+ .macro senduart,rd,rx
+ strb \rd, [\rx]
+ .endm
+
+ .macro busyuart,rd,rx
+1002: ldrb \rd, [\rx, #0x14]
+ and \rd, \rd, #0x60
+ teq \rd, #0x60
+ bne 1002b
+ .endm
+
+ .macro waituart,rd,rx
+1001: ldrb \rd, [\rx, #0x18]
+ tst \rd, #0x10
+ beq 1001b
+ .endm