WebSVN - shark - Blame - Rev 2 - /shark/branches/pj/oslib/xlib/exc.s

Rev	Author	Line No.	Line
2	pj	1	/* Project: OSLib
		2	* Description: The OS Construction Kit
		3	* Date: 1.6.2000
		4	* Idea by: Luca Abeni & Gerardo Lamastra
		5	*
		6	* OSLib is an SO project aimed at developing a common, easy-to-use
		7	* low-level infrastructure for developing OS kernels and Embedded
		8	* Applications; it partially derives from the HARTIK project but it
		9	* currently is independently developed.
		10	*
		11	* OSLib is distributed under GPL License, and some of its code has
		12	* been derived from the Linux kernel source; also some important
		13	* ideas come from studying the DJGPP go32 extender.
		14	*
		15	* We acknowledge the Linux Community, Free Software Foundation,
		16	* D.J. Delorie and all the other developers who believe in the
		17	* freedom of software and ideas.
		18	*
		19	* For legalese, check out the included GPL license.
		20	*/
		21
		22	/* Exc/IRQ handlers (asm part) */
		23	/* TODO: Unify the Exc/Int Mechanism... */
		24
		25	#include <ll/i386/sel.h>
		26	#include <ll/i386/linkage.h>
		27	#include <ll/i386/int.h>
		28	#include <ll/i386/defs.h>
		29
		30	.extern SYMBOL_NAME(GDT_base)
		31	.data
		32
		33	ASMFILE(Exc)
		34
		35	.globl SYMBOL_NAME(ll_irq_table)
		36	.globl SYMBOL_NAME(ll_exc_table)
		37
		38	SYMBOL_NAME_LABEL(ll_irq_table) .space 64, 0
		39	SYMBOL_NAME_LABEL(ll_exc_table) .space 64, 65
		40
		41	.text
		42
		43	.extern SYMBOL_NAME(ll_exc_hook)
		44	.extern SYMBOL_NAME(ll_FPU_hook)
		45
		46	.globl SYMBOL_NAME(h13_bis)
		47	.globl SYMBOL_NAME(exc7)
		48
		49	/* These are the hardware handlers; they all jump to ll_handler setting */
		50	/* the interrupt number into EAX & save the registers on stack */
		51	INT(1)
		52	INT(2)
		53	INT(3)
		54	INT(4)
		55	INT(5)
		56	INT(6)
		57	INT(7)
		58	INT(8)
		59	INT(9)
		60	INT(10)
		61	INT(11)
		62	INT(12)
		63	INT(13)
		64	INT(14)
		65	INT(15)
		66
		67	#if 0
		68	/* MPF... If we have an external FPU, it will generate
		69	* INT 13 instead of EXC 16...
		70	* We must remap it to EXC 16...
		71	*/
		72	#if 1
		73	SYMBOL_NAME_LABEL(h13_bis)
		74	/* Send EOI for 8086 coprocessor trick */
		75	/* Send 0H on Coprocessor port 0F0H */
		76	pushl %eax
		77	xorb %al, %al
		78	outb %al, $0x0F0
		79	movb $0x020, %al
		80	outb %al, $0x0A0
		81	outb %al, $0x020
		82	popl %eax
		83	movl $16, %eax
		84	jmp ll_handler2
		85	#else
		86	SYMBOL_NAME_LABEL(h13_bis) pushal
		87	/* Send EOI for 8086 coprocessor trick */
		88	/* Send 0H on Coprocessor port 0F0H */
		89
		90	xorb %al,%al
		91	outb %al,$0x0F0
		92	movb $0x020,%al
		93	outb %al,$0x0A0
		94	outb %al,$0x020
		95	pushl %ds
		96	pushl %ss
		97	pushl %es
		98	pushl %fs
		99	pushl %gs
		100	movw $(X_FLATDATA_SEL),%ax
		101	movw %ax,%es
		102	movw %ax,%ds
		103	movl $(MATH_EXC),%eax
		104	pushl %eax
		105	/* LL_ABORT OR EXC_HOOK?? */
		106	/THIS SURELY WRONG!!!! FIX IT!!!! Gerardo, help me!!! /
		107	hlt
		108	/* call SYMBOL_NAME(ll_abort) */
		109	addl $4,%esp
		110	popl %gs
		111	popl %fs
		112	popl %es
		113	popl %ss
		114	popl %ds
		115	popal
		116	ret
		117	#endif
		118	#endif
		119
		120	/* The ll_handler process the request using the kernel function act_int() */
		121	/* Then sends EOI & schedules any eventual new task! */
		122
		123	ll_handler:
		124	/* We do not know what is the DS value */
		125	/* Then we save it & set it correctly */
		126
		127	pushl %ds
		128	pushl %ss
		129	pushl %es
		130	pushl %fs
		131	pushl %gs
		132	/* But we first transfer to the _act_int */
		133	/* the interrupt number which is required */
		134	/* as second argument */
		135	pushl %eax
		136	movw $(X_FLATDATA_SEL),%ax
		137	movw %ax,%es
		138	mov %ax,%ds
		139
		140	/* Now save the actual context on stack */
		141	/* to pass it to _act_int (C caling convention) */
		142	/* CLD is necessary when calling a C function */
		143
		144	cld
		145
		146	/* The following could be optimized a little... */
		147	popl %eax
		148	xorl %ebx, %ebx
		149	movw %ss, %bx
		150	/* We must switch to a ``safe stack'' */
		151	#if 0
		152	/*
		153	* OK, this is the idea: in %esp we have the address of the
		154	* stack pointer in the APPLICATION address space...
