add lab answers

2014-08-20 15:42:20 +08:00
parent d9ec12887b
commit f9773095fe
731 changed files with 92876 additions and 0 deletions
--- a/labcodes_answer/lab8_result/user/libs/initcode.S
+++ b/labcodes_answer/lab8_result/user/libs/initcode.S
@@ -0,0 +1,24 @@
+.text
+.globl _start
+_start:
+    # set ebp for backtrace
+    movl $0x0, %ebp
+
+    # load argc and argv
+    movl (%esp), %ebx
+    lea 0x4(%esp), %ecx
+
+
+    # move down the esp register
+    # since it may cause page fault in backtrace
+    subl $0x20, %esp
+
+    # save argc and argv on stack
+    pushl %ecx
+    pushl %ebx
+
+    # call user-program function
+    call umain
+1:  jmp 1b
+
+