Redistribute the library code; initial work on generic chainloader

5 files changed, 600 insertions, 320 deletions

diff --git a/sample/Makefile b/sample/Makefile
index 900acbd6..fcb8f4c7 100644
--- a/sample/Makefile
+++ b/sample/Makefile
@@ -27,11 +27,11 @@ OBJCOPY    = objcopy
 PPMTOLSS16 = 	../ppmtolss16
 LIB	   = libcom32.a
 
-LIBOBJS	   = conio.o
+LIBOBJS	   = conio.o atou.o printf.o
 
 .SUFFIXES: .lss .c .o .elf .c32
 
-all: syslogo.lss comecho.com hello.c32 hello2.c32 filetest.c32 c32echo.c32 fd.c32
+all: syslogo.lss comecho.com hello.c32 hello2.c32 filetest.c32 c32echo.c32 fd.c32 chain.c32
 
 %.o: %.S
 	$(CC) $(SFLAGS) -c -o $@ $<
diff --git a/sample/atou.c b/sample/atou.c
new file mode 100644
index 00000000..0ea1bfe4
--- /dev/null
+++ b/sample/atou.c
@@ -0,0 +1,23 @@
+static inline int
+isdigit(int ch)
+{
+  return (ch >= '0') && (ch <= '9');
+}
+
+unsigned int skip_atou(const char **s)
+{
+  int i=0;
+  
+  while (isdigit(**s))
+    i = i*10 + *((*s)++) - '0';
+  return i;
+}
+
+unsigned int atou(const char *s)
+{
+  unsigned int i = 0;
+  while (isdigit(*s))
+    i = i*10 + (*s++ - '0');
+  return i;
+}
+
diff --git a/sample/chain.c b/sample/chain.c
new file mode 100644
index 00000000..21a0ab88
--- /dev/null
+++ b/sample/chain.c
@@ -0,0 +1,269 @@
+#ident "$Id$"
+/* ----------------------------------------------------------------------- *
+ *   
+ *   Copyright 2003 H. Peter Anvin - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
+ *   Bostom MA 02111-1307, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * hd.c
+ *
+ * Chainload a hard disk (currently rather braindead.)
+ *
+ * Usage: hd disk# [partition]
+ *
+ * ... e.g. "hd 0 1" will boot the first partition on the first hard disk.
+ *
+ * Only partitions 1-4 supported at this time; 0 = boot MBR (default.)
+ */
+
+#include <com32.h>
+#define NULL ((void *)0)
+
+int printf(const char *, ...);
+int puts(const char *);
+unsigned int skip_atou(char * const *);
+
+static inline void error(const char *msg)
+{
+  puts(msg);
+}
+
+static inline int isspace(char x)
+{
+  return (x == ' ') || (x >= '\b' && x <= '\r');
+}
+
+/*
+ * Call int 13h, but with retry on failure.  Especially floppies need this.
+ */
+int int13_retry(const com32sys_t *inreg, com32sys_t *outreg)
+{
+  int retry = 6;		/* Number of retries */
+  com32sys_t tmpregs;
+  
+  if ( !outreg ) outreg = &tmpregs;
+
+  while ( retry ) {
+    __com32.cs_intcall(0x13, inreg, outreg);
+    if ( (outreg->eflags.l & 1) == 0 )
+      return 0;			/* CF=0, OK */
+  }
+
+  return -1;			/* Error */
+}
+
+/*
+ * Query disk parameters and EBIOS availability for a particular disk.
