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Diffstat (limited to 'arch/blackfin/kernel/early_printk.c')
-rw-r--r--arch/blackfin/kernel/early_printk.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/early_printk.c b/arch/blackfin/kernel/early_printk.c
new file mode 100644
index 00000000000..6ec518a8111
--- /dev/null
+++ b/arch/blackfin/kernel/early_printk.c
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+/*
+ * File: arch/blackfin/kernel/early_printk.c
+ * Based on: arch/x86_64/kernel/early_printk.c
+ * Author: Robin Getz <rgetz@blackfin.uclinux.org
+ *
+ * Created: 14Aug2007
+ * Description: allow a console to be used for early printk
+ *
+ * Modified:
+ * Copyright 2004-2007 Analog Devices Inc.
+ *
+ * Bugs: Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <linux/console.h>
+#include <linux/string.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
+
+static struct console *early_console;
+
+/* 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 |= CS5;
+ break;
+ case 7:
+ cflag |= CS5;
+ 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_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)
+{
+ SSYNC();
+
+ /* cannot program in software:
+ * evt0 - emulation (jtag)
+ * evt1 - reset
+ */
+ bfin_write_EVT2(early_trap);
+ bfin_write_EVT3(early_trap);
+ bfin_write_EVT5(early_trap);
+ bfin_write_EVT6(early_trap);
+ bfin_write_EVT7(early_trap);
+ bfin_write_EVT8(early_trap);
+ bfin_write_EVT9(early_trap);
+ bfin_write_EVT10(early_trap);
+ bfin_write_EVT11(early_trap);
+ bfin_write_EVT12(early_trap);
+ bfin_write_EVT13(early_trap);
+ bfin_write_EVT14(early_trap);
+ bfin_write_EVT15(early_trap);
+ CSYNC();
+
+ /* Set all the return from interupt, 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));
+
+}
+
+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
+ */
+ if (likely(early_console == NULL))
+ setup_early_printk(DEFAULT_EARLY_PORT);
+
+ dump_bfin_regs(fp, retaddr);
+ dump_bfin_trace_buffer();
+
+ panic("Died early");
+}
+
+early_param("earlyprintk", setup_early_printk);