49 lines
914 B
ArmAsm
49 lines
914 B
ArmAsm
#define SEG_KCODE 1 // kernel code
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#define SEG_KDATA 2 // kernel data+stack
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#define SEG_KCPU 3 // kernel per-cpu data
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# vectors.S sends all traps here.
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.globl alltraps
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alltraps:
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# Build trap frame.
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pushl %ds
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pushl %es
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pushl %fs
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pushl %gs
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pushal
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# Set up data and per-cpu segments.
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# Can find out KDATA from %ss.
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# Assume that KCPU is KDATA+1.
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movw $(SEG_KDATA<<3), %ax
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movw %ss, %ax
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movw %ax, %ds
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movw %ax, %es
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movw $(SEG_KCPU<<3), %ax
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movw %ax, %fs
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movw %ax, %gs
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# Call trap(tf), where tf=%esp
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pushl %esp
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call trap
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addl $4, %esp
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# Return falls through to trapret...
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.globl trapret
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trapret:
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popal
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popl %gs
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popl %fs
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popl %es
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popl %ds
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addl $0x8, %esp # trapno and errcode
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iret
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# A forked process switches to user mode by calling
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# forkret1(tf), where tf is the trap frame to use.
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.globl forkret1
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forkret1:
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movl 4(%esp), %esp
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jmp trapret
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