+ */
+struct diskinfo {
+  int disk;
+  int head;
+  int sect;
+  int ebios;
+} disk_info;
+
+int get_disk_params(int disk)
+{
+  com32sys_t getparm, parm, getebios, ebios;
+
+  memset(&getparm, 0, sizeof getparm);
+  memset(&getebios, 0, sizeof getebios);
+  memset(&disk_info, 0, sizeof disk_info);
+
+  disk_info.disk = disk;
+
+  if ( disk & 0x80 ) {
+    /* Get disk parameters -- hard drives only */
+    
+    getparm.eax.b[1] = 0x08;
+    getparm.edx.b[0] = disk;
+    if ( int13_retry(&getparm, &parm) )
+      return -1;
+    
+    disk_info.head = parm.edx.b[1]+1;
+    disk_info.sect = parm.ecx.b[0] & 0x3f;
+    
+    /* Get EBIOS support */
+    
+    getebios.eax.w[0] = 0x4100;
+    getebios.edx.b[0] = disk;
+    getebios.ebx.w[0] = 0x55aa;
+    getebios.eflags.b[0] = 0x3;	/* CF set */
+    if ( !int13_retry(&getebios, &ebios) ) {
+      if ( ebios.ebx.w[0] == 0xaa55 &&
+	   (ebios.ecx.b[0] & 1) )
+	disk_info.ebios = 1;
+    }
+  }
+
+  return 0;
+}
+
+/*
+ * Get a disk block; buf is REQUIRED TO BE IN LOW MEMORY.
+ */
+struct ebios_dapa {
+  uint16_t len;
+  uint16_t count;
+  uint16_t off;
+  uint16_t seg;
+  uint64_t lba;
+} *dapa;
+
+int read_sector(void *buf, unsigned int lba)
+{
+  com32sys_t inreg;
+
+  memset(&inreg, 0, sizeof inreg);
+
+  if ( disk_info.ebios ) {
+    dapa->len = sizeof(*dapa);
+    dapa->count = 1;		/* 1 sector */
+    dapa->off = OFFS(buf);
+    dapa->seg = SEG(buf);
+    dapa->lba = lba;
+    
+    inreg.esi.w[0] = OFFS(dapa);
+    inreg.ds       = SEG(dapa);
+    inreg.edx.b[0] = disk_info.disk;
+    inreg.eax.b[1] = 0x42;	/* Extended read */
+  } else {
+    unsigned int c, h, s, t;
+
+    s = (lba % disk_info.sect) + 1;
+    t = lba / disk_info.sect;	/* Track = head*cyl */
+    h = t % disk_info.head;
+    c = t / disk_info.head;
+
+    if ( s > 63 || h > 256 || c > 1023 )
+      return -1;
+
+    inreg.eax.w[0] = 0x0201;	/* Read one sector */
+    inreg.ecx.b[1] = c & 0xff;
+    inreg.ecx.b[0] = s + (c >> 6);
+    inreg.edx.b[1] = h;
+    inreg.edx.b[0] = disk_info.disk;
+    inreg.ebx.w[0] = OFFS(buf);
+    inreg.es       = SEG(buf);
+  }
+  
+  return int13_retry(&inreg, NULL);
+}
+
+
+/* A DOS partition table entry */
+struct part_entry {
+  uint8_t active_flag;		/* 0x80 if "active" */
+  uint8_t start_head;
+  uint8_t start_sect;
+  uint8_t start_cyl;
+  uint8_t ostype;
+  uint8_t end_head;
+  uint8_t end_sect;
+  uint8_t end_cyl;
+  uint32_t start_lba;
+  uint32_t length;
+} __attribute__((packed));
+
+int __start(void)
+{
+  char *mbr, *boot_sector;
+  struct part_entry *partinfo;
+  char *cmdline = __com32.cs_cmdline;
+  int hd, drive, whichpart;
+  static com32sys_t inreg;	/* In bss, so zeroed automatically */
+  int retry;
+
+  /* Parse command line */
+  while ( isspace(*cmdline) )
+    cmdline++;
+
+  hd = 0;
+  if ( (cmdline[0] == 'h' || cmdline[0] == 'f') &&
+       cmdline[1] == 'd' ) {
+    hd = cmdline[0] == 'h';
