1 files changed, 46 insertions, 0 deletions
diff --git a/src/uart.S b/src/uart.S
new file mode 100644
index 0000000..bd98bac
--- /dev/null
+++ b/src/uart.S
@@ -0,0 +1,46 @@
+.section ".text"
+
+.globl uart_init
+uart_init:
+    //*UART0_IMSC = 1 << 4;
+    mov r2, #0x1038
+    movt r2, #0x3F20
+    mov r3, #0b10000
+    str r3, [r2]
+    //*IRQ_ENABLE2 = 1 << 25;
+    mov r2, #0xB214
+    movt r2, #0x3F00
+    mov r3, #0
+    movt r3, #0b1000000000
+    str r3, [r2]
+    //*GPU_INTERRUPTS_ROUTING = 0x00;
+    mov r2, #0x000C
+    movt r2, #0x4000
+    eor r3, r3
+    str r3, [r2]
+    bx lr
+
+.globl uart_char
+uart_char:
+    mov r2, #0x1000
+    movt r2, #0x3f20
+uart_char.loop:
+    ldr r3, [r2, #24]
+    tst r3, #0b100000
+    bne uart_char.loop
+    str r0, [r2]
+    bx lr
+
+.globl uart_string
+uart_string:
+    push    {r4, lr}
+    mov     r4, r0
+    ldrb    r0, [r0]
+    cmp     r0, #0
+    popeq   {r4, pc}
+uart_string.loop:
+    bl      uart_char
+    ldrb    r0, [r4, #1]!
+    cmp     r0, #0
+    bne     uart_string.loop
+    pop     {r4, pc}