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https://github.com/KevinMidboe/linguist.git
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92 lines
1.3 KiB
Plaintext
92 lines
1.3 KiB
Plaintext
# output(): Hello, world.\n
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# mach(): all
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# Emit hello world while switching back and forth between arm/thumb.
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# ??? Unfinished
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.macro invalid
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# This is "undefined" but it's not properly decoded yet.
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.word 0x07ffffff
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# This is stc which isn't recognized yet.
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stc 0,cr0,[r0]
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.endm
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.global _start
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_start:
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# Run some simple insns to confirm the engine is at least working.
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nop
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# Skip over output text.
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bl skip_output
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hello_text:
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.asciz "Hello, world.\n"
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.p2align 2
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skip_output:
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# Prime loop.
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mov r4, r14
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output_next:
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# Switch arm->thumb to output next chacter.
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# At this point r4 must point to the next character to output.
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adr r0, into_thumb + 1
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bx r0
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into_thumb:
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.thumb
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# Output a character.
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mov r0,#3 @ writec angel call
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mov r1,r4
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swi 0xab @ ??? Confirm number.
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# Switch thumb->arm.
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adr r5, back_to_arm
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bx r5
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.p2align 2
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back_to_arm:
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.arm
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# Load next character, see if done.
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add r4,r4,#1
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sub r3,r3,r3
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ldrb r5,[r4,r3]
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teq r5,#0
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beq done
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# Output a character (in arm mode).
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mov r0,#3
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mov r1,r4
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swi #0x123456
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# Load next character, see if done.
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add r4,r4,#1
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sub r3,r3,r3
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ldrb r5,[r4,r3]
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teq r5,#0
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bne output_next
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done:
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mov r0,#0x18
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ldr r1,exit_code
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swi #0x123456
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# If that fails, try to die with an invalid insn.
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invalid
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exit_code:
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.word 0x20026
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