+.data
+
+; TODO
+.org 0x300
+int2hex:
+ ;3210
+ .fill 0x33323130
+ ;7654
+ .fill 0x37363534
+ ;ba98
+ .fill 0x62613938
+ ;fedc
+ .fill 0x66656463
+.text
+; TODO
+.org 0x300
+ .define UART_BASE, 0x2000
+ .define UART_STATUS, 0x0
+ .define UART_RECV, 0xc
+ .define UART_TRANS, 0x8
+
+ .define UART_TRANS_EMPTY, 0x1
+ .define UART_RECV_NEW, 0x2
+
+u_recv_byte:
+ ldw r3, UART_STATUS(r10)
+ andx r3, UART_RECV_NEW
+ brzs+ u_recv_byte; branch if zero
+ xor r0, r0, r0
+ ldw r0, UART_RECV(r10)
+ ret
+
+u_send_byte:
+ ldw r9, UART_STATUS(r10)
+ andx r9, UART_TRANS_EMPTY
+ brnz+ u_send_byte ; branch if not zero
+ stb r1, UART_TRANS(r10)
+ ret
+
+u_send_uint:
+ addi r8, r1, 0
+ ;usb_sendbuffersafe ("0x", 2);
+ xor r1, r1, r1
+ ldi r1, 0x30
+ call u_send_byte
+ xor r1, r1, r1
+ ldi r1, 0x78
+ call u_send_byte
+ ;j = 0
+ xor r7, r7, r7
+ xor r6, r6, r6
+ ldi r6, int2hex@lo
+ ldih r6, int2hex@hi
+u_send_uint_loop:
+ ;for (j = 0; j < 8; ++j) {
+ cmpi r7, 8
+ reteq
+ ;usb_sendbuffersafe (&int2hex[(i >> 28) & 0xf], 1);
+ lrs r1, r8, 28
+ andx r1, 0xf
+ add r9, r6, r1
+ ldb r1, 0(r9)
+ call u_send_byte
+ ;i <<= 4;
+ lls r8, r8, 4
+ addi r7, r7, 1
+ br u_send_uint_loop
+
+u_send_string:
+ ; r1 = addr
+ ; r2 = len
+ addi r3, r1, 0
+u_send_string_int:
+ cmpi r2, 0
+ reteq-
+ ldb r1, 0(r3)
+ call u_send_byte
+ addis r2, r2, 0-1
+ addi r3, r3, 1
+ br u_send_string_int
+
+u_send_newline:
+ xor r1, r1, r1
+ ldi r1, 0x0a
+ call u_send_byte
+ ldi r1, 0x0d
+ call u_send_byte
+ ret
+
+u_init:
+ xor r10, r10, r10
+ ldi r10, UART_BASE@lo
+ ldih r10, UART_BASE@hi
+ ret