Refactor system_breakpoint_handler
Modifies system_breakpoint_handler so that all fox32 registers are saved on the stack in a predictable order, and they are printed using a loop. Also comments out two seemingly unneccessary additions in the monitor's hex printing functions.
This commit is contained in:
mebibytedraco
parent
bb3d709ad6
commit
b1aa77aa70
493
exception.asm
493
exception.asm
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@ -41,12 +41,14 @@ system_page_fault_handler:
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system_page_fault_str: data.str "Page fault at virtual address r1" data.8 10 data.8 0
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system_page_fault_str: data.str "Page fault at virtual address r1" data.8 10 data.8 0
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; called upon execution of a `brk` instruction
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; called upon execution of a `brk` instruction
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; ensure the stack has at least 256 bytes of free space before triggering this exception!!
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; ensure the stack has at least 128 bytes of free space before triggering this exception!!
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; this code is extremely ugly, but it works :P
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system_breakpoint_handler:
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system_breakpoint_handler:
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add rsp, 4
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add rsp, 4
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; push all registers once to save them
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; push all registers once to save them
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push rfp
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push resp
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push rsp
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push r31
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push r31
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push r30
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push r30
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push r29
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push r29
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@ -80,470 +82,60 @@ system_breakpoint_handler:
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push r1
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push r1
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push r0
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push r0
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; then push all registers again so they can be popped one by one to print to the monitor
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; modify the saved rsp value to reflect the value of rsp before the
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push r31
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; interrupt occured
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push r30
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; resp (4) + rfp (4) + flags (1) + return address (4) = 13 bytes
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push r29
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add [rsp+128], 13
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push r28
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push r27
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push r26
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push r25
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push r24
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push r23
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push r22
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push r21
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push r20
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push r19
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push r18
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push r17
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push r16
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push r15
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push r14
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push r13
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push r12
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push r11
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push r10
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push r9
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push r8
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push r7
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push r6
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push r5
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push r4
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push r3
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push r2
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push r1
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push r0
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; print breakpoint message
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mov r0, system_breakpoint_str
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mov r0, system_breakpoint_str
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call debug_print
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call debug_print
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call print_string_to_monitor
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call print_string_to_monitor
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; r0
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; print the display containing all of the registers
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mov r0, system_breakpoint_r0_str
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; r1 - used to store a pointer to the current string
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; r2 - stores the current address on the stack
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; r3 - loop counter
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mov r1, system_breakpoint_r0_str
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mov r2, rsp
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mov r3, 0
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system_breakpoint_print_loop:
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; print the register label
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mov r0, r1
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call print_string_to_monitor
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call print_string_to_monitor
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pop r0
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; print the register value
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mov r0, [r2]
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call print_hex_word_to_monitor
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call print_hex_word_to_monitor
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; adjust string pointer, stack address, and loop counter
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mov r0, ' '
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add r1, SYSTEM_BREAKPOINT_R_STR_SIZE
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call print_character_to_monitor
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inc r2, 4
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mov r0, '|'
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inc r3
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call print_character_to_monitor
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; decide whether to print a separator or a newline by checking if the loop
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mov r0, ' '
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; counter is a multiple of 4
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call print_character_to_monitor
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mov r0, r3
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and r0, 0x03
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; r1
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ifnz jmp system_breakpoint_print_sep
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mov r0, system_breakpoint_r1_str
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system_breakpoint_print_newline:
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r2
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mov r0, system_breakpoint_r2_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r3
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mov r0, system_breakpoint_r3_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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; ---
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mov r0, 10
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mov r0, 10
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call print_character_to_monitor
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jmp system_breakpoint_print_last_char
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; ---
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system_breakpoint_print_sep:
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; r4
