rpi-cmdline: Fix earlycon for Raspberry Pi 5

The UART for earlycon has moved from UART0 on the 40 pin GPIO header
(now wired through the RP1 south bridge chip), to a dedicated debug
header. Using the old configuration with a Raspberry Pi 5 makes
the kernel hang with the fan spinning at full speed.

Change-type: patch
Signed-off-by: Michal Toman <michalt@balena.io>

layers/meta-balena-raspberrypi/recipes-bsp/bootfiles/rpi-cmdline.bbappend

@@ -3,6 +3,11 @@ CMDLINE += " dwc_otg.lpm_enable=0 rootwait"
 CMDLINE += "${OS_KERNEL_CMDLINE} ${@oe.utils.conditional('SIGN_API','','',"${OS_KERNEL_SECUREBOOT_CMDLINE}",d)}"
 CMDLINE =+ " ${@bb.utils.contains('DISTRO_FEATURES','osdev-image',"earlycon=uart8250,mmio32,0xfe215040 console=tty1","",d)}"
 
+# earlycon on the Pi5 is on a dedicated debug header,
+# while UART0 on the 40 pin GPIO header is wired behind the RP1 south bridge chip
+CMDLINE:remove:raspberrypi5 = "earlycon=uart8250,mmio32,0xfe215040"
+CMDLINE:prepend:raspberrypi5 := " ${@bb.utils.contains('DISTRO_FEATURES','osdev-image',"earlycon=pl011,0x107d001000,115200n8","",d)}"
+
 # See https://github.com/raspberrypi/linux/commit/9b0efcc1ec497b2985c6aaa60cd97f0d2d96d203
 CMDLINE += " cgroup_enable=memory"
 CMDLINE:remove = "root=/dev/mmcblk0p2"