Import of Linux/MIPS 2.1.14

1 files changed, 92 insertions, 0 deletions

diff --git a/arch/mips/dec/boot.S b/arch/mips/dec/boot.S
new file mode 100644
index 000000000..587c43623
--- /dev/null
+++ b/arch/mips/dec/boot.S
@@ -0,0 +1,92 @@
+/*
+ * arch/mips/dec/boot.S
+ *
+ * Copyright (C) 1995, 1996 Paul M. Antoine
+ *
+ * Written by Ralf Baechle and Andreas Busse, modified for DECStation
+ * support by Paul Antoine.
+ *
+ * NOTE: There are references to R4X00 code in here, because there is an
+ *	 upgrade module for Personal DECStations with such a CPU!
+ */
+#include <asm/asm.h>
+#include <asm/regdef.h>
+#include <asm/fpregdef.h>
+#include <asm/mipsconfig.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/bootinfo.h>
+
+/*
+ * dec_entry: Called by the boot PROM loader to do DECStation setup, prior
+ *	      to calling dec_setup() to fill in the boot_info structure.
+ *
+ *	      This code should also go in the boot loader for loading off
+ *	      floppy and HD... in addition to the tags code in dec_setup().
+ *
+ *   FIXME:   arrange for this code only to be linked in when building a
+ *	      kernel image to be booted via tftp from the boot prom??
+ */
+		.text
+		.globl	dec_entry
+dec_entry:
+		/* Save the address of the REX call vector for later
+		 * use in printing debug messages.
+		 */
+		sw	a3,pmax_rex_base
+		sw	a2,rex_prom_magic
+		la	a0,dec_signon
+		jal	pmax_printf
+		nop
+
+		/* Now set up the bootinfo with things that
+		 * should be loaded by the boot loader, except that
+		 * for the moment we're booting using tftp.
+		 */
+		jal	dec_setup
+		nop
+/*
+ * Now we need to move exception vector handler routines that appear
+ * in head.S down to the right addresses, 'cos the DECStation loads
+ * kernels at 0x80030000... <sigh>
+ */
+
+/*
+ * First move the TLB refill code down to offset 0x000, at addr 0x80000000
+ */
+		la	t0,except_vec0		# begining of exception code
+		la	t1,except_vec1		# end of exception code
+		la	t2,0x80000000		# where the code should live
+		lw	t3,(t0)			# get first word
+1:		sw	t3,(t2)			# put it where it should go
+		addiu	t0,4			# increment both pointers
+		addiu	t2,4
+		lw	t3,(t0)			# will be in the delay slot
+		bne	t0,t1,1b
+/*
+ * Now move the General Exception code down to offset 0x080 at 0x80000000
+ */
+		la	t0,except_vec3		# begining of general exception code
+		la	t1,end_except		# end of general exception code
+		la	t2,0x80000080		# where the code should live
+		lw	t3,(t0)			# get first word
+1:		sw	t3,(t2)
+		addiu	t0,4
+		addiu	t2,4
+		lw	t3,(t0)
+		bne	t0,t1,1b
+
+		la	a0,dec_launch		# say where we are going
+		jal	pmax_printf
+		nop
+
+		la	t0,mach_mem_upper	# get upper memory bound
+		lw	a0,(t0)
+		j	kernel_entry
+		nop
+
+		.data
+		.align	2
+dec_signon:	.ascii	"\n\nLinux/MIPS DECStation Boot\n";
+		.asciiz "Copyright (C) Paul M. Antoine 1995, 1996 and others, 1994, 1995, 1996\n\n";
+dec_launch:	.asciiz	"Setup complete, launching kernel...\n";