+    cmdline += 2;
+  }
+  drive = (hd ? 0x80 : 0) | skip_atou(&cmdline);
+  whichpart = 0;		/* Default */
+
+  if ( isspace(*cmdline) ) {
+    while ( isspace(*cmdline) )
+      cmdline++;
+
+    whichpart = skip_atou(&cmdline);
+  }
+
+  if ( !(drive & 0x80) && whichpart != 0 ) {
+    error("Partitions not supported on floppy drives\n");
+    goto bail;
+  }
+
+  /* Divvy up the bounce buffer.  To keep things sector-
+     aligned, give the EBIOS DAPA the first sector, then
+     the MBR next, and the rest is used for the partition-
+     chasing stack. */
+  dapa = (struct ebios_dapa *)__com32.cs_bounce;
+  mbr  = (char *)__com32.cs_bounce + 512;
+
+  /* Get the MBR */
+  if ( get_disk_params(drive) ) {
+    error("Cannot get disk parameters\n");
+    goto bail;
+  }
+
+  if ( read_sector(mbr, 0) ) {
+    error("Cannot read MBR\n");
+    goto bail;
+  }
+
+  if ( whichpart == 0 ) {
+    /* Boot the MBR */
+    partinfo = NULL;
+    boot_sector = mbr;
+  } else if ( whichpart <= 4 ) {
+    /* Boot a primary partition */
+    partinfo = &((struct part_entry *)(mbr + 0x1be))[whichpart-1];
+    boot_sector = mbr+512;
+  } else {
+    /* Boot a logical partition */
+    error("Logical partitions not implemented yet\n");
+    goto bail;
+  }
+
+  /* Do the actual chainloading */
+  if ( partinfo ) {
+    /* Actually read the boot sector */
+    if ( read_sector(boot_sector, partinfo->start_lba) ) {
+      error("Cannot read boot sector\n");
+      goto bail;
+    }
+
+    /* 0x7BE is the canonical place for the first partition entry. */
+    inreg.esi.w[0] = 0x7be;
+    memcpy((char *)0x7be, partinfo, sizeof(*partinfo));
+  }
+  inreg.eax.w[0] = 0x000d;	/* Clean up and chain boot */
+  inreg.edx.w[0] = 0;		/* Should be 3 for "keeppxe" */
+  inreg.edi.l    = (uint32_t)boot_sector;
+  inreg.ecx.l    = 512;		/* One sector */
+  inreg.ebx.b[0] = drive;	/* DL = drive no */
+
+  __com32.cs_intcall(0x22, &inreg, NULL);
+
+  /* If we get here, badness happened */
+  error("Chainboot failed!\n");
+
+bail:
+  return 255;
+}
+
+
+  
diff --git a/sample/conio.c b/sample/conio.c
index 9126bc7a..24688a9a 100644
--- a/sample/conio.c
+++ b/sample/conio.c
@@ -15,9 +15,6 @@
  * conio.c
  *
  * Output to the screen
- *
- * FIX THIS: Replace printf() implementation with BSD/MIT-licensed one
- * from klibc
  */
 
 #include <com32.h>
@@ -43,6 +40,7 @@ int putchar(int ch)
   return ch;
 }
 
+/* Note: doesn't put '\n' like the stdc version does */
 int puts(const char *s)
 {
   int count = 0;
@@ -55,318 +53,3 @@ int puts(const char *s)
 
   return count;
 }
-
-/*
- * Oh, it's a waste of space, but oh-so-yummy for debugging.  It's just
- * initialization code anyway, so it doesn't take up space when we're
- * actually running.  This version of printf() does not include 64-bit
- * support.  "Live with it."
- *
- * Most of this code was shamelessly snarfed from the Linux kernel, then
- * modified.
