snd_pcm                94208  4 snd_usb_audio,snd_pcm_dmaengine,snd_soc_hdmi_codec,snd_soc_core
snd_timer              32768  1 snd_pcm
pwm_rockchip           16384  0
dwmac_rk               28672  0
rockchipdrm            94208  0
stmmac_platform        20480  1 dwmac_rk
analogix_dp            32768  1 rockchipdrm
stmmac                126976  2 stmmac_platform,dwmac_rk
dw_hdmi                32768  2 rockchipdrm,dw_hdmi_i2s_audio
rockchip_saradc        16384  0
uio_pdrv_genirq        16384  0
uio                    20480  1 uio_pdrv_genirq
sch_fq_codel           20480  2
crypto_user            20480  0
ip_tables              28672  0
x_tables               32768  1 ip_tables
')
Here's what journalctl -b said during the boot.
Regarding the SD card detection, still best the parameters we put earlier.
$this->bbcode_second_pass_code('', '$ cat /boot/boot.txt 
    # After modifying, run ./mkscr
    setenv rootcmd "LABEL=TB-MM-root"
    setenv fdtfile rk3288-tinker-s.dtb
    setenv bootargs "console=ttyS2,115200n8 root=${rootcmd} rw rootwait"
    if load ${devtype} ${devnum}:${bootpart} ${kernel_addr_r} /boot/zImage; then
      if load ${devtype} ${devnum}:${bootpart} ${fdt_addr_r} /boot/dtbs/${fdtfile}; then
        fdt addr ${fdt_addr_r}
        fdt resize
        fdt set /dwmmc@ff0c0000 broken-cd
#        fdt set /usb@ff500000 no-relinquish-port
        if load ${devtype} ${devnum}:${bootpart} ${ramdisk_addr_r} /boot/initramfs-linux.img; then
          bootz ${kernel_addr_r} ${ramdisk_addr_r}:${filesize} ${fdt_addr_r};
        else
          bootz ${kernel_addr_r} - ${fdt_addr_r};
        fi;
      fi;
    fi')
Summarizing, I'll put back rk3288-tinkerS.dtb, which gives the WiFi working with the latest kernel. Perhaps still crash when starting SoftAP with the module 80211.
BTW, I just noted that the 80211 is not loaded, even the NIC wants it.
If you need, I'll post the data when I boot with your rk3288-tinkerS.dtb.
			
		

