55 lines
1.3 KiB
ArmAsm
55 lines
1.3 KiB
ArmAsm
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# uskel runtime and start; include this at the top.
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.section .init
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.global _start
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_start:
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jmp _uskel_start
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.include "include/macros.s"
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.section .bss
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_memory_state:
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cell 0 # bottom of allocation (grows down)
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cell 0 # region start
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cell 0 # region end
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cell 0 # program entry rsp (aka the actual stack)
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.section .text
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_uskel_alloc_basic_mem:
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mov $0x100000, %r15 # desired size
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mov $0x9, %rax # mmap
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mov $0, %rdi # addr = NULL
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mov %r15, %rsi # len = %rcx
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mov $0x3, %rdx # prot = PROT_READ 0x1 | PROT_WRITE 0x2
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mov $0x22, %r10 # flags = MAP_PRIVATE 0x2 | MAP_ANONYMOUS 0x20
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mov $-1, %r8 # fd = -1
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mov $0, %r9 # off = 0
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syscall
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mov $_memory_state, %rdi
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mov %rax, 010(%rdi)
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add %r15, %rax
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mov %rax, (%rdi)
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mov %rax, 020(%rdi)
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retq
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_uskel_start:
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call _uskel_alloc_basic_mem
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# use the stack pointer for easy writing to the heap,
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# but back it up to memory state
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mov $_memory_state, %rdi
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mov %rsp, 030(%rdi)
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mov 0(%rdi), %rsp
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# push a thunk for main
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pushq $0
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pushq $main
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mov $0, %rsi # set continuation to exit
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enter %rsp # run the program
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# Q: are there gonna be functions that have both the argument AND the cont?
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# A: No, stuff is either entered as return-continuation (takes res, cont has to be saved) or as forward call (takes cont)
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# (needs validation)
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