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/* Project: OSLib* Description: The OS Construction Kit* Date: 1.6.2000* Idea by: Luca Abeni & Gerardo Lamastra** OSLib is an SO project aimed at developing a common, easy-to-use* low-level infrastructure for developing OS kernels and Embedded* Applications; it partially derives from the HARTIK project but it* currently is independently developed.** OSLib is distributed under GPL License, and some of its code has* been derived from the Linux kernel source; also some important* ideas come from studying the DJGPP go32 extender.** We acknowledge the Linux Community, Free Software Foundation,* D.J. Delorie and all the other developers who believe in the* freedom of software and ideas.** For legalese, check out the included GPL license.*//* Exc/IRQ handlers (asm part) *//* TODO: Unify the Exc/Int Mechanism... */#include <ll/i386/sel.h>#include <ll/i386/linkage.h>#include <ll/i386/int.h>#include <ll/i386/defs.h>.extern SYMBOL_NAME(GDT_base).dataASMFILE(Exc).globl SYMBOL_NAME(ll_irq_table)SYMBOL_NAME_LABEL(ll_irq_table) .space 1024, 0.text.extern SYMBOL_NAME(ll_exc_hook).extern SYMBOL_NAME(ll_FPU_hook).globl SYMBOL_NAME(h13_bis).globl SYMBOL_NAME(exc7)/* These are the hardware handlers; they all jump to ll_handler setting *//* the interrupt number into EAX & save the registers on stack */INT(0)INT(1)INT(2)INT(3)INT(4)INT(5)INT(6)INT(8)INT(9)INT(10)INT(11)INT(12)INT(13)INT(14)INT(15)INT(16)INT(17)INT(18)INT(19)INT(20)INT(21)INT(22)INT(23)INT(24)INT(25)INT(26)INT(27)INT(28)INT(29)INT(30)INT(31)INT(32)INT(33)INT(34)INT(35)INT(36)INT(37)INT(38)INT(39)INT(40)INT(41)INT(42)INT(43)INT(44)INT(45)INT(46)INT(47)INT(48)INT(49)INT(50)INT(51)INT(52)INT(53)INT(54)INT(55)INT(56)INT(57)INT(58)INT(59)INT(60)INT(61)INT(62)INT(63)/* Master PIC... (int 0x40, see ll/i386/pic.h)*/INT_1(64)INT_1(65)INT_1(66)INT_1(67)INT_1(68)INT_1(69)INT_1(70)INT_1(71)INT(72)INT(73)INT(74)INT(75)INT(76)INT(77)INT(78)INT(79)INT(80)INT(81)INT(82)INT(83)INT(84)INT(85)INT(86)INT(87)INT(88)INT(89)INT(90)INT(91)INT(92)INT(93)INT(94)INT(95)INT(96)INT(97)INT(98)INT(99)INT(100)INT(101)INT(102)INT(103)INT(104)INT(105)INT(106)INT(107)INT(108)INT(109)INT(110)INT(111)/* Slave PIC... (int 0x70, see ll/i386/pic.h)*/INT_2(112)INT_2(113)INT_2(114)INT_2(115)INT_2(116)INT_2(117)INT_2(118)INT_2(119)INT(120)INT(121)INT(122)INT(123)INT(124)INT(125)INT(126)INT(127)INT(128)INT(129)INT(130)INT(131)INT(132)INT(133)INT(134)INT(135)INT(136)INT(137)INT(138)INT(139)INT(140)INT(141)INT(142)INT(143)INT(144)INT(145)INT(146)INT(147)INT(148)INT(149)INT(150)INT(151)INT(152)INT(153)INT(154)INT(155)INT(156)INT(157)INT(158)INT(159)INT(160)INT(161)INT(162)INT(163)INT(164)INT(165)INT(166)INT(167)INT(168)INT(169)INT(170)INT(171)INT(172)INT(173)INT(174)INT(175)INT(176)INT(177)INT(178)INT(179)INT(180)INT(181)INT(182)INT(183)INT(184)INT(185)INT(186)INT(187)INT(188)INT(189)INT(190)INT(191)INT(192)INT(193)INT(194)INT(195)INT(196)INT(197)INT(198)INT(199)INT(200)INT(201)INT(202)INT(203)INT(204)INT(205)INT(206)INT(207)INT(208)INT(209)INT(210)INT(211)INT(212)INT(213)INT(214)INT(215)INT(216)INT(217)INT(218)INT(219)INT(220)INT(221)INT(222)INT(223)INT(224)INT(225)INT(226)INT(227)INT(228)INT(229)INT(230)INT(231)INT(232)INT(233)INT(234)INT(235)INT(236)INT(237)INT(238)INT(239)INT(240)INT(241)INT(242)INT(243)INT(244)INT(245)INT(246)INT(247)INT(248)INT(249)INT(250)INT(251)INT(252)INT(253)INT(254)INT(255)/* The