1 files changed, 270 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/early_printk.c b/arch/blackfin/kernel/early_printk.c
new file mode 100644
index 000000000..61fbd2de9
--- /dev/null
+++ b/arch/blackfin/kernel/early_printk.c
@@ -0,0 +1,270 @@
+/*
+ * allow a console to be used for early printk
+ * derived from arch/x86/kernel/early_printk.c
+ *
+ * Copyright 2007-2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#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>
+
+#ifdef CONFIG_SERIAL_BFIN
+extern struct console *bfin_earlyserial_init(unsigned int port,
+						unsigned int cflag);
+#endif
+#ifdef CONFIG_BFIN_JTAG_COMM
+extern struct console *bfin_jc_early_init(void);
+#endif
+
+/* Default console */
+#define DEFAULT_PORT 0
+#define DEFAULT_CFLAG CS8|B57600
+
+/* Default console for early crashes */
+#define DEFAULT_EARLY_PORT "serial,uart0,57600"
+
+#ifdef CONFIG_SERIAL_CORE
+/* What should get here is "0,57600" */
+static struct console * __init earlyserial_init(char *buf)
+{
+	int baud, bit;
+	char parity;
+	unsigned int serial_port = DEFAULT_PORT;
+	unsigned int cflag = DEFAULT_CFLAG;
+
+	serial_port = simple_strtoul(buf, &buf, 10);
+	buf++;
+
+	cflag = 0;
+	baud = simple_strtoul(buf, &buf, 10);
+	switch (baud) {
+	case 1200:
+		cflag |= B1200;
+		break;
+	case 2400:
+		cflag |= B2400;
+		break;
+	case 4800:
+		cflag |= B4800;
+		break;
+	case 9600:
+		cflag |= B9600;
+		break;
+	case 19200:
+		cflag |= B19200;
+		break;
+	case 38400:
+		cflag |= B38400;
+		break;
+	case 115200:
+		cflag |= B115200;
+		break;
+	default:
+		cflag |= B57600;
+	}
+
+	parity = buf[0];
+	buf++;
+	switch (parity) {
+	case 'e':
+		cflag |= PARENB;
+		break;
+	case 'o':
+		cflag |= PARODD;
+		break;
+	}
+
+	bit = simple_strtoul(buf, &buf, 10);
+	switch (bit) {
+	case 5:
+		cflag |= CS5;
+		break;
+	case 6:
+		cflag |= CS6;
+		break;
+	case 7:
+		cflag |= CS7;
+		break;
+	default:
+		cflag |= CS8;
+	}
+
+#ifdef CONFIG_SERIAL_BFIN
+	return bfin_earlyserial_init(serial_port, cflag);
+#else
+	return NULL;
+#endif
+
+}
+#endif
+
+int __init setup_early_printk(char *buf)
+{
+
+	/* Crashing in here would be really bad, so check both the var
+	   and the pointer before we start using it
+	 */
+	if (!buf)
+		return 0;
+
+	if (!*buf)
+		return 0;
+
+	if (early_console != NULL)
+		return 0;
+
+#ifdef CONFIG_SERIAL_BFIN
+	/* Check for Blackfin Serial */
+	if (!strncmp(buf, "serial,uart", 11)) {
+		buf += 11;
+		early_console = earlyserial_init(buf);
+	}
+#endif
+
+#ifdef CONFIG_BFIN_JTAG_COMM
+	/* Check for Blackfin JTAG */
+	if (!strncmp(buf, "jtag", 4)) {
+		buf += 4;
+		early_console = bfin_jc_early_init();
+	}
+#endif
+
+#ifdef CONFIG_FB
+		/* TODO: add framebuffer console support */
+#endif
+
+	if (likely(early_console)) {
+		early_console->flags |= CON_BOOT;
+
+		register_console(early_console);
+		printk(KERN_INFO "early printk enabled on %s%d\n",
+			early_console->name,
+			early_console->index);
+	}
+
+	return 0;
+}
+
+/*
+ * Set up a temporary Event Vector Table, so if something bad happens before
+ * the kernel is fully started, it doesn't vector off into somewhere we don't
+ * know
+ */
+
+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
+	 */
+	for (evt = EVT2; evt <= EVT15; evt += 4)
+		bfin_write32(evt, early_trap);
+	CSYNC();
+
+	/* Set all the return from interrupt, exception, NMI to a known place
+	 * so if we do a RETI, RETX or RETN by mistake - we go somewhere known
+	 * Note - don't change RETS - we are in a subroutine, or
+	 * RETE - since it might screw up if emulator is attached
+	 */
+	asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
+		: : "p"(early_trap));
+
+}
+
+__attribute__((__noreturn__))
+asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
+{
+	/* This can happen before the uart is initialized, so initialize
+	 * the UART now (but only if we are running on the processor we think
+	 * we are compiled for - otherwise we write to MMRs that don't exist,
+	 * and cause other problems. Nothing comes out the UART, but it does
+	 * end up in the __buf_log.
+	 */
+	if (likely(early_console == NULL) && CPUID == bfin_cpuid())
+		setup_early_printk(DEFAULT_EARLY_PORT);
+
+	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");
+}
+
+early_param("earlyprintk", setup_early_printk);