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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | /* Project: OSLib |
| 2 | * Description: The OS Construction Kit |
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| 3 | * Date: 1.6.2000 |
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| 4 | * Idea by: Luca Abeni & Gerardo Lamastra |
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| 5 | * |
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| 6 | * OSLib is an SO project aimed at developing a common, easy-to-use |
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| 7 | * low-level infrastructure for developing OS kernels and Embedded |
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| 8 | * Applications; it partially derives from the HARTIK project but it |
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| 9 | * currently is independently developed. |
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| 10 | * |
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| 11 | * OSLib is distributed under GPL License, and some of its code has |
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| 12 | * been derived from the Linux kernel source; also some important |
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| 13 | * ideas come from studying the DJGPP go32 extender. |
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| 14 | * |
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| 15 | * We acknowledge the Linux Community, Free Software Foundation, |
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| 16 | * D.J. Delorie and all the other developers who believe in the |
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| 17 | * freedom of software and ideas. |
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| 18 | * |
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| 19 | * For legalese, check out the included GPL license. |
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| 20 | */ |
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| 21 | |||
| 22 | /* Safe abort routine & timer asm handler */ |
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| 23 | |||
| 24 | .title "VmCx32a.S" |
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| 25 | |||
| 26 | #include <ll/i386/sel.h> |
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| 27 | #include <ll/i386/linkage.h> |
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| 28 | #include <ll/i386/defs.h> |
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| 29 | |||
| 30 | #include <ll/sys/ll/exc.h> |
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| 31 | |||
| 32 | .data |
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| 33 | |||
| 34 | ASMFILE(Context) |
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| 35 | |||
| 36 | .extern JmpSel |
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| 37 | .extern JmpZone |
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| 38 | .globl SYMBOL_NAME(ll_clock) |
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| 39 | .globl SYMBOL_NAME(SafeStack) |
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| 40 | |||
| 41 | /* Used as JMP entry point to check if a real */ |
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| 42 | /* context switch is necessary */ |
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| 43 | |||
| 44 | SYMBOL_NAME_LABEL(ll_clock) .int 0 |
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| 45 | |||
| 46 | /* Safe stack area for aborts */ |
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| 47 | .space 4096,0 |
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| 48 | SYMBOL_NAME_LABEL(SafeStack) |
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| 49 | |||
| 50 | .extern SYMBOL_NAME(periodic_wake_up) |
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| 51 | .extern SYMBOL_NAME(oneshot_wake_up) |
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| 52 | .extern SYMBOL_NAME(act_int) |
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| 53 | .extern SYMBOL_NAME(abort_tail) |
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| 54 | |||
| 55 | .text |
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| 56 | .globl SYMBOL_NAME(ll_timer) |
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| 57 | .globl SYMBOL_NAME(ll_abort) |
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| 58 | |||
| 59 | SYMBOL_NAME_LABEL(ll_abort) |
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| 60 | /* As we are terminating we cannnot handle */ |
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| 61 | /* any other interrupt! */ |
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| 62 | cli |
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| 63 | /* Get argument */ |
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| 64 | movl 4(%esp),%eax |
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| 65 | /* Switch to safe stack */ |
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| 66 | movl $(SYMBOL_NAME(SafeStack)),%esp |
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| 67 | /* Push argument */ |
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| 68 | pushl %eax |
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| 69 | /* Call sys_abort(code) */ |
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| 70 | call SYMBOL_NAME(abort_tail) |
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| 71 | |||
| 72 | /* This is the timer handler; it reloads for safety the DS register; this */ |
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| 73 | /* prevents from mess when timer interrupts linear access to memory (not in */ |
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| 74 | /* ELF address space); then EOI is sent in order to detect timer overrun */ |
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| 75 | /* The high level kernel procedure wake_up() is called to perform the */ |
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| 76 | /* preeption at higher level (process descriptos); the resulting context */ |
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| 77 | /* if different from the old one is used to trigger the task activation. */ |
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| 78 | |||
| 79 | SYMBOL_NAME_LABEL(ll_timer) |
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| 80 | pushal |
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| 81 | pushw %ds |
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| 82 | pushw %es |
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| 83 | pushw %fs |
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| 84 | pushw %gs |
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| 85 | |||
| 86 | movw $(X_FLATDATA_SEL),%ax |
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| 87 | movw %ax,%ds |
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| 88 | movw %ax,%es |
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| 89 | |||
| 90 | /* Send EOI to master PIC */ |
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| 91 | /* to perform later the overrun test */ |
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| 92 | movb $0x20,%al |
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| 93 | movl $0x20,%edx |
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| 94 | outb %al,%dx |
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| 95 | |||
| 96 | /* Call wake_up(actual_context) */ |
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| 97 | |||
| 98 | cld |
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| 99 | movl SYMBOL_NAME(ll_clock),%eax |
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| 100 | incl %eax |
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| 101 | movl %eax,SYMBOL_NAME(ll_clock) |
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| 102 | |||
| 103 | xorl %eax,%eax |
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| 104 | #if 0 |
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| 105 | strw %ax |
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| 106 | pushl %eax |
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| 107 | call SYMBOL_NAME(wake_up) |
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| 108 | addl $4,%esp |
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| 109 | pushl %eax /* Save result on stack */ |
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| 110 | |||
| 111 | #else |
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| 112 | movl SYMBOL_NAME(timermode), %eax |
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| 113 | cmpl $1, %eax |
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| 114 | je oneshot |
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| 115 | call SYMBOL_NAME(periodic_wake_up) |
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| 116 | jmp goon |
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| 117 | oneshot: call SYMBOL_NAME(oneshot_wake_up) |
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| 118 | goon: |
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| 119 | #endif |
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| 120 | /* This is the overrun test */ |
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| 121 | /* Do it after sending EOI to master PIC */ |
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| 122 | |||
| 123 | movb $0x0A,%al |
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| 124 | movl $0x020,%edx |
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| 125 | outb %al,%dx |
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| 126 | inb %dx,%al |
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| 127 | testb $1,%al |
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| 128 | jz Timer_OK |
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| 129 | movl $(CLOCK_OVERRUN),%eax |
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| 130 | pushl %eax |
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| 131 | call SYMBOL_NAME(ll_abort) |
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| 132 | |||
| 133 | #ifdef __VIRCSW__ |
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| 134 | Timer_OK: |
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| 135 | |||
| 136 | movw SYMBOL_NAME(currCtx), %ax |
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| 137 | cmpw %ax,JmpSel |
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| 138 | je NoPreempt2 |
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| 139 | movw %ax,JmpSel |
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| 140 | ljmp JmpZone /* DISPATCH! */ |
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| 141 | #else |
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| 142 | Timer_OK: |
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| 143 | #endif |
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| 144 | NoPreempt2: |
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| 145 | popw %gs |
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| 146 | popw %fs |
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| 147 | popw %es |
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| 148 | popw %ds |
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| 149 | popal |
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| 150 | iret |