From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/blackfin/kernel/early_printk.c | 270 ++++++++++++++++++++++++++++++++++++ 1 file changed, 270 insertions(+) create mode 100644 arch/blackfin/kernel/early_printk.c (limited to 'arch/blackfin/kernel/early_printk.c') 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#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); -- cgit v1.2.3-54-g00ecf