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Diffstat (limited to 'arch/blackfin/kernel/early_printk.c')
-rw-r--r--arch/blackfin/kernel/early_printk.c270
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);