Import Dev86src-0.0.8.tar.gzv0.0.8

1 files changed, 537 insertions, 0 deletions

diff --git a/bootblocks/minix.c b/bootblocks/minix.c
new file mode 100644
index 0000000..f6ba7b4
--- /dev/null
+++ b/bootblocks/minix.c
@@ -0,0 +1,537 @@
+/*
+ * This bootblock loads the linux-8086 executable in the file 'linux'
+ * from the root directory of a minix filesystem.
+ *
+ * Copyright (C) 1990-1996 Robert de Bath, distributed under the GPL Version 2
+ * Based on minix filesystem definitions.
+ */
+
+#include <a.out.h>
+
+#undef DOTS		/* define to have dots printed */
+#define zone_shift 0	/* for any < 32M (non-zero not supported yet) */
+
+#define seg_at(k) ((k)*64)
+#define seg_of(p) ((unsigned int)p >>4)
+#define BOOTSEG	  (0x07c0)
+#define LOADSEG   (0x1000)
+
+#asm 
+BOOTSEG  = 0x07c0
+BOOTADDR = 0x7c00
+LOADSEG  = 0x1000	! This must be sector aligned
+
+.text
+! Apparently on startup the only things we can assume are that we start at
+! `start` (ABS addr $07C00) ...
+
+! So first set CS=DS=ES=SS=0
+! The we move this to $0500 and put the stack at the top of the first 64k.
+! The directory 'file' is loaded $1500 and scanned there.
+! The final executable will be loaded in the 2nd 64k chunk.
+!
+org $0500	! The lowest available address.
+start:
+  include sysboot.s
+  org codestart
+
+  xor	ax,ax
+  mov	ds,ax
+  mov	es,ax
+  mov	ss,ax
+  mov	sp,ax
+
+  mov	ax,#$0204		! Read 4 sectors, code + superblock.
+  mov	bx,#start		! Where this _should_ be
+  mov	cx,#$0001		! From sector 1
+  xor	dx,dx			! Of the floppy drive head zero
+  int	$13
+
+  jmpi	code,#0
+
+#endasm
+
+/****************************************************************************/
+/* Super block table.  The root file system and every mounted file system
+ * has an entry here.  The entry holds information about the sizes of the bit
+ * maps and inodes.  The s_ninodes field gives the number of inodes available
+ * for files and directories, including the root directory.  Inode 0 is 
+ * on the disk, but not used.  Thus s_ninodes = 4 means that 5 bits will be
+ * used in the bit map, bit 0, which is always 1 and not used, and bits 1-4
+ * for files and directories.  The disk layout is:
+ *
+ *      Item        # blocks
+ *    boot block      1
+ *    super block     1
+ *    inode map     s_imap_blocks
+ *    zone map      s_zmap_blocks
+ *    inodes        (s_ninodes + 1 + INODES_PER_BLOCK - 1)/INODES_PER_BLOCK
+ *    unused        whatever is needed to fill out the current zone
+ *    data zones    (s_nzones - s_firstdatazone) << s_log_zone_size
+ *
+ * A super_block slot is free if s_dev == NO_DEV. 
+ */
+
+#define BLOCK_SIZE      1024	/* # bytes in a disk block */
+
+/* Flag bits for i_mode in the inode. */
+#define I_TYPE          0170000	/* this field gives inode type */
+#define I_REGULAR       0100000	/* regular file, not dir or special */
+#define I_BLOCK_SPECIAL 0060000	/* block special file */
+#define I_DIRECTORY     0040000	/* file is a directory */
+#define I_CHAR_SPECIAL  0020000	/* character special file */
+#define I_SET_UID_BIT   0004000	/* set effective uid on exec */
+#define I_SET_GID_BIT   0002000	/* set effective gid on exec */
+#define ALL_MODES       0006777	/* all bits for user, group and others */
+#define RWX_MODES       0000777	/* mode bits for RWX only */
+#define R_BIT           0000004	/* Rwx protection bit */
+#define W_BIT           0000002	/* rWx protection bit */
+#define X_BIT           0000001	/* rwX protection bit */
+#define I_NOT_ALLOC     0000000	/* this inode is free */
+
+/* Type definitions */
+typedef unsigned short unshort;	/* must be 16-bit unsigned */
+typedef unshort block_nr;	/* block number */
+typedef unshort inode_nr;	/* inode number */
+typedef unshort zone_nr;	/* zone number */
+typedef unshort bit_nr;		/* if inode_nr & zone_nr both unshort,
+				   then also unshort, else long */
+
+typedef unshort sect_nr;
+
+typedef long zone_type;		/* zone size */
