173 lines
3.9 KiB
C
173 lines
3.9 KiB
C
/*
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* C interface for trapping into the standard LinuxSH BIOS.
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*
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* Copyright (C) 2000 Greg Banks, Mitch Davis
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* Copyright (C) 1999, 2000 Niibe Yutaka
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* Copyright (C) 2002 M. R. Brown
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* Copyright (C) 2004 - 2010 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/module.h>
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#include <linux/console.h>
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#include <linux/tty.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/delay.h>
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#include <asm/sh_bios.h>
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#define BIOS_CALL_CONSOLE_WRITE 0
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#define BIOS_CALL_ETH_NODE_ADDR 10
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#define BIOS_CALL_SHUTDOWN 11
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#define BIOS_CALL_GDB_DETACH 0xff
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void *gdb_vbr_vector = NULL;
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static inline long sh_bios_call(long func, long arg0, long arg1, long arg2,
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long arg3)
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{
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register long r0 __asm__("r0") = func;
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register long r4 __asm__("r4") = arg0;
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register long r5 __asm__("r5") = arg1;
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register long r6 __asm__("r6") = arg2;
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register long r7 __asm__("r7") = arg3;
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if (!gdb_vbr_vector)
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return -ENOSYS;
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__asm__ __volatile__("trapa #0x3f":"=z"(r0)
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:"0"(r0), "r"(r4), "r"(r5), "r"(r6), "r"(r7)
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:"memory");
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return r0;
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}
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void sh_bios_console_write(const char *buf, unsigned int len)
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{
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sh_bios_call(BIOS_CALL_CONSOLE_WRITE, (long)buf, (long)len, 0, 0);
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}
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void sh_bios_gdb_detach(void)
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{
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sh_bios_call(BIOS_CALL_GDB_DETACH, 0, 0, 0, 0);
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}
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EXPORT_SYMBOL_GPL(sh_bios_gdb_detach);
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void sh_bios_get_node_addr(unsigned char *node_addr)
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{
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sh_bios_call(BIOS_CALL_ETH_NODE_ADDR, 0, (long)node_addr, 0, 0);
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}
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EXPORT_SYMBOL_GPL(sh_bios_get_node_addr);
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void sh_bios_shutdown(unsigned int how)
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{
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sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0);
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}
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/*
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* Read the old value of the VBR register to initialise the vector
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* through which debug and BIOS traps are delegated by the Linux trap
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* handler.
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*/
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void sh_bios_vbr_init(void)
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{
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unsigned long vbr;
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if (unlikely(gdb_vbr_vector))
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return;
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__asm__ __volatile__ ("stc vbr, %0" : "=r" (vbr));
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if (vbr) {
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gdb_vbr_vector = (void *)(vbr + 0x100);
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printk(KERN_NOTICE "Setting GDB trap vector to %p\n",
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gdb_vbr_vector);
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} else
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printk(KERN_NOTICE "SH-BIOS not detected\n");
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}
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/**
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* sh_bios_vbr_reload - Re-load the system VBR from the BIOS vector.
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*
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* This can be used by save/restore code to reinitialize the system VBR
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* from the fixed BIOS VBR. A no-op if no BIOS VBR is known.
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*/
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void sh_bios_vbr_reload(void)
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{
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if (gdb_vbr_vector)
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__asm__ __volatile__ (
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"ldc %0, vbr"
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:
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: "r" (((unsigned long) gdb_vbr_vector) - 0x100)
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: "memory"
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);
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}
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#ifdef CONFIG_EARLY_PRINTK
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/*
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* Print a string through the BIOS
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*/
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static void sh_console_write(struct console *co, const char *s,
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unsigned count)
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{
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sh_bios_console_write(s, count);
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}
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/*
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* Setup initial baud/bits/parity. We do two things here:
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* - construct a cflag setting for the first rs_open()
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* - initialize the serial port
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* Return non-zero if we didn't find a serial port.
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*/
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static int __init sh_console_setup(struct console *co, char *options)
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{
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int cflag = CREAD | HUPCL | CLOCAL;
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/*
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* Now construct a cflag setting.
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* TODO: this is a totally bogus cflag, as we have
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* no idea what serial settings the BIOS is using, or
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* even if its using the serial port at all.
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*/
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cflag |= B115200 | CS8 | /*no parity*/0;
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co->cflag = cflag;
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return 0;
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}
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static struct console bios_console = {
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.name = "bios",
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.write = sh_console_write,
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.setup = sh_console_setup,
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.flags = CON_PRINTBUFFER,
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.index = -1,
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};
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static int __init setup_early_printk(char *buf)
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{
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int keep_early = 0;
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if (!buf)
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return 0;
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if (strstr(buf, "keep"))
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keep_early = 1;
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if (!strncmp(buf, "bios", 4))
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early_console = &bios_console;
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if (likely(early_console)) {
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if (keep_early)
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early_console->flags &= ~CON_BOOT;
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else
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early_console->flags |= CON_BOOT;
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register_console(early_console);
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}
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return 0;
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}
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early_param("earlyprintk", setup_early_printk);
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#endif
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