187 lines
3.8 KiB
ArmAsm
187 lines
3.8 KiB
ArmAsm
.align 1
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.thumb
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start:
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@ Store R0 to the stack
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push {r0}
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LDR R0, addr_debugger_storage
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stmia r0, {r0-r7}
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@ Also store r0 by using r1
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ldr r1, addr_debugger_storage
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pop {r0}
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str r0, [r1, #0]
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# Keep using r0
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LDR R0, addr_debugger_storage
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@ Store R8 to R15, not available directly in thumb mode
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mov r1, r8
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str r1, [r0, #0x20]
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mov r1, r9
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str r1, [r0, #0x24]
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mov r1, r10
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str r1, [r0, #0x28]
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mov r1, r11
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str r1, [r0, #0x2c]
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mov r1, r12 //ip scratch
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str r1, [r0, #0x30]
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mov r1, sp //sp
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str r1, [r0, #0x34]
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mov r1, lr //lr
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str r1, [r0, #0x38]
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mov r1, pc //pc
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str r1, [r0, #0x3c]
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// set debugger stack (r13 sp, r14 lr, r15 pc)
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ldr r0, addr_debugger_stack
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mov sp, r0
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// Compare to see if we need to jump into the debugger or need to continue the 'normal' execution flow
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// Default is jump in debugger
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// CNT_EXEC 0x7f0
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ldr r1, addr_debugger_storage
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ldr r0, =0x700
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add r0, #0xf0
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add r0, r0, r1
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CMP r0, #0x77
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beq start_normal
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@ TODO, use r8, how can I clear it
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ldr r2, addr_debugger_main
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mov r12, r2
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bx r12
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// Continue 'normal' execution flow
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start_normal:
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BL sync_processor_state
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// Restore LR, TODO
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@ LDR LR, [r1, #240]
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@ // Restore the stack pointer
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@ LDR R0, [r1, #248]
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@ MOV SP, R0
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// Also restore X0
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LDR R0, [r1, #0]
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// 0x7ec DBG_JUMP_TO
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@ LDR r1, [r1, #0x7ec]
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@ bx r1
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.text
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.global restore_and_jump
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restore_and_jump:
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// Restores all registers except for LR and SP
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BL sync_processor_state
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// restore SP, LR
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ldr r0, addr_debugger_storage
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ldr r1, [r0, #0x34]
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mov sp, r1 //SP
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ldr r1, [r0, #0x38]
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mov lr, r1 //LR
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@ Load JUMP_ADDR 0x7fc into r12
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ldr r0, addr_debugger_storage
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ldr r1, =0x7fc
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add r1, r1, r0
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ldr r1, [r1] @ JUMP_ADDR
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mov r12, r1
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// Restore r0 and r1
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ldr r0, addr_debugger_storage
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ldr r1, [r0, #4]
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ldr r0, [r0]
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@ At this point everything is restored except for r12, which contains the jump address
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bx r12
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.text
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.global debugger_sync_special_regs
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debugger_sync_special_regs:
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@ mov r4, #0x77
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// TODO, what special regs??
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bx LR
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.text
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.global dump_special_regs
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dump_special_regs:
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// TODO, what special regs??
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bx LR
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.text
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.global debugger_dump_special_regs
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debugger_dump_special_regs:
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BL dump_special_regs
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B debugger_main
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.text
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.global sync_processor_state
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sync_processor_state:
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@ Syncs general purpose registers back to the cpu and branches to the LR
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@ Load r8-r12
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ldr r0, addr_debugger_storage
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ldr r1, [r0, #0x20]
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mov r8, r1
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ldr r1, [r0, #0x24]
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mov r9, r1
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ldr r1, [r0, #0x28]
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mov r10, r1
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ldr r1, [r0, #0x2c]
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mov r11, r1
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ldr r1, [r0, #0x30]
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mov r12, r1
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@ Not restoring SP, LR and PC. Left here as reference
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@ ldr r1, [r0, #0x34]
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@ mov r13, r1 //sp
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@ ldr r1, [r0, #0x38]
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@ mov r14, r1 //lr
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@ ldr r1, [r0, #0x3c]
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@ mov r15, r1 //pc
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@ load r0-r7
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ldr r0, addr_debugger_storage
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ldmia r0, {r0-r7}
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bx lr
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.text
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.global restore_and_return
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restore_and_return:
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B sync_processor_state
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// restore SP, LR
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ldr r0, addr_debugger_storage
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ldr r1, [r0, #0x30]
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mov r12, r1 //IP
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ldr r1, [r0, #0x34]
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mov sp, r1 //SP
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ldr r1, [r0, #0x38]
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mov lr, r1 //LR
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// Restore r0 and r1
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@ ldr r0, addr_debugger_storage
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ldr r1, [r0, #4]
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ldr r0, [r0]
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@ At this point everything is restored including the LR. Return to it
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BX LR
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.text
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.global sync_debugger
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sync_debugger:
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BL sync_processor_state
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b debugger_main
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.align 4
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addr_debugger_storage: .word debugger_storage
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addr_debugger_stack: .word debugger_stack
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addr_debugger_main: .word debugger_main |