- */
-
-static inline int
-isdigit(int ch)
-{
-  return (ch >= '0') && (ch <= '9');
-}
-
-static int skip_atoi(const char **s)
-{
-  int i=0;
-  
-  while (isdigit(**s))
-    i = i*10 + *((*s)++) - '0';
-  return i;
-}
-
-unsigned int atou(const char *s)
-{
-  unsigned int i = 0;
-  while (isdigit(*s))
-    i = i*10 + (*s++ - '0');
-  return i;
-}
-
-static int strnlen(const char *s, int maxlen)
-{
-  const char *es = s;
-  while ( *es && maxlen ) {
-    es++; maxlen--;
-  }
-
-  return (es-s);
-}
-
-#define ZEROPAD	1		/* pad with zero */
-#define SIGN	2		/* unsigned/signed long */
-#define PLUS	4		/* show plus */
-#define SPACE	8		/* space if plus */
-#define LEFT	16		/* left justified */
-#define SPECIAL	32		/* 0x */
-#define LARGE	64		/* use 'ABCDEF' instead of 'abcdef' */
-
-#define do_div(n,base) ({ \
-int __res; \
-__res = ((unsigned long) n) % (unsigned) base; \
-n = ((unsigned long) n) / (unsigned) base; \
-__res; })
-
-static char * number(char * str, long num, int base, int size, int precision
-	,int type)
-{
-  char c,sign,tmp[66];
-  const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
-  int i;
-  
-  if (type & LARGE)
-    digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
-  if (type & LEFT)
-    type &= ~ZEROPAD;
-  if (base < 2 || base > 36)
-    return 0;
-  c = (type & ZEROPAD) ? '0' : ' ';
-  sign = 0;
-  if (type & SIGN) {
-    if (num < 0) {
-      sign = '-';
-      num = -num;
-      size--;
-    } else if (type & PLUS) {
-      sign = '+';
-      size--;
-    } else if (type & SPACE) {
-      sign = ' ';
-      size--;
-    }
-  }
-  if (type & SPECIAL) {
-    if (base == 16)
-      size -= 2;
-    else if (base == 8)
-      size--;
-  }
-  i = 0;
-  if (num == 0)
-    tmp[i++]='0';
-  else while (num != 0)
-    tmp[i++] = digits[do_div(num,base)];
-  if (i > precision)
-    precision = i;
-  size -= precision;
-  if (!(type&(ZEROPAD+LEFT)))
-    while(size-->0)
-      *str++ = ' ';
-  if (sign)
-    *str++ = sign;
-  if (type & SPECIAL) {
-    if (base==8)
-      *str++ = '0';
-    else if (base==16) {
-      *str++ = '0';
-      *str++ = digits[33];
-    }
-  }
-  if (!(type & LEFT))
-    while (size-- > 0)
-      *str++ = c;
-  while (i < precision--)
-    *str++ = '0';
-  while (i-- > 0)
-    *str++ = tmp[i];
-  while (size-- > 0)
-    *str++ = ' ';
-  return str;
-}
-
-/* Forward decl. needed for IP address printing stuff... */
-int sprintf(char * buf, const char *fmt, ...);
-
-int vsprintf(char *buf, const char *fmt, va_list args)
-{
-  int len;
-  unsigned long num;
-  int i, base;
-  char * str;
-  const char *s;
-  
-  int flags;		/* flags to number() */
-  
-  int field_width;	/* width of output field */
-  int precision;		/* min. # of digits for integers; max
-				   number of chars for from string */
-  int qualifier;		/* 'h', 'l', or 'L' for integer fields */
-  
-  for (str=buf ; *fmt ; ++fmt) {
-    if (*fmt != '%') {
-      *str++ = *fmt;
-      continue;
-    }
-    
-    /* process flags */
-    flags = 0;
-  repeat:
-    ++fmt;		/* this also skips first '%' */
-    switch (*fmt) {
-    case '-': flags |= LEFT; goto repeat;
-    case '+': flags |= PLUS; goto repeat;
-    case ' ': flags |= SPACE; goto repeat;
-    case '#': flags |= SPECIAL; goto repeat;
-    case '0': flags |= ZEROPAD; goto repeat;
-    }
-    
-    /* get field width */
-    field_width = -1;
-    if (isdigit(*fmt))
-      field_width = skip_atoi(&fmt);
