1 files changed, 70 insertions, 4 deletions

diff --git a/arch/blackfin/kernel/early_printk.c b/arch/blackfin/kernel/early_printk.c
index 2ab56811841..931c78b5ea1 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");
 }