ll_handler process the request using the kernel function act_int() *//* Then sends EOI & schedules any eventual new task! */ll_handler:/* We do not know what is the DS value *//* Then we save it & set it correctly */pushl %dspushl %sspushl %espushl %fspushl %gs/* But we first transfer to the _act_int *//* the interrupt number which is required *//* as second argument */pushl %eaxmovw $(X_FLATDATA_SEL),%axmovw %ax,%esmov %ax,%dsmovw %ax, %fsmovw %ax, %gs/* Now save the actual context on stack *//* to pass it to _act_int (C caling convention) *//* CLD is necessary when calling a C function */cld/* The following could be optimized a little... */popl %eaxxorl %ebx, %ebxmovw %ss, %bx/* We must switch to a ``safe stack'' *//** OK, this is the idea: in %esp we have the address of the* stack pointer in the APPLICATION address space...* We assume that address spaces are implemented through segments...* What we have to do is to add the segment base to %esp:* - Load the GDT base in a register* - Add DS * 8 to that value* - Read the corresponding GDT entry (the segment descriptor)* - Compute the base...* It is (*p & 0xFC) | (*(p +1) & 0x0F) << 16) | *(p + 2)*/movl SYMBOL_NAME(GDT_base), %ediaddl %ebx, %edixorl %ebx, %ebxmovb 7(%edi), %bhmovb 4(%edi), %blshl $16, %ebxmovw 2(%edi), %bx/* Is it correct? I think so... Test it!!! */addl %ebx, %esp/* Save EBX for returning to our stack... */movw %ss, %dxmovw %ds, %cxmovw %cx, %sspushl %ebxpushl %edxpushl %eaxmovl SYMBOL_NAME(ll_irq_table)(, %eax, 4), %ebxcall *%ebxpopl %ebx /* Store in EBX the Int number */popl %eaxpopl %ecx /* We must subtract it from ESP...*/subl %ecx, %espmovw %ax, %ss/* Resume the return value of _act_int *//* & do the context switch if necessary! */#ifdef __VIRCSW__movw SYMBOL_NAME(currCtx), %axcmpw JmpSel,%axje NoPreempt3movw %ax,JmpSelljmp JmpZone#endifNoPreempt3: popl %gspopl %fspopl %espopl %sspopl %dspopaliretll_handler_master_pic:/* We do not know what is the DS value *//* Then we save it & set it correctly */pushl %dspushl %sspushl %espushl %fspushl %gs/* But we first transfer to the _act_int *//* the interrupt number which is required *//* as second argument */pushl %eaxmovw $(X_FLATDATA_SEL),%axmovw %ax,%esmov %ax,%dsmovw %ax, %fsmovw %ax, %gs/* Now save the actual context on stack *//* to pass it to _act_int (C caling convention) *//* CLD is necessary when calling a C function */cld/* The following could be optimized a little... */popl %eaxxorl %ebx, %ebxmovw %ss, %bx/* We must switch to a ``safe stack'' *//** OK, this is the idea: in %esp we have the address of the* stack pointer in the APPLICATION address space...* We assume that address spaces are implemented through segments...* What we have to do is to add the segment base to %esp:* - Load the GDT base in a register* - Add DS * 8 to that value* - Read the corresponding GDT entry (the segment descriptor)* - Compute the base...