FreeCalypso > hg > freecalypso-sw
diff target-utils/libbase/serio.S @ 991:5cff3579814c
target-utils: libbase factored out of libcommon
The library dependency order is now strictly unidirectional
| author | Mychaela Falconia <falcon@ivan.Harhan.ORG> |
|---|---|
| date | Wed, 30 Dec 2015 20:48:12 +0000 |
| parents | target-utils/libcommon/serio.S@d7591faa1258 |
| children | a7b0b426f9ca |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/target-utils/libbase/serio.S Wed Dec 30 20:48:12 2015 +0000 @@ -0,0 +1,34 @@ +#include "ns16550.h" + +@ this module implements the elementary serial I/O operations + + .text + .code 32 + .global serial_out +serial_out: + ldr r1, =uart_base + ldr r2, [r1] +1: ldrb r3, [r2, #NS16550_LSR] + tst r3, #NS16550_LSR_THRE + beq 1b + strb r0, [r2, #NS16550_THR] + bx lr + + .global serial_in_poll +serial_in_poll: + ldr r1, =uart_base + ldr r2, [r1] + ldrb r3, [r2, #NS16550_LSR] + tst r3, #NS16550_LSR_DR + ldrneb r0, [r2, #NS16550_RBR] + mvneq r0, #0 + bx lr + + .global serial_flush +serial_flush: + ldr r1, =uart_base + ldr r2, [r1] +1: ldrb r3, [r2, #NS16550_LSR] + tst r3, #NS16550_LSR_TEMP + beq 1b + bx lr