+typedef unshort mask_bits;	/* mode bits */
+typedef unshort dev_nr;		/* major | minor device number */
+typedef char links;		/* number of links to an inode */
+typedef long real_time;		/* real time in seconds since Jan 1, 1970 */
+typedef long file_pos;		/* position in, or length of, a file */
+typedef short uid;		/* user id */
+typedef char gid;		/* group id */
+
+/* Tables sizes */
+#define NR_ZONE_NUMS       9	/* # zone numbers in an inode */
+#define NAME_SIZE         14	/* # bytes in a directory component */
+
+/* Miscellaneous constants */
+#define SUPER_MAGIC   0x137F	/* magic number contained in super-block */
+
+#define BOOT_BLOCK  (block_nr)0	/* block number of boot block */
+#define SUPER_BLOCK (block_nr)1	/* block number of super block */
+#define ROOT_INODE  (inode_nr)1	/* inode number for root directory */
+
+/* Derived sizes */
+#define NR_DZONE_NUM     (NR_ZONE_NUMS-2)		/* # zones in inode */
+#define INODES_PER_BLOCK (BLOCK_SIZE/sizeof(d_inode))	/* # inodes/disk blk */
+#define NR_INDIRECTS     (BLOCK_SIZE/sizeof(zone_nr))	/* # zones/indir blk */
+#define INTS_PER_BLOCK   (BLOCK_SIZE/sizeof(int))	/* # integers/blk */
+
+struct super_block {
+  inode_nr s_ninodes;		/* # usable inodes on the minor device */
+  zone_nr s_nzones;		/* total device size, including bit maps etc */
+  unshort s_imap_blocks;	/* # of blocks used by inode bit map */
+  unshort s_zmap_blocks;	/* # of blocks used by zone bit map */
+  zone_nr s_firstdatazone;	/* number of first data zone */
+  short s_log_zone_size;	/* log2 of blocks/zone */
+  file_pos s_max_size;		/* maximum file size on this device */
+  short s_magic;		/* magic number to recognize super-blocks */
+
+} ;
+
+/* Type definitions local to the File System. */
+typedef struct {		/* directory entry */
+  inode_nr d_inum;		/* inode number */
+  char d_name[NAME_SIZE];	/* character string */
+} dir_struct;
+
+/* Declaration of the disk inode used in rw_inode(). */
+typedef struct {		/* disk inode.  Memory inode is in "inotab.h" */
+  mask_bits i_mode;		/* file type, protection, etc. */
+  uid i_uid;			/* user id of the file's owner */
+  file_pos i_size;		/* current file size in bytes */
+  real_time i_modtime;		/* when was file data last changed */
+  gid i_gid;			/* group number */
+  links i_nlinks;		/* how many links to this file */
+  zone_nr i_zone[NR_ZONE_NUMS];	/* block nums for direct, ind, and dbl ind */
+} d_inode;
+
+/****************************************************************************/
+
+#ifdef zone_shift
+#if zone_shift == 0
+#define load_zone load_block
+#endif
+#else
+static short     zone_shift;
+#endif
+
+/* The name of the file and inode to start */
+extern char bootfile[];
+extern inode_nr inode;
+
+/* For multi-sector reads */
+extern sect_nr lastsect;
+extern sect_nr firstsect;
+extern unsigned loadaddr;
+extern unsigned loadcount;
+
+/* Keep track of zones to load */
+extern zone_nr * next_zone;
+extern zone_nr * end_zone;
+extern zone_nr   indirect;
+
+/* Where to load zones */
+extern unsigned ldaddr;
+
+/* Directory reading */
+extern dir_struct * dirptr;
+extern unsigned flength;
+
+/* The 'shape' of the floppy - intuit from superblock */
+extern unsigned n_sectors;
+
+/*
+ * #define b_super	(*(struct super_block *) 1024)
+ * #define b_inode	((d_inode *)2048)
+ * #define b_zone	((zone_nr *)3072)
+ */
+
+extern struct super_block b_super;
+extern d_inode            b_inode[INODES_PER_BLOCK];
+extern zone_nr            b_zone[NR_INDIRECTS];
+extern dir_struct         directory[];
+
+/****************************************************************************/
+
+#asm
+! A few variables we need to know the positions of for patching, so export
+! them and as86_encaps will make some variables.
+.text
+export	_inode			! Inode to search
+_inode: .word	1		! ROOT_INODE
+
+export	_bootfile		! File to boot, make this whatever you like,
+_bootfile:			! 'boot' is good too.
