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bootromfun: okay, speicherzugriffe haben definitiv bei mein fpga ned [...]
[calu.git]
/
2_isa
/
src
/
bootrom.s
diff --git
a/2_isa/src/bootrom.s
b/2_isa/src/bootrom.s
index dc484d7fea490ffa0b0b5d321494cba2ea36319d..9ff1bf77d26158c56366cccb50566fb1be858a76 100644
(file)
--- a/
2_isa/src/bootrom.s
+++ b/
2_isa/src/bootrom.s
@@
-9,6
+9,10
@@
.define UART_TRANS_EMPTY, 0x1
.define UART_RECV_NEW, 0x2
.define UART_TRANS_EMPTY, 0x1
.define UART_RECV_NEW, 0x2
+ .define PBASE, 0x2030
+ .define PADDR, 0x4
+ .define PDATA, 0x8
+
;-----
start:
br+ main
;-----
start:
br+ main
@@
-18,16
+22,14
@@
start:
main:
ldi r10, UART_BASE@lo
ldih r10, UART_BASE@hi
main:
ldi r10, UART_BASE@lo
ldih r10, UART_BASE@hi
+ ldi r11, PBASE@lo
+ ldih r11, PBASE@hi
poll:
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'
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
;-----
br poll ; else
;-----
@@
-35,7
+37,7
@@
send_byte:
ldw r3, UART_STATUS(r10)
andx r3, UART_TRANS_EMPTY
brnz+ send_byte ; branch if not zero
ldw r3, UART_STATUS(r10)
andx r3, UART_TRANS_EMPTY
brnz+ send_byte ; branch if not zero
- st
b
r1, UART_TRANS(r10)
+ st
w
r1, UART_TRANS(r10)
ret
;-----
ret
;-----
@@
-56,12
+58,11
@@
recv_byte:
andx r3, UART_RECV_NEW
brzs+ recv_byte; branch if zero
xor r0, r0, r0
andx r3, UART_RECV_NEW
brzs+ recv_byte; branch if zero
xor r0, r0, r0
- ld
b
r0, UART_RECV(r10)
+ ld
w
r0, UART_RECV(r10)
ret
;-----
recv_word:
ret
;-----
recv_word:
- xor r0, r0, r0
xor r1, r1, r1
call recv_byte
or r1, r0, r1
xor r1, r1, r1
call recv_byte
or r1, r0, r1
@@
-79,13
+80,14
@@
recv_word:
or r1, r0, r1
addi r0, r1, 0
or r1, r0, r1
addi r0, r1, 0
-
ret
;-----
bootrom:
ret
;-----
bootrom:
- br tehend
call recv_byte
call recv_byte
+ ldi r1, 0x50 ; 'P'
+ call send_byte
+ br tehend
xor r1, r1, r1
cmpi r0, 0x57 ; 'W'
xor r1, r1, r1
cmpi r0, 0x57 ; 'W'
@@
-110,14
+112,16
@@
bootrom:
bt_H:
ldi r1, 0x4f ; 'O'
call send_byte
bt_H:
ldi r1, 0x4f ; 'O'
call send_byte
- ; br bootrom ; FIXME
- br tehend
+ xor r1, r1, r1
+ ldi r1, 0x41 ; 'A'
+ call send_byte
+ br bootrom
bt_W:
call recv_word ; receive addr
bt_W:
call recv_word ; receive addr
- mov r6, r0
+ stw r0, PADDR(r11)
call recv_word ; receive instr
call recv_word ; receive instr
- st
x r0, 0(r6
)
+ st
w r0, PDATA(r11
)
ldi r1, 0x44 ; 'D'
call send_byte
br bootrom
ldi r1, 0x44 ; 'D'
call send_byte
br bootrom
@@
-154,3
+158,12
@@
bt_J:
brr r0
tehend:
brr r0
tehend:
+ xor r1, r1, r1
+ ldi r1, 0x41 ; 'A'
+ call send_byte
+ xor r1, r1, r1
+ ldi r1, 0x42 ; 'B'
+ call send_byte
+ xor r1, r1, r1
+ ldi r1, 0x43 ; 'C'
+ call send_byte