patch-2.3.9 linux/arch/mips/baget/balo.c

• Lines: 191
• Date: Fri Jun 25 17:40:12 1999
• Orig file: v2.3.8/linux/arch/mips/baget/balo.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.8/linux/arch/mips/baget/balo.c linux/arch/mips/baget/balo.c
@@ -0,0 +1,190 @@
+/* $Id$
+ *
+ * balo.c: BAget LOader
+ *
+ * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
+ *
+ */
+#include <linux/kernel.h>
+#include <asm/system.h>
+#include <asm/ptrace.h>
+#include <asm/addrspace.h>
+
+#include <asm/baget/baget.h>
+
+#include "balo.h"  /* Includes some kernel symbol values */
+
+static char *banner = "\nBaget Linux Loader v0.2\n";
+
+static void mem_move (long *to, long *from, long size)
+{
+	while (size > 0) { 
+		*to++ = *from++;
+		size -= sizeof(long);
+	}
+}
+
+static volatile int *mem_limit     = (volatile int*)KSEG1;
+static volatile int *mem_limit_dbe = (volatile int*)KSEG1;
+
+static int can_write (volatile int* p) {
+        return p <  (int*)(KSEG1+BALO_OFFSET) ||
+               p >= (int*)(KSEG1+BALO_OFFSET+BALO_SIZE);
+}
+
+static volatile enum balo_state_enum {
+	BALO_INIT,
+	MEM_INIT,
+	MEM_PROBE,
+	START_KERNEL
+} balo_state = BALO_INIT;
+
+
+static __inline__ void reset_and_jump(int start, int mem_upper)
+{
+	__asm__ __volatile__(
+                ".set\tnoreorder\n\t"
+                ".set\tnoat\n\t"
+                "mfc0\t$1,$12\n\t"
+                "nop\n\t"
+                "nop\n\t"
+                "nop\n\t"
+                "ori\t$1,$1,0xff00\n\t"
+                "xori\t$1,$1,0xff00\n\t"
+                "mtc0\t$1,$12\n\t"
+                "nop\n\t"
+                "nop\n\t"
+                "nop\n\t"
+		"move\t$4,%1\n\t"
+		"jr\t%0\n\t"
+		"nop\n\t"
+                ".set\tat\n\t"
+                ".set\treorder"           
+                : /* no outputs */
+                :"Ir" (start), "Ir" (mem_upper)
+                :"$1", "$4", "memory");
+}
+
+static void start_kernel(void)
+{
+	extern char _vmlinux_start, _vmlinux_end;
+	extern char _ramdisk_start, _ramdisk_end;
+
+        outs( "Relocating Linux... " );
+	mem_move((long*)KSEG0, (long*)&_vmlinux_start, 
+                 &_vmlinux_end-&_vmlinux_start);
+	outs("done.\n");
+
+	if (&_ramdisk_start != &_ramdisk_end) {
+		outs("Setting up RAMDISK... ");
+		if (*(unsigned long*)RAMDISK_BASE != 0xBA) {
+			outs("Bad RAMDISK_BASE signature in system image.\n");
+                        balo_hungup();
+		}
+		*(unsigned long*)RAMDISK_BASE = (unsigned long)&_ramdisk_start;
+		*(unsigned long*)RAMDISK_SIZE = &_ramdisk_end -&_ramdisk_start;
+		outs("done.\n");
+	}
+
+	{ 
+		extern void flush_cache_low(int isize, int dsize);
+		flush_cache_low(256*1024,256*1024);
+	}
+
+        balo_printf( "Kernel entry: %x\n\n", START);
+	balo_state = START_KERNEL;
+	reset_and_jump(START, (int)mem_limit-KSEG1+KSEG0);
+}
+
+
+static void mem_probe(void)
+{
+	balo_state = MEM_PROBE;
+	outs("RAM: <");
+	while(mem_limit < mem_limit_dbe) {
+                if (can_write(mem_limit) && *mem_limit != 0) 
+                        break; /* cycle found */
+		outc('.');
+		if (can_write(mem_limit)) 
+                        *mem_limit = -1; /* mark */
+                mem_limit += 0x40000;
+	}
+	outs(">\n");
+	start_kernel();
+}
+
+volatile unsigned int int_cause;
+volatile unsigned int epc;
+volatile unsigned int badvaddr;
+
+static void print_regs(void)
+{
+        balo_printf("CAUSE=%x EPC=%x BADVADDR=%x\n",
+                    int_cause, epc, badvaddr);
+}
+
+void int_handler(struct pt_regs *regs)
+{ 
+        switch (balo_state) {
+	case BALO_INIT:
+                balo_printf("\nBALO: trap in balo itself.\n");
+		print_regs();
+                balo_hungup();
+		break;
+	case MEM_INIT:
+                if ((int_cause & CAUSE_MASK) != CAUSE_DBE) {
+                        balo_printf("\nBALO: unexpected trap during memory init.\n");
+			print_regs();
+                        balo_hungup();
+		} else {
+			mem_probe();
+		}
+		break;
+	case MEM_PROBE:
+                balo_printf("\nBALO: unexpected trap during memory probe.\n");
+		print_regs();
+                balo_hungup();
+		break;
+	case START_KERNEL:
+                balo_printf("\nBALO: unexpected kernel trap.\n");
+		print_regs();
+                balo_hungup();
+		break;
+	}
+        balo_printf("\nBALO: unexpected return from handler.\n");
+	print_regs();
+        balo_hungup();
+}
+
+static void mem_init(void)
+{
+	balo_state = MEM_INIT;
+
+	while(1) {
+		*mem_limit_dbe;
+		if (can_write(mem_limit_dbe)) 
+			*mem_limit_dbe = 0;
+
+		mem_limit_dbe += 0x40000; /* +1M */
+	}
+        /*  no return: must go to int_handler */
+}
+
+void balo_entry(void)
+{
+        extern void except_vec3_generic(void);
+
+	cli(); 
+	outs(banner);
+        memcpy((void *)(KSEG0 + 0x80), &except_vec3_generic, 0x80);
+	mem_init();
+}
+
+/* Needed for linking */
+
+int vsprintf(char *buf, const char *fmt, va_list arg)
+{
+	outs("BALO: vsprintf called.\n");
+	balo_hungup();
+	return 0;
+}