-    else if (*fmt == '*') {
-      ++fmt;
-      /* it's the next argument */
-      field_width = va_arg(args, int);
-      if (field_width < 0) {
-	field_width = -field_width;
-	flags |= LEFT;
-      }
-    }
-    
-    /* get the precision */
-    precision = -1;
-    if (*fmt == '.') {
-      ++fmt;	
-      if (isdigit(*fmt))
-	precision = skip_atoi(&fmt);
-      else if (*fmt == '*') {
-	++fmt;
-	/* it's the next argument */
-	precision = va_arg(args, int);
-      }
-      if (precision < 0)
-	precision = 0;
-    }
-    
-    /* get the conversion qualifier */
-    qualifier = -1;
-    if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
-      qualifier = *fmt;
-      ++fmt;
-    }
-    
-    /* default base */
-    base = 10;
-    
-    switch (*fmt) {
-    case 'c':
-      if (!(flags & LEFT))
-	while (--field_width > 0)
-	  *str++ = ' ';
-      *str++ = (unsigned char) va_arg(args, int);
-      while (--field_width > 0)
-	*str++ = ' ';
-      continue;
-      
-    case 's':
-      s = va_arg(args, char *);
-      len = strnlen(s, precision);
-      
-      if (!(flags & LEFT))
-	while (len < field_width--)
-	  *str++ = ' ';
-      for (i = 0; i < len; ++i)
-	*str++ = *s++;
-      while (len < field_width--)
-	*str++ = ' ';
-      continue;
-      
-    case 'p':
-      if (field_width == -1) {
-	field_width = 2*sizeof(void *);
-	flags |= ZEROPAD;
-      }
-      str = number(str,
-		   (unsigned long) va_arg(args, void *), 16,
-		   field_width, precision, flags);
-      continue;
-      
-      
-    case 'n':
-      if (qualifier == 'l') {
-	long * ip = va_arg(args, long *);
-	*ip = (str - buf);
-      } else {
-	int * ip = va_arg(args, int *);
-	*ip = (str - buf);
-      }
-      continue;
-      
-    case '%':
-      *str++ = '%';
-      continue;
-      
-      /* integer number formats - set up the flags and "break" */
-    case 'o':
-      base = 8;
-      break;
-      
-    case 'X':
-      flags |= LARGE;
-    case 'x':
-      base = 16;
-      break;
-      
-    case 'd':
-    case 'i':
-      flags |= SIGN;
-    case 'u':
-      break;
-      
-    default:
-      *str++ = '%';
-      if (*fmt)
-	*str++ = *fmt;
-      else
-	--fmt;
-      continue;
-    }
-    if (qualifier == 'l')
-      num = va_arg(args, unsigned long);
-    else if (qualifier == 'h') {
-      num = (unsigned short) va_arg(args, int);
-      if (flags & SIGN)
-	num = (short) num;
-    } else if (flags & SIGN)
-      num = va_arg(args, int);
-    else
-      num = va_arg(args, unsigned int);
-    str = number(str, num, base, field_width, precision, flags);
-  }
-  *str = '\0';
-  return str-buf;
-}
-
-int sprintf(char * buf, const char *fmt, ...)
-{
-  va_list args;
-  int i;
-  
-  va_start(args, fmt);
-  i=vsprintf(buf,fmt,args);
-  va_end(args);
-  return i;
-}
-
-int printf(const char *fmt, ...)
-{
-  char printf_buf[1024];
-  va_list args;
-  int printed;
-
-  va_start(args, fmt);
-  printed = vsprintf(printf_buf, fmt, args);
-  va_end(args);
-
-  puts(printf_buf);
-
-  return printed;
-}
-
diff --git a/sample/printf.c b/sample/printf.c
new file mode 100644
index 00000000..68717f3d
--- /dev/null
+++ b/sample/printf.c
@@ -0,0 +1,305 @@
+/*
+ * Oh, it's a waste of space, but oh-so-yummy for debugging.  It's just
+ * initialization code anyway, so it doesn't take up space when we're
+ * actually running.  This version of printf() does not include 64-bit
+ * support.  "Live with it."
