Hello,
We are interested in running OpenWRT on the Miktrotik KNOT gateway. I have a gateway on my desk but have not yet seen any OpenWRT release for it. I'm willing to add the device in trunk but before I started my efforts I wanted to make sure nobody else is already doing this. In any case I want to help 
Kind regards,
Daan
This might be using the very similar hw ? [wAP LR8 kit]
except without 3g and bluetooth and gpio pins
Initial support already done below
(https://mikrotik.com/product/wap_lr8_kit)
https://github.com/rogerpueyo/openwrt/tree/ath79-mikrotik-wapr-2nd
I don't have one of these, but am happy to help.
If you want some ideas to get started:
Have a look at the FCC submission photos to check the parts used: https://fccid.io/TV7924BT5BG77/Internal-Photos/Internal-Photos-5281991
Base your work on the hAP ac lite: https://github.com/openwrt/openwrt/pull/3348/files, and strip from it any usage of devices / GPIOs that are not present in KNOT.
From RouterOS, export your licence, the routerboot details, and generate a supout. Copy these to your computer.
Decode the supout with decode_supout.py, and look through it for details
Check the RouterOS GPL dump for this device (you will need to request this from Mikrotik Support) for GPIO details. There is an old dump available here: https://github.com/robimarko/routeros-GPL/blob/b5c44a2d0f939bec0c219ee21e1d549bd6c10cb3/linux_3_3_5_patch_RouterOS644/arch/mips/rb/platform.c
+static struct platform_device rb924_hb_led_device = {
+ .name = "leds-rb",
+ .id = -1,
+ .dev = {
+ .platform_data = &(unsigned[]) {
+ PLED(ext_pin5, 0, GPIOLIB, PLED_CFG_INPUT),
+ PLED(power_led, 4, GPIOLIB, PLED_CFG_INV | PLED_CFG_ON),
+ PLDI(button, 16, GPIOLIB),
+ // keep lte in reset until usb drivers are loaded
+ PLED(lte_reset, 17, GPIOLIB, PLED_CFG_ON),
+
+ PLDI(eth_led, RB400_SSR_GPIO_BASE + 0, GPIOLIB),
+ PLDI(eth2_led, RB400_SSR_GPIO_BASE + 1, GPIOLIB),
+ PLDI(poe_led, RB400_SSR_GPIO_BASE + 2, GPIOLIB),
+ PLDI(gps_led, RB400_SSR_GPIO_BASE + 3, GPIOLIB),
+ PLDI(wlan_led, RB400_SSR_GPIO_BASE + 4, GPIOLIB),
+ PLED(pcie_power_off, RB400_SSR_GPIO_BASE + 5, GPIOLIB,
+ PLED_CFG_INV | PLED_CFG_KEEP),
+ PLED(uart_select, RB400_SSR_GPIO_BASE + 6, GPIOLIB,
+ PLED_CFG_ON),
+ 0
+ },
+ },
+};
+
+static struct platform_device rb924r4_hb_led_device = {
+ .name = "leds-rb",
+ .id = -1,
+ .dev = {
+ .platform_data = &(unsigned[]) {
+ PLED(ext_pin5, 0, GPIOLIB, PLED_CFG_INPUT),
+ PLED(power_led, 4, GPIOLIB, PLED_CFG_INV | PLED_CFG_ON),
+ PLD(usb_power_off, 13, GPIOLIB),
+ PLDI(button, 16, GPIOLIB),
+ // keep lte in reset until usb drivers are loaded
+ PLED(lte_reset, 17, GPIOLIB, PLED_CFG_ON),
+
+ PLDI(eth_led, RB400_SSR_GPIO_BASE + 0, GPIOLIB),
+ PLDI(eth2_led, RB400_SSR_GPIO_BASE + 1, GPIOLIB),
+ PLDI(poe_led, RB400_SSR_GPIO_BASE + 2, GPIOLIB),
+ PLDI(gps_led, RB400_SSR_GPIO_BASE + 3, GPIOLIB),
+ PLDI(wlan_led, RB400_SSR_GPIO_BASE + 4, GPIOLIB),
