4 files changed, 122 insertions, 12 deletions

diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index 9f9b82816652..14dea1a87b7c 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/arch/blackfin/kernel/bfin_dma_5xx.c
@@ -19,6 +19,7 @@
 #include <asm/cacheflush.h>
 #include <asm/dma.h>
 #include <asm/uaccess.h>
+#include <asm/early_printk.h>
 
 /*
  * To make sure we work around 05000119 - we always check DMA_DONE bit,
@@ -236,6 +237,7 @@ void blackfin_dma_resume(void)
  */
 void __init blackfin_dma_early_init(void)
 {
+	early_shadow_stamp();
 	bfin_write_MDMA_S0_CONFIG(0);
 	bfin_write_MDMA_S1_CONFIG(0);
 }
@@ -246,6 +248,8 @@ void __init early_dma_memcpy(void *pdst, const void *psrc, size_t size)
 	unsigned long src = (unsigned long)psrc;
 	struct dma_register *dst_ch, *src_ch;
 
+	early_shadow_stamp();
+
 	/* We assume that everything is 4 byte aligned, so include
 	 * a basic sanity check
 	 */
@@ -300,6 +304,8 @@ void __init early_dma_memcpy(void *pdst, const void *psrc, size_t size)
 
 void __init early_dma_memcpy_done(void)
 {
+	early_shadow_stamp();
+
 	while ((bfin_read_MDMA_S0_CONFIG() && !(bfin_read_MDMA_D0_IRQ_STATUS() & DMA_DONE)) ||
 	       (bfin_read_MDMA_S1_CONFIG() && !(bfin_read_MDMA_D1_IRQ_STATUS() & DMA_DONE)))
 		continue;
diff --git a/arch/blackfin/kernel/early_printk.c b/arch/blackfin/kernel/early_printk.c
index 2ab56811841c..931c78b5ea1f 100644
--- a/arch/blackfin/kernel/early_printk.c
+++ b/arch/blackfin/kernel/early_printk.c
@@ -27,6 +27,7 @@
 #include <linux/serial_core.h>
 #include <linux/console.h>
 #include <linux/string.h>
+#include <linux/reboot.h>
 #include <asm/blackfin.h>
 #include <asm/irq_handler.h>
 #include <asm/early_printk.h>
@@ -181,6 +182,22 @@ asmlinkage void __init init_early_exception_vectors(void)
 	u32 evt;
 	SSYNC();
 
+	/*
+	 * This starts up the shadow buffer, incase anything crashes before
+	 * setup arch
+	 */
+	mark_shadow_error();
+	early_shadow_puts(linux_banner);
+	early_shadow_stamp();
+
+	if (CPUID != bfin_cpuid()) {
+		early_shadow_puts("Running on wrong machine type, expected");
+		early_shadow_reg(CPUID, 16);
+		early_shadow_puts(", but running on");
+		early_shadow_reg(bfin_cpuid(), 16);
+		early_shadow_puts("\n");
+	}
+
 	/* cannot program in software:
 	 * evt0 - emulation (jtag)
 	 * evt1 - reset
@@ -199,6 +216,7 @@ asmlinkage void __init init_early_exception_vectors(void)
 
 }
 
+__attribute__((__noreturn__))
 asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
 {
 	/* This can happen before the uart is initialized, so initialize
@@ -210,10 +228,58 @@ asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
 	if (likely(early_console == NULL) && CPUID == bfin_cpuid())
 		setup_early_printk(DEFAULT_EARLY_PORT);
 
-	printk(KERN_EMERG "Early panic\n");
-	dump_bfin_mem(fp);
-	show_regs(fp);
-	dump_bfin_trace_buffer();
+	if (!shadow_console_enabled()) {
+		/* crap - we crashed before setup_arch() */
+		early_shadow_puts("panic before setup_arch\n");
+		early_shadow_puts("IPEND:");
+		early_shadow_reg(fp->ipend, 16);
+		if (fp->seqstat & SEQSTAT_EXCAUSE) {
+			early_shadow_puts("\nEXCAUSE:");
+			early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8);
+		}
+		if (fp->seqstat & SEQSTAT_HWERRCAUSE) {
+			early_shadow_puts("\nHWERRCAUSE:");
+			early_shadow_reg(
+				(fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8);
+		}
+		early_shadow_puts("\nErr @");
+		if (fp->ipend & EVT_EVX)
+			early_shadow_reg(fp->retx, 32);
+		else
+			early_shadow_reg(fp->pc, 32);
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
+		early_shadow_puts("\nTrace:");
+		if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
+			while (bfin_read_TBUFSTAT() & TBUFCNT) {
+				early_shadow_puts("\nT  :");
+				early_shadow_reg(bfin_read_TBUF(), 32);
+				early_shadow_puts("\n S :");
+				early_shadow_reg(bfin_read_TBUF(), 32);
+			}
+		}
+#endif
+		early_shadow_puts("\nUse bfin-elf-addr2line to determine "
+			"function names\n");
+		/*
+		 * We should panic(), but we can't - since panic calls printk,
+		 * and printk uses memcpy.
+		 * we want to reboot, but if the machine type is different,
+		 * can't due to machine specific reboot sequences
+		 */
+		if (CPUID == bfin_cpuid()) {
+			early_shadow_puts("Trying to restart\n");
+			machine_restart("");
+		}
+
+		early_shadow_puts("Halting, since it is not safe to restart\n");
+		while (1)
+			asm volatile ("EMUEXCPT; IDLE;\n");
+
+	} else {
+		printk(KERN_EMERG "Early panic\n");
+		show_regs(fp);
+		dump_bfin_trace_buffer();
+	}
 