+ *
+ * Most of this code was shamelessly snarfed from the Linux kernel, then
+ * modified.
+ *
+ * FIX THIS: Replace printf() implementation with BSD/MIT-licensed one
+ * from klibc
+ */
+
+#include <stdarg.h>
+
+static inline int
+isdigit(int ch)
+{
+  return (ch >= '0') && (ch <= '9');
+}
+
+unsigned int skip_atou(const char **s);
+unsigned int atou(const char *s);
+
+static int strnlen(const char *s, int maxlen)
+{
+  const char *es = s;
+  while ( *es && maxlen ) {
+    es++; maxlen--;
+  }
+
+  return (es-s);
+}
+
+#define ZEROPAD	1		/* pad with zero */
+#define SIGN	2		/* unsigned/signed long */
+#define PLUS	4		/* show plus */
+#define SPACE	8		/* space if plus */
+#define LEFT	16		/* left justified */
+#define SPECIAL	32		/* 0x */
+#define LARGE	64		/* use 'ABCDEF' instead of 'abcdef' */
+
+#define do_div(n,base) ({ \
+int __res; \
+__res = ((unsigned long) n) % (unsigned) base; \
+n = ((unsigned long) n) / (unsigned) base; \
+__res; })
+
+static char * number(char * str, long num, int base, int size, int precision
+	,int type)
+{
+  char c,sign,tmp[66];
+  const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
+  int i;
+  
+  if (type & LARGE)
+    digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+  if (type & LEFT)
+    type &= ~ZEROPAD;
+  if (base < 2 || base > 36)
+    return 0;
+  c = (type & ZEROPAD) ? '0' : ' ';
+  sign = 0;
+  if (type & SIGN) {
+    if (num < 0) {
+      sign = '-';
+      num = -num;
+      size--;
+    } else if (type & PLUS) {
+      sign = '+';
+      size--;
+    } else if (type & SPACE) {
+      sign = ' ';
+      size--;
+    }
+  }
+  if (type & SPECIAL) {
+    if (base == 16)
+      size -= 2;
+    else if (base == 8)
+      size--;
+  }
+  i = 0;
+  if (num == 0)
+    tmp[i++]='0';
+  else while (num != 0)
+    tmp[i++] = digits[do_div(num,base)];
+  if (i > precision)
+    precision = i;
+  size -= precision;
+  if (!(type&(ZEROPAD+LEFT)))
+    while(size-->0)
+      *str++ = ' ';
+  if (sign)
+    *str++ = sign;
+  if (type & SPECIAL) {
+    if (base==8)
+      *str++ = '0';
+    else if (base==16) {
+      *str++ = '0';
+      *str++ = digits[33];
+    }
+  }
+  if (!(type & LEFT))
+    while (size-- > 0)
+      *str++ = c;
+  while (i < precision--)
+    *str++ = '0';
+  while (i-- > 0)
+    *str++ = tmp[i];
+  while (size-- > 0)
+    *str++ = ' ';
+  return str;
+}
+
+/* Forward decl. needed for IP address printing stuff... */
+int sprintf(char * buf, const char *fmt, ...);
+
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+  int len;
+  unsigned long num;
+  int i, base;
+  char * str;
+  const char *s;
+  
+  int flags;		/* flags to number() */
+  
+  int field_width;	/* width of output field */
+  int precision;		/* min. # of digits for integers; max
+				   number of chars for from string */
+  int qualifier;		/* 'h', 'l', or 'L' for integer fields */
+  
+  for (str=buf ; *fmt ; ++fmt) {
+    if (*fmt != '%') {
+      *str++ = *fmt;
+      continue;
+    }
+    
+    /* process flags */
+    flags = 0;
+  repeat:
+    ++fmt;		/* this also skips first '%' */
+    switch (*fmt) {
+    case '-': flags |= LEFT; goto repeat;
+    case '+': flags |= PLUS; goto repeat;
+    case ' ': flags |= SPACE; goto repeat;