+ PLED(uart_select, RB400_SSR_GPIO_BASE + 6, GPIOLIB,
+ PLED_CFG_ON),
+ PLDI(pcie_power_off, RB400_SSR_GPIO_BASE + 7, GPIOLIB),
+ 0
+ },
+ },
+};
+
+static struct spi_board_info rb924_ssr_spi_misc = {
+ .modalias = "rb400-spi-misc",
+ .max_speed_hz = 15000000,
+ .bus_num = 0,
+ .chip_select = 0,
+ .mode = SPI_MODE_3,
+ .platform_data = &(struct rb400_ssr_info) {
+ .strobe = 11,
+ .bytes = 1,
+ .val = 0x7f
+ },
+};
+static struct spi_board_info bt_spi_nRF52832 = {
+ .modalias = "spi-nRF52832",
+ .max_speed_hz = 8 * 1000 * 1000,
+ .bus_num = 0,
+ .chip_select = 2,
+ .mode = SPI_MODE_0,
+ .platform_data = &(struct nrf52_platform_data) {
+ .irq_gpio = 2,
+ .labels = {
+ HWMON_LBL_BOARD,
+ HWMON_LBL_SYSTEM,
+ HWMON_LBL_GPIO_EXT_PIN3,
+ HWMON_LBL_GPIO_EXT_PIN2,
+ },
+ .gpio = {
+ .pins = {
+ PLED(ext_pin4, 15, GPIOLIB, PLED_CFG_INV),
+ PLED(ext_pin6, 14, GPIOLIB, PLED_CFG_INV),
+ },
+ .names = {
+ "ext-pin4",
+ "ext-pin6",
+ },
+ },
+ },
+};
+static struct platform_device rb924_spi_device = {
+ .name = "rb900-spi",
+ .id = -1,
+ .dev = {
+ .platform_data = &(struct spi_board_info *[]) {
+ &rb924_ssr_spi_misc,
+ &slow_large_spi_nor,
+ &bt_spi_nRF52832,
+ NULL
+ },
+ },
+};
+static struct platform_device rb924_uart_device = {
+ .name = "rb924-at-uart",
+ .id = -1,
+};
+
+
+static struct hwopt_device rb924_hb_devices[] = {
+ { &rb700_ehci_device, HW_OPT_HAS_USB, 0 },
+ { &ar9340_gpio_device, 0, 0 },
+ { &rb924_spi_device, 0, 0 },
+ { &rb924_uart_device, 0, 0 },
+ { &rb924_hb_led_device, 0, HW_OPT_RB924_r4 },
+ { &rb924r4_hb_led_device, HW_OPT_RB924_r4, 0 },
+ { &ar9330_wlan_device, HW_OPT_HAS_WIFI, 0 },
+ { &mAP2_poeout_device, 0, 0 },
+ { &maphb_eth_device, 0, 0 }
+};
+
+static struct platform_device crs332_led_device = {
+ .name = "leds-rb",
I would usually jailbreak, dump the SPI-NOR, dmesg, and watch the gpio registers while I switch functions on and off in RouterOS (but these might all be in the GPL dump). This will be complicated by the oldest RouterOS for this device not having a current jailbreak. You might be able to use @adron's tools: https://github.com/adron-s/mtik_initrd_hacks. If not able to jailbreak, I will open the board and dump the NOR with a SOIC8 clip.
Have a look at the SoC datasheet: https://github.com/Deoptim/atheros and the linux SoC drivers
You might need to use pinctrl to get the bt cs working, similar to: https://github.com/openwrt/openwrt/pull/3295#issuecomment-677976211. Check the linux driver or SoC datasheet to work our the pinctrl values.
Apart from getting actual OpenWRT support for the device, i have already listed some projects related to actually using the device on the previous post.
@dpape what functionality do you specifically require to get working in OpenWRT for this device ?
The maturity of LoRa use cases withing OpenWRT is not very high in my opinion at the moment
apart from connecting to the ThingsNetwork