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mu/subx/examples/ex12.subx

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4808 - clean up comments in all subx files
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# Example showing mmap syscall.
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# Create a new segment using mmap, save the address, write to it.
#
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# To run (from the subx directory):
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# $ ./subx translate examples/ex12.subx -o examples/ex12
# $ ./subx run examples/ex12
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# You shouldn't get a segmentation fault.
== code
4802 Some automated commenting cleanup. Still needs more careful manual scanning. sed -i 's/^# 1-3/# . 1-3/' *.subx */*.subx sed -i 's/^# op/# . op/' *.subx */*.subx sed -i 's/# vim/# . . vim/' *.subx */*.subx sed -i 's/^ # push args/ # . . push args/' *.subx */*.subx sed -i 's/^ # discard args/ # . . discard args/' *.subx */*.subx sed -i 's/^ # call/ # . . call/' *.subx */*.subx sed -i 's/^ # prolog/ # . prolog/' *.subx */*.subx sed -i 's/^ # epilog/ # . epilog/' *.subx */*.subx sed -i 's/^ # save registers/ # . save registers/' *.subx */*.subx sed -i 's/^ # restore registers/ # . restore registers/' *.subx */*.subx sed -i 's/ operand / register /' *.subx */*.subx
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# instruction effective address register displacement immediate
# . op subop mod rm32 base index scale r32
# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes
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4801 Reindent all SubX code to make some room for the new comment style.
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# syscall(mmap, 0x1000)
bb/copy-to-EBX Mmap-new-segment/imm32
b8/copy-to-EAX 0x5a/imm32/mmap
cd/syscall 0x80/imm8
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4808 - clean up comments in all subx files
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# write to *EAX to check that we have access to the newly-allocated segment
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c7 0/subop/copy 0/mod/direct 0/rm32/EAX . . . . . 0x34/imm32 # copy to *EAX
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4801 Reindent all SubX code to make some room for the new comment style.
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# syscall(exit, EAX)
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89/copy 3/mod/direct 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to EBX
4801 Reindent all SubX code to make some room for the new comment style.
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b8/copy-to-EAX 1/imm32/exit
cd/syscall 0x80/imm8
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== data
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# various constants used here were found in the Linux sources (search for file mman-common.h)
4757 Let's start highlighting all global variables in Red. Assembly programming has a tendency to over-use them. They're a necessary evil, but we should minimize the number of functions that access them.
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Mmap-new-segment: # type mmap_arg_struct
4801 Reindent all SubX code to make some room for the new comment style.
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# addr
00 00 00 00 # null
# len
00 01 00 00 # 0x1000
# protection flags
03 00 00 00 # PROT_READ | PROT_WRITE
# sharing flags
22 00 00 00 # MAP_PRIVATE | MAP_ANONYMOUS
# fd
ff ff ff ff # -1 since MAP_ANONYMOUS is specified
# offset
00 00 00 00 # 0 since MAP_ANONYMOUS is specified
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4802 Some automated commenting cleanup. Still needs more careful manual scanning. sed -i 's/^# 1-3/# . 1-3/' *.subx */*.subx sed -i 's/^# op/# . op/' *.subx */*.subx sed -i 's/# vim/# . . vim/' *.subx */*.subx sed -i 's/^ # push args/ # . . push args/' *.subx */*.subx sed -i 's/^ # discard args/ # . . discard args/' *.subx */*.subx sed -i 's/^ # call/ # . . call/' *.subx */*.subx sed -i 's/^ # prolog/ # . prolog/' *.subx */*.subx sed -i 's/^ # epilog/ # . epilog/' *.subx */*.subx sed -i 's/^ # save registers/ # . save registers/' *.subx */*.subx sed -i 's/^ # restore registers/ # . restore registers/' *.subx */*.subx sed -i 's/ operand / register /' *.subx */*.subx
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# . . vim:nowrap:textwidth=0