+    case '#': flags |= SPECIAL; goto repeat;
+    case '0': flags |= ZEROPAD; goto repeat;
+    }
+    
+    /* get field width */
+    field_width = -1;
+    if (isdigit(*fmt))
+      field_width = skip_atou(&fmt);
+    else if (*fmt == '*') {
+      ++fmt;
+      /* it's the next argument */
+      field_width = va_arg(args, int);
+      if (field_width < 0) {
+	field_width = -field_width;
+	flags |= LEFT;
+      }
+    }
+    
+    /* get the precision */
+    precision = -1;
+    if (*fmt == '.') {
+      ++fmt;	
+      if (isdigit(*fmt))
+	precision = skip_atou(&fmt);
+      else if (*fmt == '*') {
+	++fmt;
+	/* it's the next argument */
+	precision = va_arg(args, int);
+      }
+      if (precision < 0)
+	precision = 0;
+    }
+    
+    /* get the conversion qualifier */
+    qualifier = -1;
+    if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
+      qualifier = *fmt;
+      ++fmt;
+    }
+    
+    /* default base */
+    base = 10;
+    
+    switch (*fmt) {
+    case 'c':
+      if (!(flags & LEFT))
+	while (--field_width > 0)
+	  *str++ = ' ';
+      *str++ = (unsigned char) va_arg(args, int);
+      while (--field_width > 0)
+	*str++ = ' ';
+      continue;
+      
+    case 's':
+      s = va_arg(args, char *);
+      len = strnlen(s, precision);
+      
+      if (!(flags & LEFT))
+	while (len < field_width--)
+	  *str++ = ' ';
+      for (i = 0; i < len; ++i)
+	*str++ = *s++;
+      while (len < field_width--)
+	*str++ = ' ';
+      continue;
+      
+    case 'p':
+      if (field_width == -1) {
+	field_width = 2*sizeof(void *);
+	flags |= ZEROPAD;
+      }
+      str = number(str,
+		   (unsigned long) va_arg(args, void *), 16,
+		   field_width, precision, flags);
+      continue;
+      
+      
+    case 'n':
+      if (qualifier == 'l') {
+	long * ip = va_arg(args, long *);
+	*ip = (str - buf);
+      } else {
+	int * ip = va_arg(args, int *);
+	*ip = (str - buf);
+      }
+      continue;
+      
+    case '%':
+      *str++ = '%';
+      continue;
+      
+      /* integer number formats - set up the flags and "break" */
+    case 'o':
+      base = 8;
+      break;
+      
+    case 'X':
+      flags |= LARGE;
+    case 'x':
+      base = 16;
+      break;
+      
+    case 'd':
+    case 'i':
+      flags |= SIGN;
+    case 'u':
+      break;
+      
+    default:
+      *str++ = '%';
+      if (*fmt)
+	*str++ = *fmt;
+      else
+	--fmt;
+      continue;
+    }
+    if (qualifier == 'l')
+      num = va_arg(args, unsigned long);
+    else if (qualifier == 'h') {
+      num = (unsigned short) va_arg(args, int);
+      if (flags & SIGN)
+	num = (short) num;
+    } else if (flags & SIGN)
+      num = va_arg(args, int);
+    else
+      num = va_arg(args, unsigned int);
+    str = number(str, num, base, field_width, precision, flags);
+  }
+  *str = '\0';
+  return str-buf;
+}
+
+int sprintf(char * buf, const char *fmt, ...)
+{
+  va_list args;
+  int i;
+  
+  va_start(args, fmt);
+  i=vsprintf(buf,fmt,args);
+  va_end(args);
+  return i;
+}
+
+int printf(const char *fmt, ...)
+{
+  char printf_buf[1024];
+  va_list args;
+  int printed;
+
+  va_start(args, fmt);
+  printed = vsprintf(printf_buf, fmt, args);
+  va_end(args);
+
+  puts(printf_buf);
+
+  return printed;
+}
+