271 lines
6.0 KiB
C
271 lines
6.0 KiB
C
/*
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* allow a console to be used for early printk
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* derived from arch/x86/kernel/early_printk.c
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*
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* Copyright 2007-2009 Analog Devices Inc.
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*
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* Licensed under the GPL-2
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/serial_core.h>
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#include <linux/console.h>
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#include <linux/string.h>
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#include <linux/reboot.h>
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#include <asm/blackfin.h>
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#include <asm/irq_handler.h>
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#include <asm/early_printk.h>
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#ifdef CONFIG_SERIAL_BFIN
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extern struct console *bfin_earlyserial_init(unsigned int port,
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unsigned int cflag);
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#endif
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#ifdef CONFIG_BFIN_JTAG_COMM
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extern struct console *bfin_jc_early_init(void);
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#endif
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/* Default console */
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#define DEFAULT_PORT 0
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#define DEFAULT_CFLAG CS8|B57600
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/* Default console for early crashes */
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#define DEFAULT_EARLY_PORT "serial,uart0,57600"
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#ifdef CONFIG_SERIAL_CORE
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/* What should get here is "0,57600" */
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static struct console * __init earlyserial_init(char *buf)
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{
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int baud, bit;
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char parity;
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unsigned int serial_port = DEFAULT_PORT;
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unsigned int cflag = DEFAULT_CFLAG;
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serial_port = simple_strtoul(buf, &buf, 10);
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buf++;
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cflag = 0;
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baud = simple_strtoul(buf, &buf, 10);
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switch (baud) {
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case 1200:
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cflag |= B1200;
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break;
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case 2400:
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cflag |= B2400;
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break;
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case 4800:
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cflag |= B4800;
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break;
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case 9600:
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cflag |= B9600;
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break;
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case 19200:
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cflag |= B19200;
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break;
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case 38400:
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cflag |= B38400;
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break;
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case 115200:
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cflag |= B115200;
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break;
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default:
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cflag |= B57600;
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}
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parity = buf[0];
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buf++;
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switch (parity) {
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case 'e':
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cflag |= PARENB;
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break;
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case 'o':
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cflag |= PARODD;
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break;
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}
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bit = simple_strtoul(buf, &buf, 10);
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switch (bit) {
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case 5:
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cflag |= CS5;
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break;
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case 6:
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cflag |= CS6;
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break;
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case 7:
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cflag |= CS7;
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break;
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default:
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cflag |= CS8;
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}
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#ifdef CONFIG_SERIAL_BFIN
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return bfin_earlyserial_init(serial_port, cflag);
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#else
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return NULL;
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#endif
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}
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#endif
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int __init setup_early_printk(char *buf)
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{
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/* Crashing in here would be really bad, so check both the var
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and the pointer before we start using it
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*/
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if (!buf)
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return 0;
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if (!*buf)
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return 0;
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if (early_console != NULL)
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return 0;
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#ifdef CONFIG_SERIAL_BFIN
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/* Check for Blackfin Serial */
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if (!strncmp(buf, "serial,uart", 11)) {
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buf += 11;
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early_console = earlyserial_init(buf);
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}
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#endif
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#ifdef CONFIG_BFIN_JTAG_COMM
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/* Check for Blackfin JTAG */
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if (!strncmp(buf, "jtag", 4)) {
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buf += 4;
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early_console = bfin_jc_early_init();
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}
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#endif
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#ifdef CONFIG_FB
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/* TODO: add framebuffer console support */
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#endif
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if (likely(early_console)) {
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early_console->flags |= CON_BOOT;
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register_console(early_console);
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printk(KERN_INFO "early printk enabled on %s%d\n",
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early_console->name,
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early_console->index);
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}
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return 0;
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}
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/*
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* Set up a temporary Event Vector Table, so if something bad happens before
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* the kernel is fully started, it doesn't vector off into somewhere we don't
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* know
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*/
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asmlinkage void __init init_early_exception_vectors(void)
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{
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u32 evt;
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SSYNC();
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/*
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* This starts up the shadow buffer, incase anything crashes before
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* setup arch
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*/
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mark_shadow_error();
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early_shadow_puts(linux_banner);
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early_shadow_stamp();
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if (CPUID != bfin_cpuid()) {
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early_shadow_puts("Running on wrong machine type, expected");
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early_shadow_reg(CPUID, 16);
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early_shadow_puts(", but running on");
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early_shadow_reg(bfin_cpuid(), 16);
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early_shadow_puts("\n");
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}
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/* cannot program in software:
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* evt0 - emulation (jtag)
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* evt1 - reset
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*/
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for (evt = EVT2; evt <= EVT15; evt += 4)
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bfin_write32(evt, early_trap);
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CSYNC();
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/* Set all the return from interrupt, exception, NMI to a known place
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* so if we do a RETI, RETX or RETN by mistake - we go somewhere known
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* Note - don't change RETS - we are in a subroutine, or
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* RETE - since it might screw up if emulator is attached
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*/
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asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
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: : "p"(early_trap));
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}
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__attribute__((__noreturn__))
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asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
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{
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/* This can happen before the uart is initialized, so initialize
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* the UART now (but only if we are running on the processor we think
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* we are compiled for - otherwise we write to MMRs that don't exist,
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* and cause other problems. Nothing comes out the UART, but it does
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* end up in the __buf_log.
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*/
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if (likely(early_console == NULL) && CPUID == bfin_cpuid())
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setup_early_printk(DEFAULT_EARLY_PORT);
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if (!shadow_console_enabled()) {
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/* crap - we crashed before setup_arch() */
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early_shadow_puts("panic before setup_arch\n");
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early_shadow_puts("IPEND:");
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early_shadow_reg(fp->ipend, 16);
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if (fp->seqstat & SEQSTAT_EXCAUSE) {
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early_shadow_puts("\nEXCAUSE:");
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early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8);
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}
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if (fp->seqstat & SEQSTAT_HWERRCAUSE) {
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early_shadow_puts("\nHWERRCAUSE:");
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early_shadow_reg(
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(fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8);
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}
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early_shadow_puts("\nErr @");
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if (fp->ipend & EVT_EVX)
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early_shadow_reg(fp->retx, 32);
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else
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early_shadow_reg(fp->pc, 32);
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#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
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early_shadow_puts("\nTrace:");
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if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
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while (bfin_read_TBUFSTAT() & TBUFCNT) {
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early_shadow_puts("\nT :");
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early_shadow_reg(bfin_read_TBUF(), 32);
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early_shadow_puts("\n S :");
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early_shadow_reg(bfin_read_TBUF(), 32);
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}
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}
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#endif
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early_shadow_puts("\nUse bfin-elf-addr2line to determine "
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"function names\n");
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/*
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* We should panic(), but we can't - since panic calls printk,
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* and printk uses memcpy.
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* we want to reboot, but if the machine type is different,
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* can't due to machine specific reboot sequences
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*/
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if (CPUID == bfin_cpuid()) {
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early_shadow_puts("Trying to restart\n");
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machine_restart("");
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}
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early_shadow_puts("Halting, since it is not safe to restart\n");
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while (1)
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asm volatile ("EMUEXCPT; IDLE;\n");
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} else {
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printk(KERN_EMERG "Early panic\n");
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show_regs(fp);
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dump_bfin_trace_buffer();
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}
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panic("Died early");
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}
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early_param("earlyprintk", setup_early_printk);
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