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mov r0, system_breakpoint_r4_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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mov r0, ' '
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call print_character_to_monitor
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call print_character_to_monitor
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mov r0, '|'
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mov r0, '|'
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call print_character_to_monitor
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call print_character_to_monitor
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mov r0, ' '
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mov r0, ' '
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system_breakpoint_print_last_char:
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call print_character_to_monitor
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call print_character_to_monitor
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; loop again if not on last register
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; r5
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cmp r3, 35
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mov r0, system_breakpoint_r5_str
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iflt jmp system_breakpoint_print_loop
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call print_string_to_monitor
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; print rip
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r6
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mov r0, system_breakpoint_r6_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r7
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mov r0, system_breakpoint_r7_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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; ---
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mov r0, 10
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call print_character_to_monitor
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; ---
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; r8
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mov r0, system_breakpoint_r8_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r9
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mov r0, system_breakpoint_r9_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r10
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mov r0, system_breakpoint_r10_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r11
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mov r0, system_breakpoint_r11_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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; ---
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mov r0, 10
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call print_character_to_monitor
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; ---
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; r12
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mov r0, system_breakpoint_r12_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r13
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mov r0, system_breakpoint_r13_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r14
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mov r0, system_breakpoint_r14_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r15
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mov r0, system_breakpoint_r15_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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; ---
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mov r0, 10
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call print_character_to_monitor
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; ---
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; r16
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mov r0, system_breakpoint_r16_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r17
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mov r0, system_breakpoint_r17_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r18
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mov r0, system_breakpoint_r18_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r19
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mov r0, system_breakpoint_r19_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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; ---
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mov r0, 10
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call print_character_to_monitor
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; ---
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; r20
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mov r0, system_breakpoint_r20_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r21
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mov r0, system_breakpoint_r21_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r22
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mov r0, system_breakpoint_r22_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r23
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mov r0, system_breakpoint_r23_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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; ---
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mov r0, 10
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call print_character_to_monitor
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; ---
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; r24
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mov r0, system_breakpoint_r24_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r25
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mov r0, system_breakpoint_r25_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r26
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mov r0, system_breakpoint_r26_str
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call print_string_to_monitor
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pop r0
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call print_hex_word_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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mov r0, '|'
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call print_character_to_monitor
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mov r0, ' '
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call print_character_to_monitor
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; r27
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mov r0, system_breakpoint_r27_str
|
|
||||||
call print_string_to_monitor
|
|
||||||
pop r0
|
|
||||||
call print_hex_word_to_monitor
|
|
||||||
|
|
||||||
; ---
|
|
||||||
mov r0, 10
|
|
||||||
call print_character_to_monitor
|
|
||||||
; ---
|
|
||||||
|
|
||||||
; r28
|
|
||||||
mov r0, system_breakpoint_r28_str
|
|
||||||
call print_string_to_monitor
|
|
||||||
pop r0
|
|
||||||
call print_hex_word_to_monitor
|
|
||||||
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, '|'
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
|
|
||||||
; r29
|
|
||||||
mov r0, system_breakpoint_r29_str
|
|
||||||
call print_string_to_monitor
|
|
||||||
pop r0
|
|
||||||
call print_hex_word_to_monitor
|
|
||||||
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, '|'
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
|
|
||||||
; r30
|
|
||||||
mov r0, system_breakpoint_r30_str
|
|
||||||
call print_string_to_monitor
|
|
||||||
pop r0
|
|
||||||
call print_hex_word_to_monitor
|
|
||||||
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, '|'
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
|
|
||||||
; r31
|
|
||||||
mov r0, system_breakpoint_r31_str
|
|
||||||
call print_string_to_monitor
|
|
||||||
pop r0
|
|
||||||
call print_hex_word_to_monitor
|
|
||||||
|
|
||||||
; ---
|
|
||||||
mov r0, 10
|
|
||||||
call print_character_to_monitor
|
|
||||||
; ---
|
|
||||||
|
|
||||||
; rsp
|
|
||||||
mov r0, system_breakpoint_rsp_str
|
|
||||||
call print_string_to_monitor
|
|
||||||
mov r0, rsp
|
|
||||||
add r0, 133 ; account for the registers pushed above, and for the int calling convention
|
|
||||||
call print_hex_word_to_monitor
|
|
||||||
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, '|'
|
|
||||||
call print_character_to_monitor
|
|
||||||
mov r0, ' '
|
|
||||||
call print_character_to_monitor
|
|
||||||
|
|
||||||
; rip
|
|
||||||
mov r0, system_breakpoint_rip_str
|
mov r0, system_breakpoint_rip_str
|
||||||
call print_string_to_monitor
|
call print_string_to_monitor
|
||||||
mov r0, rsp
|
mov r0, [r2+1]
|
||||||
add r0, 129 ; read instruction pointer from the stack
|
|
||||||
mov r0, [r0]
|
|
||||||
call print_hex_word_to_monitor
|
call print_hex_word_to_monitor
|
||||||
|
|
||||||
; ---
|
|
||||||
mov r0, 10
|
mov r0, 10
|
||||||
call print_character_to_monitor
|
call print_character_to_monitor
|
||||||
; ---
|
|
||||||
|
|
||||||
call invoke_monitor
|
call invoke_monitor
|
||||||
|
|
||||||
|
|
@ -579,8 +171,13 @@ system_breakpoint_handler:
|
||||||
pop r29
|
pop r29
|
||||||
pop r30
|
pop r30
|
||||||
pop r31
|
pop r31
|
||||||
|
; don't restore rsp and resp. not sure whether restoring a potentially
|
||||||
|
; modified resp would break things, but changing rsp definitely would.
