1 files changed, 10 insertions, 0 deletions
diff --git a/uart.s b/uart.s
index 5b03024..39e631b 100644
--- a/uart.s
+++ b/uart.s
@@ -19,6 +19,10 @@
 .equ UARTLCR_H_OFST, 0x2c
 .equ UARTCR_OFST, 0x30
 
+.equ IO_BANK0_BASE, 0x40014000
+.equ GPIO0_CTRL_OFST, 0x04
+.equ GPIO1_CTRL_OFST, 0x0c
+
 .equ ATOMIC_CLEAR,    0x3000
 
 .type setup_uart, %function
@@ -26,6 +30,12 @@
 
 setup_uart:
 
+  // Configure GPIO 0 and 1 as UART0
+  ldr r1, =IO_BANK0_BASE
+  movs r0, 2 // UART function = 2
+  str r0, [r1, GPIO0_CTRL_OFST]
+  str r0, [r1, GPIO1_CTRL_OFST]
+
   // Deassert the reset
   ldr r1, =(RESETS_BASE + ATOMIC_CLEAR)
   movs r0, 1