* It is (*p & 0xFC) | (*(p +1) & 0x0F) << 16) | *(p + 2)*/movl SYMBOL_NAME(GDT_base), %ediaddl %ebx, %edixorl %ebx, %ebxmovb 7(%edi), %bhmovb 4(%edi), %blshl $16, %ebxmovw 2(%edi), %bx/* Is it correct? I think so... Test it!!! */addl %ebx, %esp/* Save EBX for returning to our stack... */movw %ss, %dxmovw %ds, %cxmovw %cx, %sspushl %ebxpushl %edxpushl %eaxmovl SYMBOL_NAME(ll_irq_table)(, %eax, 4), %ebxcall *%ebxpopl %ebx /* Store in EBX the Int number */popl %eaxpopl %ecx /* We must subtract it from ESP...*/subl %ecx, %espmovw %ax, %ss/* Send EOI to master PIC */movb $0x20,%almovl $0x20,%edxoutb %al,%dx/* Resume the return value of _act_int *//* & do the context switch if necessary! */#ifdef __VIRCSW__movw SYMBOL_NAME(currCtx), %axcmpw JmpSel,%axje NoPreempt4movw %ax,JmpSelljmp JmpZone#endifNoPreempt4: popl %gspopl %fspopl %espopl %sspopl %dspopaliretll_handler_slave_pic:/* We do not know what is the DS value *//* Then we save it & set it correctly */pushl %dspushl %sspushl %espushl %fspushl %gs/* But we first transfer to the _act_int *//* the interrupt number which is required *//* as second argument */pushl %eaxmovw $(X_FLATDATA_SEL),%axmovw %ax,%esmov %ax,%dsmovw %ax, %fsmovw %ax, %gs/* Now save the actual context on stack *//* to pass it to _act_int (C caling convention) *//* CLD is necessary when calling a C function */cld/* The following could be optimized a little... */popl %eaxxorl %ebx, %ebxmovw %ss, %bx/* We must switch to a ``safe stack'' *//** OK, this is the idea: in %esp we have the address of the* stack pointer in the APPLICATION address space...* We assume that address spaces are implemented through segments...* What we have to do is to add the segment base to %esp:* - Load the GDT base in a register* - Add DS * 8 to that value* - Read the corresponding GDT entry (the segment descriptor)* - Compute the base...* It is (*p & 0xFC) | (*(p +1) & 0x0F) << 16) | *(p + 2)*/movl SYMBOL_NAME(GDT_base), %ediaddl %ebx, %edixorl %ebx, %ebxmovb 7(%edi), %bhmovb 4(%edi), %blshl $16, %ebxmovw 2(%edi), %bx/* Is it correct? I think so... Test it!!! */addl %ebx, %esp/* Save EBX for returning to our stack... */movw %ss, %dxmovw %ds, %cxmovw %cx, %sspushl %ebxpushl %edxpushl %eaxmovl SYMBOL_NAME(ll_irq_table)(, %eax, 4), %ebxcall *%ebxpopl %ebx /* Store in EBX the Int number */popl %eaxpopl %ecx /* We must subtract it from ESP...*/subl %ecx, %espmovw %ax, %ss/* Send EOI to master & slave PIC */movb $0x20,%almovl $0xA0,%edxoutb %al,%dxmovl $0x20,%edxoutb %al,%dx/* Resume the return value of _act_int *//* & do the context switch if necessary! */#ifdef __VIRCSW__movw SYMBOL_NAME(currCtx), %axcmpw JmpSel,%axje NoPreempt5movw %ax,JmpSelljmp JmpZone#endifNoPreempt5: popl %gspopl %fspopl %espopl %sspopl %dspopaliret/* OK, this is Exception 7, and it is generated when an ESC or WAIT* intruction is reached, and the MP and TS bits are set... Basically,* it means that the FPU context must be switched*/SYMBOL_NAME_LABEL(exc7) pushalpushl %dspushl %sspushl %espushl %fspushl %gsmovw $(X_FLATDATA_SEL),%axmovw %ax,%esmovw %ax,%dscldcall SYMBOL_NAME(ll_FPU_hook)popl %gspopl %fspopl %espopl %sspopl %dspopaliret