chap-05: Reindex older demos

Signed-off-by: Razvan Deaconescu <[email protected]>

curs/chap-05-ihs/05-hello-world/README.md

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+# chap-03-demo
+
+1. Demo gdb
+- make
+- gdb hello
+- Comands: b main, r, n
+- set $eax = 0xffffffff
+- set $eip = main
+
+2. Demo gdb
+ step through hello.asm to inspect the changes to the following registers:
+  * EAX, AX, AH, AL
+  * EFLAGS
+  * EIP
+Note: Instructions to whatch are: MOV, ADD, JMP
+
+3. Demo Inspect ~/.gdbinit 
+- less ~/.gdbinit 
+
+cleanup: 
+set disassembly-flavor intel
+set history save on
+
+
+

curs/chap-05-ihs/06-dandamudi/ijump.sasm.asm

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+	;; adaptat cu macrourile SASM - ușor diferite !
+	
+;Sample indirect jump example    IJUMP.ASM
+;
+;        Objective: To demonstrate the use of indirect jump.
+;            Input: Requests a digit character from the user.
+;           Output: Appropriate class selection message.
+%include "io.inc"
+
+section .data
+jump_table  dd  code_for_0   ; indirect jump pointer table
+            dd  code_for_1
+            dd  code_for_2
+            dd  default_code ; default code for digits 3-9
+            dd  default_code
+            dd  default_code
+            dd  default_code
+            dd  default_code
+            dd  default_code
+            dd  default_code
+
+prompt_msg  db  "Type a digit: ",0
+msg_0       db  "Economy class selected.",0
+msg_1       db  "Business class selected.",0
+msg_2       db  "First class selected.",0
+msg_default db  "Not a valid code!",0
+msg_nodigit db  "Not a digit! Try again.",0
+key         db 0
+
+section .text
+global main
+main:
+    mov ebp, esp; for correct debugging         
+read_again:
+        PRINT_STRING   prompt_msg    ; request a digit
+        sub      EAX,EAX       ; EAX = 0
+        GET_CHAR key
+        mov      AL, [key]            ; read input digit and
+        cmp      AL,'0'        ; check to see if it is a digit
+        jb       not_digit
+        cmp      AL,'9'
+        ja       not_digit
+        ; if digit, proceed
+        sub      AL,'0'        ; convert to numeric equivalent
+        mov      ESI,EAX       ; ESI is index into jump table
+        add      ESI,ESI       ; ESI = ESI * 4
+        add      ESI,ESI
+        jmp      [jump_table+ESI] ; indirect jump based on ESI
+test_termination:
+        cmp      AL,2
+        ja       done
+        jmp      read_again 
+code_for_0:
+        PRINT_STRING   msg_0
+        NEWLINE
+        jmp      test_termination
+code_for_1:
+        PRINT_STRING   msg_1
+        NEWLINE
+        jmp      test_termination
+code_for_2:
+        PRINT_STRING   msg_2
+        NEWLINE
+        jmp      test_termination
+default_code:
+        PRINT_STRING   msg_default
+        NEWLINE
+        jmp      test_termination
+
+not_digit:
+        PRINT_STRING   msg_nodigit
+        NEWLINE
+        jmp      read_again
+done:
+	mov 	eax, 1   	
+	mov 	ebx, 0
+	int     0x80		; exit(0)
+