Start new assembler

1 files changed, 44 insertions, 0 deletions

diff --git a/newasm/uart.s b/newasm/uart.s
new file mode 100644
index 0000000..c4abb8a
--- /dev/null
+++ b/newasm/uart.s
@@ -0,0 +1,44 @@
+.syntax unified
+.cpu cortex-m0plus
+.thumb
+
+.type uart_send, %function
+.type uart_recv, %function
+.type send_hex, %function
+
+.global uart_send
+.global uart_recv
+.global send_hex
+
+uart_send:  LDR     R1, =0x40034000
+            MOVS    R3, 0x20
+1:          LDR     R2, [R1, 0x18]
+            TST     R2, R3
+            BNE     1b
+            STRB    R0, [R1]
+            BX      LR
+
+uart_recv:  LDR     R1, =0x40034000
+            MOVS    R3, 0x10
+1:          LDR     R2, [R1, 0x18]
+            TST     R2, R3
+            BNE     1b
+            LDRB    R0, [R1]
+            BX      LR
+
+send_hex:   PUSH    {R4, R5, LR}
+            MOVS    R4, R0
+            MOVS    R5, 8
+0:          MOVS    R0, 0x1C
+            RORS    R4, R0
+            MOVS    R0, 0x0F
+            ANDS    R0, R4
+            CMP     R0, 0x9
+            BHI     1f
+            ADDS    R0, 0x30
+            B       2f
+1:          ADDS    R0, 0x37
+2:          BL      uart_send
+            SUBS    R5, 1
+            BNE     0b
+            POP     {R4, R5, PC}