Dear all,
I am trying to understand how to change the default pin of the u-boot (2020.01)
console for the Raspberry pi CM3+ board.
I am using yocto with meta-raspberrypi on the dunfell branch and how everything
works between the first stage bootloader, u-boot, u-boot internal device tree
and the kernel device tree is not really clear to me.
Here is what I would like to achieve:
1. Get UART0 or UART1 as the standard console for u-boot and the linux kernel
on pins 32 and 33
2. Make u-boot pass my device tree (stored in the boot partition) to the
kernel and not the device tree generated by the first stage bootloader
Regarding the first point, I already created a new device tree within u-boot
and set it as the default bootloader in my default config (see attached files).
Here is the different things I tried:
* Use UART0 on pins 32 and 33
* In the u-boot device tree:
chosen {
stdout-path = "serial0:115200n8";
}
...
&uart0 {
pinctrl-names= "default";
pinctrl-0 = <&uart0_gpio32>;
status = "okay";
}
* In the config.txt:
enable_uart=1
dtoverlay=uart0,txd0_pin=32,rxd0_pin=33,pin_func=7
* This works but only for the kernel, I don't get any output from u-boot
and can't stop the boot process.
* Use UART1 on pins 32 and 33: more or less the same modification but with
different values
I would like to know if there is an other file I should modify to get this
working. When I use the uart0 or uart1 on pin 14 and 15 everything works
properly.
The second point seems pretty clear to me. I will change the bootscript and
load the file with the fatload command and pass it to the kernel. However I
wonder if it might create some problems if the first stage bootloader has
already reserved the pins.
Finally when u-boot is starting correctly I have the following warning and I
was not able to find any explanation on it:
U-Boot 2020.01 (Jan 06 2020 - 20:56:31 +0000)
DRAM: 948 MiB
RPI Compute Module 3+ (0xa02100)
MMC: mmc@7e202000: 0
Loading Environment from FAT... WARNING at
drivers/mmc/bcm2835_sdhost.c:410/bcm2835_send_command()!
WARNING at drivers/mmc/bcm2835_sdhost.c:410/bcm2835_send_command()!
*** Warning - bad CRC, using default environment
In: serial
Out: vidconsole
Err: vidconsole
Net: No ethernet found.
starting USB...
Bus usb@7e980000: scanning bus usb@7e980000 for devices... 1 USB Device(s) found
scanning usb for storage devices... 0 Storage Device(s) found
Hit any key to stop autoboot: 0
WARNING at drivers/mmc/bcm2835_sdhost.c:410/bcm2835_send_command()!
WARNING at drivers/mmc/bcm2835_sdhost.c:410/bcm2835_send_command()!
switch to partitions #0, OK
mmc0(part 0) is current device
Scanning mmc 0:1...
Found U-Boot script /boot.scr
Should I simply ignore it ?
Thank you in advance for your time.
Best regards
Romain
________________________________
Romain Crausaz
Development
DIGI SENS Switzerland AG
Freiburgstr. 65
CH-3280 Murten
Telefon: +41 26 672 9876
Email: [email protected]<mailto:[email protected]>
[cid:digisens_34df8dfe-0639-4acb-9e8d-0efd75e7b3a8.png]
www.digisens.ch<http://www.digisens.ch>
diff --git a/configs/rpi_cm3_digisens_defconfig b/configs/rpi_cm3_digisens_defconfig
index e69de29bb2..c4f5538af1 100644
--- a/configs/rpi_cm3_digisens_defconfig
+++ b/configs/rpi_cm3_digisens_defconfig
@@ -0,0 +1,48 @@
+CONFIG_ARM=y
+CONFIG_ARCH_CPU_INIT=y
+CONFIG_ARCH_BCM283X=y
+CONFIG_SYS_TEXT_BASE=0x00008000
+CONFIG_TARGET_RPI_3_32B=y
+CONFIG_SYS_MALLOC_F_LEN=0x2000
+CONFIG_ENV_SIZE=0x4000
+CONFIG_NR_DRAM_BANKS=1
+CONFIG_DISTRO_DEFAULTS=y
+CONFIG_OF_BOARD_SETUP=y
+CONFIG_USE_PREBOOT=y
+CONFIG_PREBOOT="usb start"
+CONFIG_MISC_INIT_R=y
+# CONFIG_DISPLAY_CPUINFO is not set
+# CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_SYS_PROMPT="U-Boot> "
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_FS_UUID=y
+CONFIG_OF_EMBED=y
+CONFIG_DEFAULT_DEVICE_TREE="bcm2837-rpi-cm3-digisens"
