serial aliases in dtb

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index c89faf2ca7..fb3559701e 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -280,6 +280,8 @@ static void create_fdt(VirtMachineState *vms)
         }
     }
 
+    qemu_fdt_add_subnode(fdt, "/aliases");
+
     /* Clock node, for the benefit of the UART. The kernel device tree
      * binding documentation claims the PL011 node clock properties are
      * optional but in practice if you omit them the kernel refuses to
@@ -907,11 +909,18 @@ static void create_uart(const VirtMachineState *vms, int uart,
     qemu_fdt_setprop(ms->fdt, nodename, "clock-names",
                          clocknames, sizeof(clocknames));
 
+    /*
+     * We set the serial0, serial1 aliases so that Linux reliably
+     * assigns them to ttyAMA0, ttyAMA1 regardless of the order of the
+     * nodes in the dtb or any future changes to Linux's dtb parsing.
+     */
     switch(uart) {
     case VIRT_UART0:
         qemu_fdt_setprop_string(ms->fdt, "/chosen", "stdout-path", nodename);
+        qemu_fdt_setprop_string(ms->fdt, "/aliases", "serial0", nodename);
         break;
     case VIRT_UART1:
+        qemu_fdt_setprop_string(ms->fdt, "/aliases", "serial1", nodename);
         if (vms->secure) {
             qemu_fdt_setprop_string(ms->fdt, nodename, "status", "disabled");
             qemu_fdt_setprop_string(ms->fdt, nodename, "secure-status", "okay");