|
||||||
|
add rsp, 8
|
||||||
|
pop rfp
|
||||||
reti
|
reti
|
||||||
system_breakpoint_str: data.str "Breakpoint reached!" data.8 10 data.8 0
|
system_breakpoint_str: data.str "Breakpoint reached!" data.8 10 data.8 0
|
||||||
|
const SYSTEM_BREAKPOINT_R_STR_SIZE: 7
|
||||||
system_breakpoint_r0_str: data.strz "r0: "
|
system_breakpoint_r0_str: data.strz "r0: "
|
||||||
system_breakpoint_r1_str: data.strz "r1: "
|
system_breakpoint_r1_str: data.strz "r1: "
|
||||||
system_breakpoint_r2_str: data.strz "r2: "
|
system_breakpoint_r2_str: data.strz "r2: "
|
||||||
|
|
@ -614,4 +211,6 @@ system_breakpoint_r29_str: data.strz "r29: "
|
||||||
system_breakpoint_r30_str: data.strz "r30: "
|
system_breakpoint_r30_str: data.strz "r30: "
|
||||||
system_breakpoint_r31_str: data.strz "r31: "
|
system_breakpoint_r31_str: data.strz "r31: "
|
||||||
system_breakpoint_rsp_str: data.strz "rsp: "
|
system_breakpoint_rsp_str: data.strz "rsp: "
|
||||||
|
system_breakpoint_resp_str: data.strz "resp: "
|
||||||
|
system_breakpoint_rfp_str: data.strz "rfp: "
|
||||||
system_breakpoint_rip_str: data.strz "rip: "
|
system_breakpoint_rip_str: data.strz "rip: "
|
||||||
|
|
|
||||||
|
|
@ -38,7 +38,7 @@ print_hex_word_to_monitor_loop:
|
||||||
add r12, r11
|
add r12, r11
|
||||||
movz.8 r0, [r12]
|
movz.8 r0, [r12]
|
||||||
call print_character_to_monitor
|
call print_character_to_monitor
|
||||||
add r1, r6
|
;add r1, r6
|
||||||
loop print_hex_word_to_monitor_loop
|
loop print_hex_word_to_monitor_loop
|
||||||
|
|
||||||
pop r31
|
pop r31
|
||||||
|
|
@ -67,7 +67,7 @@ print_hex_byte_to_monitor_loop:
|
||||||
add r12, r11
|
add r12, r11
|
||||||
movz.8 r0, [r12]
|
movz.8 r0, [r12]
|
||||||
call print_character_to_monitor
|
call print_character_to_monitor
|
||||||
add r1, r6
|
;add r1, r6
|
||||||
loop print_hex_byte_to_monitor_loop
|
loop print_hex_byte_to_monitor_loop
|
||||||
|
|
||||||
pop r31
|
pop r31
|
||||||
|
|
|
||||||
Loading…
Reference in New Issue
Block a user