bootromfun: geht noch immmer...

[calu.git] / 2_isa / src / bootrom.s

diff --git a/2_isa/src/bootrom.s b/2_isa/src/bootrom.s
index 2a46cfdabb8a38f695b8c955cbfce4607153b502..d38e1854527f517791893b82811e21e057a93780 100644 (file)
--- a/2_isa/src/bootrom.s
+++ b/2_isa/src/bootrom.s
@@ -25,15 +25,11 @@ main:
        ldi r11, PBASE@lo
        ldih r11, PBASE@hi
 poll:
-       ldw r3, UART_STATUS(r10)
-       andx r3, UART_RECV_NEW
-       brzs+ poll; branch if zero
-
        call recv_byte
        ; we received the enter bootrom sign
        xor r1, r1, r1
        cmpi r0, 0x48 ; 'H'
-       breq- bt_H
+       breq+ bt_H
        br poll ; else
 
 ;-----
@@ -41,7 +37,7 @@ send_byte:
        ldw r3, UART_STATUS(r10)
        andx r3, UART_TRANS_EMPTY
        brnz+ send_byte ; branch if not zero
-       stb r1, UART_TRANS(r10)
+       stw r1, UART_TRANS(r10)
        ret
 
 ;-----
@@ -62,7 +58,7 @@ recv_byte:
        andx r3, UART_RECV_NEW
        brzs+ recv_byte; branch if zero
        xor r0, r0, r0
-       ldb r0, UART_RECV(r10)
+       ldw r0, UART_RECV(r10)
        ret
 
 ;-----
@@ -89,6 +85,8 @@ recv_word:
 ;-----
 bootrom:
        call recv_byte
+       ldi r1, 0x50 ; 'P'
+       call send_byte
        br tehend
 
        xor r1, r1, r1