Mu - subx/053new-segment.subx

From 6e1eeeebfb453fa7c871869c19375ce60fbd7413 Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Sat, 27 Jul 2019 16:01:55 -0700 Subject: 5485 - promote SubX to top-level --- html/subx/053new-segment.subx.html | 154 ------------------------------------- 1 file changed, 154 deletions(-) delete mode 100644 html/subx/053new-segment.subx.html (limited to 'html/subx/053new-segment.subx.html') diff --git a/html/subx/053new-segment.subx.html b/html/subx/053new-segment.subx.html deleted file mode 100644 index cab22dc6..00000000 --- a/html/subx/053new-segment.subx.html +++ /dev/null @@ -1,154 +0,0 @@ - - - - -Mu - subx/053new-segment.subx - - - - - - - - - - -https://github.com/akkartik/mu/blob/master/subx/053new-segment.subx -

- 1 # Create a new segment (pool of memory for allocating chunks from) in the form
- 2 # of an *allocation descriptor* that can be passed to the memory allocator
- 3 # (defined in a later layer).
- 4 #
- 5 # Currently an allocation descriptor consists of just the bounds of the pool of
- 6 # available memory:
- 7 #
- 8 #   curr : address
- 9 #   end : address
-10 #
-11 # This isn't enough information to reclaim individual allocations. We can't
-12 # support arbitrary reclamation yet.
-13 
-14 == code
-15 #   instruction                     effective address                                                   register    displacement    immediate
-16 # . op          subop               mod             rm32          base        index         scale       r32
-17 # . 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
-18 
-19 Entry:   # manual test
-20     # var ad/ECX : (address allocation-descriptor) = {0, 0}
-21     68/push  0/imm32/limit
-22     68/push  0/imm32/curr
-23     89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
-24     # new-segment(0x1000, ad)
-25     # . . push args
-26     51/push-ECX
-27     68/push  0x1000/imm32
-28     # . . call
-29     e8/call  new-segment/disp32
-30     # . . discard args
-31     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-32     # EAX = ad->curr
-33     8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy *ECX to EAX
-34     # write to *EAX to check that we have access to the newly-allocated segment
-35     c7          0/subop/copy        0/mod/direct    0/rm32/EAX    .           .             .           .           .               0x34/imm32        # copy to *EAX
-36     # syscall(exit, EAX)
-37     89/copy                         3/mod/direct    3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to EBX
-38     b8/copy-to-EAX  1/imm32/exit
-39     cd/syscall  0x80/imm8
-40 
-41 new-segment:  # len : int, ad : (address allocation-descriptor)
-42     # . prolog
-43     55/push-EBP
-44     89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-45     # . save registers
-46     50/push-EAX
-47     53/push-EBX
-48     # copy len to _mmap-new-segment->len
-49     8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   8/disp8         .                 # copy *(EBP+8) to EAX
-50     89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/EAX   _mmap-new-segment:len/disp32      # copy EAX to *_mmap-new-segment:len
-51     # mmap(_mmap-new-segment)
-52     bb/copy-to-EBX  _mmap-new-segment/imm32
-53     b8/copy-to-EAX  0x5a/imm32/mmap
-54     cd/syscall  0x80/imm8
-55     # copy {EAX, EAX+len} to *ad
-56     # . EBX = ad
-57     8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           3/r32/EBX   0xc/disp8       .                 # copy *(EBP+12) to EBX
-58     # . *EBX = EAX
-59     89/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to *EBX
-60     # . *(EBX+4) = EAX+len
-61     03/add                          1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   8/disp8         .                 # add *(EBP+8) to EAX
-62     89/copy                         1/mod/*+disp8   3/rm32/EBX    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(EBX+4)
-63 $new-segment:end:
-64     # . restore registers
-65     5b/pop-to-EBX
-66     58/pop-to-EAX
-67     # . epilog
-68     89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
-69     5d/pop-to-EBP
-70     c3/return
-71 
-72 == data
-73 
-74 # various constants used here were found in the Linux sources (search for file mman-common.h)
-75 _mmap-new-segment:  # type mmap_arg_struct
-76     # addr
-77     0/imm32
-78 _mmap-new-segment:len:
-79     # len
-80     0/imm32
-81     # protection flags
-82     3/imm32  # PROT_READ | PROT_WRITE
-83     # sharing flags
-84     0x22/imm32  # MAP_PRIVATE | MAP_ANONYMOUS
-85     # fd
-86     -1/imm32  # since MAP_ANONYMOUS is specified
-87     # offset
-88     0/imm32  # since MAP_ANONYMOUS is specified
-89 
-90 # . . vim:nowrap:textwidth=0
-

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