		155	* We assume that address spaces are implemented through segments...
		156	* What we have to do is to add the segment base to %esp:
		157	* - Load the GDT base in a register
		158	* - Add DS * 8 to that value
		159	* - Read the corresponding GDT entry (the segment descriptor)
		160	* - Compute the base...
		161	* It is (p & 0xFC) \| ((p +1) & 0x0F) << 16) \| *(p + 2)
		162	*/
		163	movl SYMBOL_NAME(GDT_base), %edi
		164	addl %ebx, %edi
		165	xorl %ebx, %ebx
		166	movb 7(%edi), %bh
		167	movb 4(%edi), %bl
		168	shl $16, %ebx
		169	movw 2(%edi), %bx
		170	/* Is it correct? I think so... Test it!!! */
		171	addl %ebx, %esp
		172	/* Save EBX for returning to our stack... */
		173	movw %ss, %dx
		174	movw %ds, %bx
		175	movw %bx, %ss
		176	pushl %ebx
		177	pushl %edx
		178	#endif
		179	pushl %eax
		180
		181	movl SYMBOL_NAME(ll_irq_table)(, %eax, 4), %ebx
		182	call *%ebx
		183
		184	popl %ebx /* Store in EBX the Int number */
		185	#if 0
		186	popl %eax
		187	popl %ecx /* We must subtract it from ESP...*/
		188	subl %ecx, %esp
		189	movw %ax, %ss
		190	#endif
		191	/* Send EOI to master & slave (if necessary) PIC */
		192	movb $0x20,%al
		193	cmpl $0x08,%ebx
		194	jb eoi_master
		195	eoi_slave: movl $0xA0,%edx
		196	outb %al,%dx
		197	eoi_master: movl $0x20,%edx
		198	outb %al,%dx
		199
		200	/* Resume the return value of _act_int */
		201	/* & do the context switch if necessary! */
		202	#ifdef __VIRCSW__
		203	movw SYMBOL_NAME(currCtx), %ax
		204	cmpw JmpSel,%ax
		205	je NoPreempt3
		206	movw %ax,JmpSel
		207	ljmp JmpZone
		208	#endif
		209	NoPreempt3: popl %gs
		210	popl %fs
		211	popl %es
		212	popl %ss
		213	popl %ds
		214	popal
		215	iret
		216
		217
		218	EXC(0)
		219	EXC(1)
		220	EXC(2)
		221	EXC(3)
		222	EXC(4)
		223	EXC(5)
		224	EXC(6)
		225	EXC(8)
		226	EXC(9)
		227	EXC(10)
		228	EXC(11)
		229	EXC(12)
		230	EXC(13)
		231	EXC(14)
		232	EXC(15)
		233	EXC(16)
		234
		235	/* OK, this is Exception 7, and it is generated when an ESC or WAIT
		236	* intruction is reached, and the MP and TS bits are set... Basically,
		237	* it means that the FPU context must be switched
		238	*/
		239	SYMBOL_NAME_LABEL(exc7) pushal
		240	pushl %ds
		241	pushl %ss
		242	pushl %es
		243	pushl %fs
		244	pushl %gs
		245	movw $(X_FLATDATA_SEL),%ax
		246	movw %ax,%es
		247	movw %ax,%ds
		248	cld
		249	call SYMBOL_NAME(ll_FPU_hook)
		250	popl %gs
		251	popl %fs
		252	popl %es
		253	popl %ss
		254	popl %ds
		255	popal
		256	iret
		257
		258	ll_handler2:
		259	pushl %eax
		260	movw $(X_FLATDATA_SEL),%ax
		261	movw %ax,%ds
		262	movw %ax,%es
		263
		264
		265	/* Again, the following could be optimized... */
		266	/*
		267	If the Exception raised in a different address space, we have to
		268	access the task stack from the kernel address space (the linear one...)
		269	*/
		270	popl %eax
		271	movw %ss, %bx
		272	/* We must switch to a ``safe stack'' */
		273	movl SYMBOL_NAME(GDT_base), %edi
		274	addl %ebx, %edi
		275	xorl %ebx, %ebx
		276	movb 7(%edi), %bh
		277	movb 4(%edi), %bl
		278	shl $16, %ebx
		279	movw 2(%edi), %bx
		280	/* Is it correct? I think so... Test it!!! */
		281	addl %ebx, %esp
		282	/* Save EBX for returning to our stack... */
		283	movw %ss, %dx
		284	movw %ds, %bx
		285	movw %bx, %ss
		286	pushl %ebx
		287	pushl %edx
		288	pushl %eax
		289	call *SYMBOL_NAME(ll_exc_table)(, %eax, 4)
		290	addl $4,%esp
		291
		292	/* Restore the stack pointer!!! */
		293	popl %eax
		294	popl %ebx
		295	movw %ax, %ss
		296	subl %ebx, %esp
		297	iret

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