valter/dosbox-staging
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Model irq 0 stack layout in a more compatible way. Fixes M.U.L.E. booter. (ripsaw)

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3781
This commit is contained in:
Peter Veenstra 2012-06-08 14:23:55 +00:00
parent 98d04262ec
commit 498e583251
2 changed files with 18 additions and 17 deletions
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29
src/cpu/callback.cpp
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@ -218,24 +218,25 @@ Bitu CALLBACK_SetupExtra(Bitu callback, Bitu type, PhysPt physAddress, bool use_
phys_writeb(physAddress+0x06,(Bit8u)0xcf); //An IRET Instruction
return (use_cb?0x0b:0x07);
case CB_IRQ0: // timer int8
phys_writeb(physAddress+0x00,(Bit8u)0xFB); //STI
if (use_cb) {
phys_writeb(physAddress+0x00,(Bit8u)0xFE); //GRP 4
phys_writeb(physAddress+0x01,(Bit8u)0x38); //Extra Callback instruction
phys_writew(physAddress+0x02,(Bit16u)callback); //The immediate word
phys_writeb(physAddress+0x01,(Bit8u)0xFE); //GRP 4
phys_writeb(physAddress+0x02,(Bit8u)0x38); //Extra Callback instruction
phys_writew(physAddress+0x03,(Bit16u)callback); //The immediate word
physAddress+=4;
}
phys_writeb(physAddress+0x00,(Bit8u)0x50); // push ax
phys_writeb(physAddress+0x01,(Bit8u)0x52); // push dx
phys_writeb(physAddress+0x02,(Bit8u)0x1e); // push ds
phys_writew(physAddress+0x03,(Bit16u)0x1ccd); // int 1c
phys_writeb(physAddress+0x05,(Bit8u)0xfa); // cli
phys_writeb(physAddress+0x06,(Bit8u)0x1f); // pop ds
phys_writeb(physAddress+0x07,(Bit8u)0x5a); // pop dx
phys_writew(physAddress+0x08,(Bit16u)0x20b0); // mov al, 0x20
phys_writew(physAddress+0x0a,(Bit16u)0x20e6); // out 0x20, al
phys_writeb(physAddress+0x01,(Bit8u)0x1e); // push ds
phys_writeb(physAddress+0x02,(Bit8u)0x50); // push ax
phys_writeb(physAddress+0x03,(Bit8u)0x52); // push dx
phys_writew(physAddress+0x04,(Bit16u)0x1ccd); // int 1c
phys_writeb(physAddress+0x06,(Bit8u)0xfa); // cli
phys_writew(physAddress+0x07,(Bit16u)0x20b0); // mov al, 0x20
phys_writew(physAddress+0x09,(Bit16u)0x20e6); // out 0x20, al
phys_writeb(physAddress+0x0b,(Bit8u)0x5a); // pop dx
phys_writeb(physAddress+0x0c,(Bit8u)0x58); // pop ax
phys_writeb(physAddress+0x0d,(Bit8u)0xcf); //An IRET Instruction
return (use_cb?0x12:0x0e);
phys_writeb(physAddress+0x0d,(Bit8u)0x1f); // pop ds
phys_writeb(physAddress+0x0e,(Bit8u)0xcf); //An IRET Instruction
return (use_cb?0x13:0x0f);
case CB_IRQ1: // keyboard int9
phys_writeb(physAddress+0x00,(Bit8u)0x50); // push ax
phys_writew(physAddress+0x01,(Bit16u)0x60e4); // in al, 0x60

6
src/ints/bios.cpp
View file

@ -997,14 +997,14 @@ public:
CALLBACK_Setup(call_irq0,INT8_Handler,CB_IRQ0,Real2Phys(BIOS_DEFAULT_IRQ0_LOCATION),"IRQ 0 Clock");
RealSetVec(0x08,BIOS_DEFAULT_IRQ0_LOCATION);
// pseudocode for CB_IRQ0:
// sti
// callback INT8_Handler
// push ax,dx,ds
// push ds,ax,dx
// int 0x1c
// cli
// pop ds,dx
// mov al, 0x20
// out 0x20, al
// pop ax
// pop dx,ax,ds
// iret
mem_writed(BIOS_TIMER,0); //Calculate the correct time