system comments

2016-03-03 02:03:09 -05:00
parent d33ce4c69f
commit df75edde3c
6 changed files with 141 additions and 115 deletions
@@ -255,29 +255,29 @@ pget: 0
 t = t+3

 iwrite: 0
-   dac 9f+t
-   lac iwrite
+   dac 9f+t				" save arg in t0
+   lac iwrite				" load return address

 "** 01-s1.pdf page 38

-   dac iread
+   dac iread				" save as iread return addr
   lac cskp
-   dac iwrite
+   dac iwrite				" set our return addr to "cskp"
   jmp 1f

 iread: 0
   dac 9f+t
-   lac cnop
+   lac cnop				" set iwrite return to "cnop"
   dac iwrite
 1:
   -1
-   tad iread i
-   dac 10
+   tad iread i				" get word before return addr
+   dac 10				" store in index 8 & 9
   dac 11
-   isz iread
-   lac iread i
-   dac 9f+t+1
-   isz iread
+   isz iread				" increment return addr
+   lac iread i				" load word
+   dac 9f+t+1				" save in t1
+   isz iread				" increment return addr
   lac o70000
   xct iwrite
   lac i.size