copy bcm2711-rpi-4-b.dtb (with UART path) from kernel build

related to gokrazy/gokrazy#48

0103-expose-UART0-ttyAMA0-on-GPIO-14-15-disable-UART1-tty.patch

@@ -0,0 +1,72 @@
+--- ./arch/arm/boot/dts/bcm2711-rpi-4-b.dts.O	2020-04-04 13:55:20.803705272 +0200
++++ ./arch/arm/boot/dts/bcm2711-rpi-4-b.dts	2020-04-04 14:00:57.649047011 +0200
+@@ -10,7 +10,8 @@
+
+ 	chosen {
+ 		/* 8250 auxiliary UART instead of pl011 */
+-		stdout-path = "serial1:115200n8";
++		stdout-path = "";
++		bootargs = "earlyprintk console=tty1"; 
+ 	};
+
+ 	/* Will be filled by the bootloader */
+@@ -37,6 +38,14 @@
+ 		};
+ 	};
+
++	aliases {
++		/* required for the firmware as per
++		 * https://github.com/raspberrypi/firmware/issues/752#issuecomment-283331328
++		 * */
++		uart0 = &uart0;
++		uart1 = &uart1;
++	};
++
+ 	wifi_pwrseq: wifi-pwrseq {
+ 		compatible = "mmc-pwrseq-simple";
+ 		reset-gpios = <&expgpio 1 GPIO_ACTIVE_LOW>;
+@@ -57,6 +66,14 @@
+ 	};
+ };
+
++&gpio {
++       uart0_pins: uart0_pins {
++               brcm,pins = <14 15>;
++               brcm,function = <BCM2835_FSEL_ALT0>;
++               brcm,pulls = <0 2>;
++       };
++};
++
+ &firmware {
+ 	expgpio: gpio {
+ 		compatible = "raspberrypi,firmware-gpio";
+@@ -117,25 +134,16 @@
+ 	};
+ };
+
+-/* uart0 communicates with the BT module */
++/* uart0 is mapped to the pin header */
+ &uart0 {
+ 	pinctrl-names = "default";
+-	pinctrl-0 = <&uart0_ctsrts_gpio30 &uart0_gpio32>;
+-	uart-has-rtscts;
++	pinctrl-0 = <&uart0_pins>;
+ 	status = "okay";
+-
+-	bluetooth {
+-		compatible = "brcm,bcm43438-bt";
+-		max-speed = <2000000>;
+-		shutdown-gpios = <&expgpio 0 GPIO_ACTIVE_HIGH>;
+-	};
+ };
+
+-/* uart1 is mapped to the pin header */
++/* uart1 is disabled */
+ &uart1 {
+-	pinctrl-names = "default";
+-	pinctrl-0 = <&uart1_gpio14>;
+-	status = "okay";
++	status = "disabled";
+ };
+
+ &vchiq {

cmd/gokr-build-kernel/build.go

@@ -1054,7 +1054,7 @@ func main() {
 
 	log.Printf("unpacking kernel source")
 	if err := exec.Command("tar", "xf", filepath.Base(latest)).Run(); err != nil {
-		log.Fatal("untar: %v", err)
+		log.Fatalf("untar: %v", err)
 	}
 
 	srcdir := strings.TrimSuffix(filepath.Base(latest), ".tar.xz")
@@ -1084,4 +1084,8 @@ func main() {
 	if err := copyFile("/tmp/buildresult/bcm2710-rpi-3-b-plus.dtb", "arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b-plus.dtb"); err != nil {
 		log.Fatal(err)
 	}
+
+	if err := copyFile("/tmp/buildresult/bcm2711-rpi-4-b.dtb", "arch/arm64/boot/dts/broadcom/bcm2711-rpi-4-b.dtb"); err != nil {
+		log.Fatal(err)
+	}
 }

cmd/gokr-rebuild-kernel/kernel.go

@@ -44,6 +44,7 @@ var patchFiles = []string{
 	// serial
 	"0101-expose-UART0-ttyAMA0-on-GPIO-14-15-disable-UART1-tty.patch",
 	"0102-expose-UART0-ttyAMA0-on-GPIO-14-15-disable-UART1-tty.patch",
+	"0103-expose-UART0-ttyAMA0-on-GPIO-14-15-disable-UART1-tty.patch",
 }
 
 func copyFile(dest, src string) error {
@@ -157,6 +158,10 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	dtb4Path, err := find("bcm2711-rpi-4-b.dtb")
+	if err != nil {
+		log.Fatal(err)
+	}
 
 	// Copy all files into the temporary directory so that docker
 	// includes them in the build context.
@@ -242,4 +247,9 @@ func main() {
 	if err := copyFile(dtbPlusPath, filepath.Join(tmp, "bcm2710-rpi-3-b-plus.dtb")); err != nil {
 		log.Fatal(err)
 	}
+
+	if err := copyFile(dtb4Path, filepath.Join(tmp, "bcm2711-rpi-4-b.dtb")); err != nil {
+		log.Fatal(err)
+	}
+
 }