m68k/fpsp040/skeleton.S

37 |	Modified for Linux-1.3.x by Jes Sorensen (jds@kom.auc.dk)
42 #include <asm/asm-offsets.h>
66 	link		%a6,#-LOCAL_SIZE
67 	fsave		-(%sp)
74 	movel	%sp,%sp@-		| stack frame pointer argument
103 	link		%a6,#-LOCAL_SIZE
104 	fsave		-(%sp)
107 	fmovel		%fpsr,-(%sp)
142 	link		%a6,#-LOCAL_SIZE
143 	fsave		-(%sp)
165 	movel	%sp,%sp@-		| stack frame pointer argument
180 	link		%a6,#-LOCAL_SIZE
181 	fsave		-(%sp)
191 	movel	%sp,%sp@-		| stack frame pointer argument
206 	link		%a6,#-LOCAL_SIZE
207 	fsave		-(%sp)
217 	movel	%sp,%sp@-		| stack frame pointer argument
231 	link		%a6,#-LOCAL_SIZE
232 	fsave		-(%sp)
239 	movel	%sp,%sp@-		| stack frame pointer argument
253 	link		%a6,#-LOCAL_SIZE
254 	fsave		-(%sp)
261 	movel	%sp,%sp@-		| stack frame pointer argument
278 	link		%a6,#-LOCAL_SIZE
279 	fsave		-(%sp)
281 	fmovel		%FPSR,-(%sp)
289 	movel	%sp,%sp@-		| stack frame pointer argument
295 |	F-line exception
297 |	A 'real' F-line exception is one that the FPSP isn't supposed to
298 |	handle. E.g. an instruction with a co-processor ID that is not 1.
310 	movel	%sp,%sp@-		| stack frame pointer argument
324 	link		%a6,#-LOCAL_SIZE
325 	fsave		-(%sp)
332 	movel	%sp,%sp@-		| stack frame pointer argument
346 |	fpsp_fmt_error --- exit point for frame format error
353 |	{4060, 4160} - busy frame
354 |	{4028, 4130} - unimp frame
355 |	{4000, 4100} - idle frame
357 |	This entry point simply holds an f-line illegal value.
364 	.long	0xf27f0000	|f-line illegal
367 |	fpsp_done --- FPSP exit point
370 |	to return to user mode, but there may be OS specific code
377 	btst	#0x5,%sp@		| supervisor bit set in saved SR?
387 |	mem_write --- write to user or supervisor address space
389 | Writes to memory while in supervisor mode.  copyout accomplishes
393 |	a0 - supervisor source address
394 |	a1 - user destination address
395 |	d0 - number of bytes to write (maximum count is 12)
397 | The supervisor source address is guaranteed to point into the supervisor
404 | If the EXC_SR shows that the exception was from supervisor space,
406 | there shouldn't be any supervisor mode floating point exceptions.
410 	btstb	#5,EXC_SR(%a6)	|check for supervisor state
418 	movel	%d1,-(%sp)	|preserve d1 just in case
419 	movel	%d0,-(%sp)
420 	movel	%a1,-(%sp)
421 	movel	%a0,-(%sp)
427 |	mem_read --- read from user or supervisor address space
429 | Reads from memory while in supervisor mode.  copyin accomplishes
433 | The FPSP calls mem_read to read the original F-line instruction in order
434 | to extract the data register number when the 'Dn' addressing mode is
438 |	a0 - user source address
439 |	a1 - supervisor destination address
440 |	d0 - number of bytes to read (maximum count is 12)
442 | Like mem_write, mem_read always reads with a supervisor
443 | destination address on the supervisor stack.  Also like mem_write,
445 | from supervisor space is indicated.
449 	btstb	#5,EXC_SR(%a6)	|check for supervisor state
457 	movel	%d1,-(%sp)	|preserve d1 just in case
458 	movel	%d0,-(%sp)
459 	movel	%a1,-(%sp)
460 	movel	%a0,-(%sp)
481 	moveb	(%a0)+,%d1	| fetch supervisor byte
498 	moveb	%d1,(%a1)+	| write supervisor byte