misc.c

linux内核源码

/*
 * misc.c
 *
 * $Id: misc.c,v 1.8 2005/04/24 18:34:29 starvik Exp $
 *
 * This is a collection of several routines from gzip-1.0.3
 * adapted for Linux.
 *
 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
 * puts by Nick Holloway 1993, better puts by Martin Mares 1995
 * adaptation for Linux/CRIS Axis Communications AB, 1999
 *
 */

/* where the piggybacked kernel image expects itself to live.
 * it is the same address we use when we network load an uncompressed
 * image into DRAM, and it is the address the kernel is linked to live
 * at by vmlinux.lds.S
 */

#define KERNEL_LOAD_ADR 0x40004000


#include <linux/types.h>
#include <asm/arch/hwregs/reg_rdwr.h>
#include <asm/arch/hwregs/reg_map.h>
#include <asm/arch/hwregs/ser_defs.h>

/*
 * gzip declarations
 */

#define OF(args)  args
#define STATIC static

void* memset(void* s, int c, size_t n);
void* memcpy(void* __dest, __const void* __src,
	     size_t __n);

#define memzero(s, n)     memset ((s), 0, (n))


typedef unsigned char  uch;
typedef unsigned short ush;
typedef unsigned long  ulg;

#define WSIZE 0x8000		/* Window size must be at least 32k, */
				/* and a power of two */

static uch *inbuf;	     /* input buffer */
static uch window[WSIZE];    /* Sliding window buffer */

unsigned inptr = 0;	/* index of next byte to be processed in inbuf
			 * After decompression it will contain the
			 * compressed size, and head.S will read it.
			 */

static unsigned outcnt = 0;  /* bytes in output buffer */

/* gzip flag byte */
#define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
#define COMMENT      0x10 /* bit 4 set: file comment present */
#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
#define RESERVED     0xC0 /* bit 6,7:   reserved */

#define get_byte() inbuf[inptr++]

/* Diagnostic functions */
#ifdef DEBUG
#  define Assert(cond,msg) {if(!(cond)) error(msg);}
#  define Trace(x) fprintf x
#  define Tracev(x) {if (verbose) fprintf x ;}
#  define Tracevv(x) {if (verbose>1) fprintf x ;}
#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
#else
#  define Assert(cond,msg)
#  define Trace(x)
#  define Tracev(x)
#  define Tracevv(x)
#  define Tracec(c,x)
#  define Tracecv(c,x)
#endif

static int  fill_inbuf(void);
static void flush_window(void);
static void error(char *m);
static void gzip_mark(void **);
static void gzip_release(void **);

extern char *input_data;  /* lives in head.S */

static long bytes_out = 0;
static uch *output_data;
static unsigned long output_ptr = 0;

static void *malloc(int size);
static void free(void *where);
static void error(char *m);
static void gzip_mark(void **);
static void gzip_release(void **);

static void puts(const char *);

/* the "heap" is put directly after the BSS ends, at end */

extern int _end;
static long free_mem_ptr = (long)&_end;

#include "../../../../../lib/inflate.c"

static void *malloc(int size)
{
	void *p;

	if (size <0) error("Malloc error");

	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */

	p = (void *)free_mem_ptr;
	free_mem_ptr += size;

	return p;
}

static void free(void *where)
{	/* Don't care */
}

static void gzip_mark(void **ptr)
{
	*ptr = (void *) free_mem_ptr;
}

static void gzip_release(void **ptr)
{
	free_mem_ptr = (long) *ptr;
}

/* decompressor info and error messages to serial console */

static inline void
serout(const char *s, reg_scope_instances regi_ser)
{
	reg_ser_rs_stat_din rs;
	reg_ser_rw_dout dout = {.data = *s};

	do {
		rs = REG_RD(ser, regi_ser, rs_stat_din);
	}
	while (!rs.tr_rdy);/* Wait for transceiver. */

