fix ask_name STDIO

1 files changed, 18 insertions, 50 deletions

diff --git a/examples/ask_name.subv b/examples/ask_name.subv
index dfd5a7a..4be18eb 100644
--- a/examples/ask_name.subv
+++ b/examples/ask_name.subv
@@ -7,7 +7,7 @@
 # $ ./subv.sh examples/ask_.subv >examples/ask_.elf
 # $ cat 2>dev/null | ./qemu.sh examples/ask_.elf
 #   What's your name?
-# > Sol
+#   > Sol
 #   Hello Sol, nice to meet you!
 
 == code 0x80400000
@@ -16,13 +16,16 @@
   # 63/branch 1/subop/!= 5/rs/t0 0/rs/x0 0/off13
 
 main:
-  6f/jal 1/rd/ra init/off21
-
   # print HELLO_WHATSURNAME
   37/lui a/rd/a0 HELLO_WHATSURNAME/imm20hi
   13/opi a/rd/a0 0/subop/add a/rs/a0 HELLO_WHATSURNAME/imm12lo
   6f/jal 1/rd/ra print/off21
 
+  # read in Name
+  37/lui a/rd/a0 PROMPT/imm20hi
+  13/opi a/rd/a0 0/subop/add a/rs/a0 PROMPT/imm12lo
+  6f/jal 1/rd/ra print/off21
+
   37/lui a/rd/a0 Name/imm20hi
   13/opi a/rd/a0 0/subop/add a/rs/a0 Name/imm12lo
   6f/jal 1/rd/ra read/off21
@@ -53,48 +56,6 @@ exit:
   # ECALL
   73/system 0/subop/priv 0/funct12/ecall
 
-init:
-# initialize UART0
-  # load 0x10000000 (UART0) into t0
-  37/lui 5/rd/t0 10000/imm20
-
-  # disable interrupts
-  23/store 0/width/b 5/rs/t0 1/off12 0/rs/x0
-
-  # enable DLAB
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 80/imm12
-  23/store 0/width/b 5/rs/t0 3/off12 6/rs/t1
-
-  # max speed = 38400bps
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 3/imm12
-  23/store 0/width/b 5/rs/t0 0/off12 6/rs/t1
-  23/store 0/width/b 5/rs/t0 1/off12 0/rs/x0
-
-  # disable DLAB
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 3/imm12
-  23/store 0/width/b 5/rs/t0 3/off12 6/rs/t1
-
-  # enable fifo, clear, watermark=14b
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 c7/imm12
-  23/store 0/width/b 5/rs/t0 2/off12 6/rs/t1
-
-  # set dtr, srs, aux2
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 b/imm12
-  23/store 0/width/b 5/rs/t0 4/off12 6/rs/t1
-
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 1/imm12
-  23/store 0/width/b 5/rs/t0 1/off12 6/rs/t1
-
-  # return
-  67/jalr 0/subop 0/rd/x0 1/rs/ra 0/off12
-
-old:
-  # set "data terminal ready" and "request to send" bits in MCR
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 3/imm12
-  23/store 0/width/b 5/rs/t0 4/off12 6/rs/t1
-  # return
-  67/jalr 0/subop 0/rd/x0 1/rs/ra 0/off12
-
 print:
 # print a C-string from a0
   # load 0x10000000 (UART0) into t0
@@ -123,8 +84,8 @@ read:
 # read a C-string into a0
   # load 0x10000000 (UART0) into t0
   37/lui 5/rd/t0 10000/imm20
-  # load 0x0a (\n) into t1
-  13/opi 6/rd/t1 0/subop/add 0/rs/x0 0a/imm12
+  # load 0x0d (\r) into t1
+  13/opi 6/rd/t1 0/subop/add 0/rs/x0 0d/imm12
 
 read:loop:
   # spin if FIFO is empty (data_ready = UART+5 & 1)
@@ -135,13 +96,17 @@ read:loop:
   03/load 7/rd/t2 4/width/bu 5/rs/t0 0/imm12
   # break loop if newline (t2 == t1)
   63/branch 0/subop/== 7/rs/t2 6/rs/t1 read:break/off13
-  # store char from t1 at [a0]
-  23/store 0/width/b a/rs/a0 7/rs/t2 0/off12
+  # echo and store char from t2
+  23/store 0/width/b 5/rs/t0 0/off12 7/rs/t2
+  23/store 0/width/b a/rs/a0 0/off12 7/rs/t2
   # increment a0
   13/opi a/rd/a0 0/subop/add a/rs/a0 1/imm12
   # jump back up
   6f/jal 0/rd/x0 read:loop/off21
 read:break:
+  # echo \n
+  13/opi 7/rd/t2 0/subop/add 0/rs/x0 0a/imm12
+  23/store 0/width/b 5/rs/t0 0/off12 7/rs/t2
   # return
   67/jalr 0/rd/x0 0/subop 1/rs/ra 0/off12
 
@@ -156,5 +121,8 @@ HELLO_:
 NICETOMEETU:
   # ", nice to meet you!\n\0"
   2c/8 20/8 6e/8 69/8 63/8 65/8 20/8 74/8 6f/8 20/8 6d/8 65/8 65/8 74/8 20/8 79/8 6f/8 75/8 21/8 0a/8 00/8
+PROMPT:
+  # "> "
+  3e/8 20/8 00/8
 Name:
-  00/8
+  0/256