+CONFIG_ENV_FAT_INTERFACE="mmc"
+CONFIG_ENV_FAT_DEVICE_AND_PART="0:1"
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
+CONFIG_DM_KEYBOARD=y
+CONFIG_DM_MMC=y
+CONFIG_MMC_SDHCI=y
+CONFIG_MMC_SDHCI_BCM2835=y
+CONFIG_PHYLIB=y
+CONFIG_DM_ETH=y
+CONFIG_PINCTRL=y
+# CONFIG_PINCTRL_GENERIC is not set
+# CONFIG_REQUIRE_SERIAL_CONSOLE is not set
+CONFIG_USB=y
+CONFIG_DM_USB=y
+CONFIG_USB_DWC2=y
+CONFIG_USB_KEYBOARD=y
+CONFIG_USB_HOST_ETHER=y
+CONFIG_USB_ETHER_LAN78XX=y
+CONFIG_USB_ETHER_SMSC95XX=y
+CONFIG_DM_VIDEO=y
+CONFIG_VIDEO_BPP32=y
+CONFIG_SYS_WHITE_ON_BLACK=y
+CONFIG_CONSOLE_SCROLL_LINES=10
+CONFIG_PHYS_TO_BUS=y
+CONFIG_OF_LIBFDT_OVERLAY=y
diff --git a/arch/arm/dts/bcm2837-rpi-cm3-digisens.dts b/arch/arm/dts/bcm2837-rpi-cm3-digisens.dts
index e69de29bb2..f6c0efd18d 100644
--- a/arch/arm/dts/bcm2837-rpi-cm3-digisens.dts
+++ b/arch/arm/dts/bcm2837-rpi-cm3-digisens.dts
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+#include "bcm2837.dtsi"
+#include "bcm2836-rpi.dtsi"
+#include "bcm283x-rpi-smsc9514.dtsi"
+#include "bcm283x-rpi-usb-host.dtsi"
+
+/ {
+ compatible = "raspberrypi,3-compute-module", "brcm,bcm2837";
+ model = "Raspberry Pi Compute Module 3 DIGI-SENS baseboard";
+
+ memory@0 {
+ reg = <0 0x40000000>;
+ };
+
+ leds {
+ act {
+ gpios = <&expgpio 2 GPIO_ACTIVE_HIGH>;
+ };
+ };
+
+ chosen {
+ /* 8250 auxiliary UART instead of pl011 */
+ stdout-path = "serial1:115200n8";
+ };
+
+ reg_3v3: fixed-regulator {
+ compatible = "regulator-fixed";
+ regulator-name = "3V3";
+ regulator-min-microvolt = <3300000>;
+ regulator-max-microvolt = <3300000>;
+ regulator-always-on;
+ };
+
+ reg_1v8: fixed-regulator {
+ compatible = "regulator-fixed";
+ regulator-name = "1V8";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ regulator-always-on;
+ };
+};
+
+&gpio {
+ /*
+ * This is based on the official GPU firmware DT blob.
+ *
+ * Legend:
+ * "NC" = not connected (no rail from the SoC)
+ * "FOO" = GPIO line named "FOO" on the schematic
+ * "FOO_N" = GPIO line named "FOO" on schematic, active low
+ */
+ gpio-line-names =
+ /* I2C0 */
+ "00-I2C0_SDA",
+ "01-I2C0_SCL",
+
+ /* GPIO */
+ "02-GPIO2",
+ "03-GPIO3",
+ "04-GPIO4",
+ "05-GPIO5",
+ "06-GPIO6",
+
+ /* SPI0 */
+ "07-SPI0_CE1",
+ "08-SPI0_CE2",
+ "09-SPI0_MISO",
+ "10-SPI0_MOSI",
+ "11-SPI0_SCLK",
+
+ /* GPIO */
+ "12-GPIO12",
+ "13-GPIO13",
+ "14-GPIO14",
+ "15-GPIO15",
+ "16-GPIO16",
+
+ /* MRST */
+ "17-MRST",
+
+ /* SC16IS752 */
+ "18-SC16IS752_IRQ",
+ "19-SC16IS752_RESET",
+
+ /* RTC */
+ "20-RTC_PF0",
+
+ /* GPIO */
+ "21-GPIO21",
+
+ /* SDCARD0 */
+ "22-SD0_CLK",
+ "23-SD0_CMD",
+ "24-SD0_DATA0",
+ "25-SD0_DATA1",
+ "26-SD0_DATA2",
+ "27-SD0_DATA3",
+
+ /* GPIO */
+ "28-GPIO28",
+ "29-GPIO29",
+
+ /* UART0 */
+ "30-UART0_CTS",
+ "31-UART0_RTS",
+ "32-UART0_TXD",
+ "33-UART0_RXD",
+
+ /* SDCARD1 */
+ "34-SD1_CLK",
+ "35-SD1_CMD",
+ "36-SD1_DATA0",
+ "37-SD1_DATA1",
+ "38-SD1_DATA2",
+ "39-SD1_DATA3",
+
+ /* SPI2 */
+ "40-SPI2_MISO",
+ "41-SPI2_MOSI",
+ "42-SPI2_SCLK",
+ "43-SPI2_CE0",
+ "44-SPI2_CE1",
+ "45-SPI2_CE2",
+
+ /* UNKNOWN */
+ "GPIO46",
+ "GPIO47",
+ /* Used by eMMC */
+ "SD_CLK_R",
+ "SD_CMD_R",
+ "SD_DATA0_R",
+ "SD_DATA1_R",
+ "SD_DATA2_R",
+ "SD_DATA3_R";
+
+ pinctrl-0 = <&gpioout &alt0>;
+};
+
+&firmware {
+ expgpio: gpio {
+ compatible = "raspberrypi,firmware-gpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ gpio-line-names = "HDMI_HPD_N",
+ "EMMC_EN_N",
+ "NC",
+ "NC",
+ "NC",
+ "NC",
+ "NC",
+ "NC";
+ status = "okay";
+ };
+};
+
+&hdmi {
+ hpd-gpios = <&expgpio 1 GPIO_ACTIVE_LOW>;
+};
+
+&uart1 {
+ pinctrl-names = "default";
+ pinctrl-0 = <&uart1_gpio32>;
+ status = "okay";
+};
+
+
+&sdhost {
+ pinctrl-names = "default";
+ pinctrl-0 = <&sdhost_gpio48>;
+ bus-width = <4>;
+ vmmc-supply = <®_3v3>;
+ vqmmc-supply = <®_1v8>;
+ status = "okay";
+};