	REG_WR(ser, regi_ser, rw_dout, dout);
}

static void
puts(const char *s)
{
#ifndef CONFIG_ETRAX_DEBUG_PORT_NULL
	while (*s) {
#ifdef CONFIG_ETRAX_DEBUG_PORT0
		serout(s, regi_ser0);
#endif
#ifdef CONFIG_ETRAX_DEBUG_PORT1
		serout(s, regi_ser1);
#endif
#ifdef CONFIG_ETRAX_DEBUG_PORT2
		serout(s, regi_ser2);
#endif
#ifdef CONFIG_ETRAX_DEBUG_PORT3
		serout(s, regi_ser3);
#endif
		*s++;
	}
/* CONFIG_ETRAX_DEBUG_PORT_NULL */
#endif
}

void*
memset(void* s, int c, size_t n)
{
	int i;
	char *ss = (char*)s;

	for (i=0;i<n;i++) ss[i] = c;
}

void*
memcpy(void* __dest, __const void* __src,
			    size_t __n)
{
	int i;
	char *d = (char *)__dest, *s = (char *)__src;

	for (i=0;i<__n;i++) d[i] = s[i];
}

/* ===========================================================================
 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 * (Used for the decompressed data only.)
 */

static void
flush_window()
{
    ulg c = crc;         /* temporary variable */
    unsigned n;
    uch *in, *out, ch;

    in = window;
    out = &output_data[output_ptr];
    for (n = 0; n < outcnt; n++) {
	    ch = *out++ = *in++;
	    c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
    }
    crc = c;
    bytes_out += (ulg)outcnt;
    output_ptr += (ulg)outcnt;
    outcnt = 0;
}

static void
error(char *x)
{
	puts("\n\n");
	puts(x);
	puts("\n\n -- System halted\n");

	while(1);	/* Halt */
}

void
setup_normal_output_buffer()
{
	output_data = (char *)KERNEL_LOAD_ADR;
}

static inline void
serial_setup(reg_scope_instances regi_ser)
{
	reg_ser_rw_xoff xoff;
	reg_ser_rw_tr_ctrl tr_ctrl;
	reg_ser_rw_rec_ctrl rec_ctrl;
	reg_ser_rw_tr_baud_div tr_baud;
	reg_ser_rw_rec_baud_div rec_baud;

	/* Turn off XOFF. */
	xoff = REG_RD(ser, regi_ser, rw_xoff);

	xoff.chr = 0;
	xoff.automatic = regk_ser_no;

	REG_WR(ser, regi_ser, rw_xoff, xoff);

	/* Set baudrate and stopbits. */
	tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl);
	rec_ctrl = REG_RD(ser, regi_ser, rw_rec_ctrl);
	tr_baud = REG_RD(ser, regi_ser, rw_tr_baud_div);
	rec_baud = REG_RD(ser, regi_ser, rw_rec_baud_div);

	tr_ctrl.stop_bits = 1;	/* 2 stop bits. */

	/*
	 * The baudrate setup is a bit fishy, but in the end the transceiver is
	 * set to 4800 and the receiver to 115200. The magic value is
	 * 29.493 MHz.
	 */
	tr_ctrl.base_freq = regk_ser_f29_493;
	rec_ctrl.base_freq = regk_ser_f29_493;
	tr_baud.div = (29493000 / 8) / 4800;
	rec_baud.div = (29493000 / 8) / 115200;

	REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl);
	REG_WR(ser, regi_ser, rw_tr_baud_div, tr_baud);
	REG_WR(ser, regi_ser, rw_rec_ctrl, rec_ctrl);
	REG_WR(ser, regi_ser, rw_rec_baud_div, rec_baud);
}

void
decompress_kernel()
{
	char revision;

	/* input_data is set in head.S */
	inbuf = input_data;

#ifdef CONFIG_ETRAX_DEBUG_PORT0
	serial_setup(regi_ser0);
#endif
#ifdef CONFIG_ETRAX_DEBUG_PORT1
	serial_setup(regi_ser1);
#endif
#ifdef CONFIG_ETRAX_DEBUG_PORT2
	serial_setup(regi_ser2);
#endif
#ifdef CONFIG_ETRAX_DEBUG_PORT3
	serial_setup(regi_ser3);
#endif

	setup_normal_output_buffer();

	makecrc();

	__asm__ volatile ("move $vr,%0" : "=rm" (revision));
	if (revision < 32)
	{
		puts("You need an ETRAX FS to run Linux 2.6/crisv32.\n");
		while(1);
	}

	puts("Uncompressing Linux...\n");
	gunzip();
	puts("Done. Now booting the kernel.\n");
}