 	panic("Died early");
 }
diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c
index 3974764acd2c..f92fffc31689 100644
--- a/arch/blackfin/kernel/setup.c
+++ b/arch/blackfin/kernel/setup.c
@@ -187,6 +187,8 @@ void __init bfin_relocate_l1_mem(void)
 	unsigned long l1_data_b_length;
 	unsigned long l2_length;
 
+	early_shadow_stamp();
+
 	/*
 	 * due to the ALIGN(4) in the arch/blackfin/kernel/vmlinux.lds.S
 	 * we know that everything about l1 text/data is nice and aligned,
@@ -1352,6 +1354,7 @@ const struct seq_operations cpuinfo_op = {
 
 void __init cmdline_init(const char *r0)
 {
+	early_shadow_stamp();
 	if (r0)
 		strncpy(command_line, r0, COMMAND_LINE_SIZE);
 }
diff --git a/arch/blackfin/kernel/shadow_console.c b/arch/blackfin/kernel/shadow_console.c
index 15819ff10573..8b8c7107a162 100644
--- a/arch/blackfin/kernel/shadow_console.c
+++ b/arch/blackfin/kernel/shadow_console.c
@@ -24,15 +24,18 @@
 
 static __initdata char *shadow_console_buffer = (char *)SHADOW_CONSOLE_START;
 
-static __init void early_shadow_write(struct console *con, const char *s,
+__init void early_shadow_write(struct console *con, const char *s,
 				unsigned int n)
 {
+	unsigned int i;
 	/*
 	 * save 2 bytes for the double null at the end
 	 * once we fail on a long line, make sure we don't write a short line afterwards
 	 */
 	if ((shadow_console_buffer + n) <= (char *)(SHADOW_CONSOLE_END - 2)) {
-		memcpy(shadow_console_buffer, s, n);
+		/* can't use memcpy - it may not be relocated yet */
+		for (i = 0; i <= n; i++)
+			shadow_console_buffer[i] = s[i];
 		shadow_console_buffer += n;
 		shadow_console_buffer[0] = 0;
 		shadow_console_buffer[1] = 0;
@@ -48,16 +51,24 @@ static __initdata struct console early_shadow_console = {
 	.device = 0,
 };
 
-__init void enable_shadow_console(void)
+__init int shadow_console_enabled(void)
+{
+	return early_shadow_console.flags & CON_ENABLED;
+}
+
+__init void mark_shadow_error(void)
 {
 	int *loc = (int *)SHADOW_CONSOLE_MAGIC_LOC;
+	loc[0] = SHADOW_CONSOLE_MAGIC;
+	loc[1] = SHADOW_CONSOLE_START;
+}
 
-	if (!(early_shadow_console.flags & CON_ENABLED)) {
+__init void enable_shadow_console(void)
+{
+	if (!shadow_console_enabled()) {
 		register_console(&early_shadow_console);
 		/* for now, assume things are going to fail */
-		*loc = SHADOW_CONSOLE_MAGIC;
-		loc++;
-		*loc = SHADOW_CONSOLE_START;
+		mark_shadow_error();
 	}
 }
 
@@ -71,8 +82,32 @@ static __init int disable_shadow_console(void)
 	 */
 	int *loc = (int *)SHADOW_CONSOLE_MAGIC_LOC;
 
-	*loc = 0;
+	loc[0] = 0;
 
 	return 0;
 }
 pure_initcall(disable_shadow_console);
+
+/*
+ * since we can't use printk, dump numbers (as hex), n = # bits
+ */
+__init void early_shadow_reg(unsigned long reg, unsigned int n)
+{
+	/*
+	 * can't use any "normal" kernel features, since thay
+	 * may not be relocated to their execute address yet
+	 */
+	int i;
+	char ascii[11] = " 0x";
+
+	n = n / 4;
+	reg = reg << ((8 - n) * 4);
+	n += 3;
+
+	for (i = 3; i <= n ; i++) {
+		ascii[i] = hex_asc_lo(reg >> 28);
+		reg <<= 4;
+	}
+	early_shadow_write(NULL, ascii, n);
+
+}