PERFORCE change 134314 for review

[Warner Losh]

http://perforce.freebsd.org/chv.cgi?CH=134314

Change 134314 by imp at imp_lighthouse on 2008/01/28 19:46:51

	When we turn on the COP 1 enable bit, make sure that it turns on
	before accessing the FPU.  In the CPU_NOFPU case, this won't be done,
	but is needed for those platforms that have to support CPUs with and
	without math co-processor support.  Chances are that CPU_NOFPU turns
	off other stuff that will kill us later in the boot process, but for
	now this allows the early startup code to be as agnostic as possible
	at the cost of a few insturctions.

Affected files ...

.. //depot/projects/mips2-jnpr/src/sys/mips/mips/locore.S#12 edit

Differences ...

==== //depot/projects/mips2-jnpr/src/sys/mips/mips/locore.S#12 (text+ko) ====

@@ -126,11 +126,16 @@
 	mtc0	t2, MIPS_COP_0_STATUS
 	COP0_SYNC
 	/* Extra nops for the FPU to spin up. */
+	mfc0	t2, MIPS_COP_0_STATUS
 
 	/* Read and store the PrID FPU ID for CPU identification. */
 	mfc0	t0, MIPS_COP_0_PRID
 #ifndef CPU_NOFPU
+	and	t2, MIPS_SR_COP_1_BIT
+	beqz	t2, 1f
+	li	t1, 0x0
 	cfc1	t1, MIPS_FPU_ID
+1:
 #else
 	/*
 	 * This platform has no FPU, and attempting to detect one
@@ -202,13 +207,6 @@
 	la	sp, _C_LABEL(thread0)
 	lw	a0, TD_PCB(sp)
 	subu	sp, a0, START_FRAME
-	mfc0	t1, COP_0_CONFIG, 1		# Check FPU present or not
-	andi	t1, 0x1
-	beqz	t1, no_fpu
-	nop
-	cfc1	t1, FPC_ID			# read FPU ID register
-	sw	t1, _C_LABEL(fpu_id)		# save FPU ID register
-no_fpu:
 	jal	_C_LABEL(mi_startup)		# mi_startup(frame)
 	nop
 	PANIC("Startup failed!")