+   .ascii	"linux"
+   .byte	0,0,0,0,0,0,0,0,0
+
+_loadcount: .word	0
+_firstsect: .word	0
+_loadaddr:  .word	0
+_lastsect:  .word	0
+
+code:
+  call	_loadprog
+  call	_runprog
+  br	_nogood
+#endasm
+
+static
+load_block(address, blkno)
+unsigned address, blkno;
+{
+   register sect_nr sectno;
+   if(blkno == 0) { zero_block(address); return; }
+#ifdef DOTS
+   bios_putc('.');
+#endif
+
+   sectno = (sect_nr)blkno * 2;
+   load_sect(address,    sectno);
+   load_sect(address+32, sectno+1);
+}
+
+static
+load_sect(address, sectno)
+unsigned address;
+sect_nr sectno;
+{
+   register sect_nr nsect;
+
+   nsect   =  sectno%n_sectors +1;
+   sectno /= n_sectors;
+   nsect  |= (sectno<<8);
+
+   if( loadcount )
+   {
+      lastsect++;
+      if( ( address & 4095 ) && nsect == lastsect )
+      {
+         loadcount++;
+         return;
+      }
+      get_now();
+   }
+
+   lastsect  = firstsect = nsect;
+   loadaddr  = address;
+   loadcount = 1;
+}
+
+static
+get_now()
+{
+#asm
+  xor	dx,dx
+  mov	cx,[_firstsect]
+  shr	ch,#1
+  adc	dh,#0
+  mov	es,[_loadaddr]
+  xor	bx,bx
+  mov	ax,[_loadcount]
+  test	ax,ax
+  jz	no_load
+  mov	ah,#2
+  int	$13
+  jc	nogood
+no_load:
+  xor	ax,ax
+  mov	[_loadcount],ax
+#endasm
+}
+
+#asm
+nogood:
+  j _nogood
+#endasm
+
+static
+zero_block(address)
+{
+#asm
+#if __FIRST_ARG_IN_AX__
+  mov	es,ax
+#else
+  mov	bx,sp
+  mov	es,[bx+2]
+#endif
+  push	di
+  mov	cx,#512
+  xor	ax,ax
+  mov	di,ax
+  rep
+   stosw
+  pop	di
+#endasm
+}
+
+#ifndef load_zone
+NOT_DEFINED_load_zone(address, zoneno)
+{
+}
+#endif
+
+#ifdef DOTS
+static
+bios_putc(c)
+{
+#asm
+#if !__FIRST_ARG_IN_AX__
+  mov	bx,sp
+  mov	ax,[bx+2]
+#endif
+  mov	ah,#$0E
+  mov	bx,#7
+  int	$10
+#endasm
+}
+#endif
+
+static
+nogood()
+{
+/* This didn't work, chain the boot sector of the HD */
+#asm
+  push	cs
+  pop	es
+hcode:
+  mov	ax,#$0201		! Read 1 sector
+  mov	bx,#BOOTADDR		! In the boot area
+  mov	cx,#$0001		! From sector 1
+  mov	dx,#$0080		! Of the hard drive head zero
+  int	$13
+  jc	hcode			! Keep trying forever!
+  jmpi	BOOTADDR,0
+#endasm
+}
+
+#asm
+end_of_part1:
+  if *>start+0x200
+     fail
+  endif
+  .blkb	0x200+start-*
+#endasm
+
+static
+loadprog()
+{
+#ifdef DOTS
+   bios_putc('+');
+#endif
+   if( b_super.s_magic != SUPER_MAGIC ) nogood();
+   n_sectors = b_super.s_nzones / 80;
+   if( n_sectors < 5 ) n_sectors = b_super.s_nzones / 40;
+
+try_again:;
+#ifdef zone_shift
+   if( zone_shift != b_super.s_log_zone_size) nogood();
+#else
+   zone_shift = b_super.s_log_zone_size;
+#endif
+
+   inode--;
+   load_block(seg_of(b_inode), inode/INODES_PER_BLOCK
+                          + b_super.s_imap_blocks
+                          + b_super.s_zmap_blocks
+                          + 2);
+   get_now();
+
+   ldaddr = LOADSEG;		/* Load at 64k mark */
+
+   {
+      register d_inode * i_ptr;
+      i_ptr = b_inode + inode%INODES_PER_BLOCK;
+      next_zone = i_ptr->i_zone;
+      flength   = i_ptr->i_size;
+      if( (i_ptr->i_mode & I_TYPE) == I_DIRECTORY )
+      {
+	 ldaddr = seg_of(directory);
+	 inode  = 0;		/* Mark - we've no _file_ inode yet */
+      }
+   }
+
+   end_zone = next_zone+NR_DZONE_NUM;
+   load_zone(seg_of(b_zone), (indirect = next_zone[NR_DZONE_NUM]));
+   get_now();
+
+   for(;;)
+   {
+      if( next_zone >= end_zone )
+      {
+         if( indirect != 0 )
+         {
+            next_zone = b_zone;
+            end_zone  = next_zone + NR_INDIRECTS;
+            indirect  = 0;
+            continue;
+         }
+	 break;
+      }
+      load_zone(ldaddr, *next_zone);
+      next_zone++;
+      ldaddr += (seg_at(1) << zone_shift);
+   }
+   get_now();
+
+#ifdef DOTS
+   bios_putc('\r');
+   bios_putc('\n');
+#endif
+   if(!inode)
+   {
+#ifdef DOTS
+      bios_putc('+');
+#endif
+      dirptr = directory;
+      while(flength > 0)
+      {
+register char * s = bootfile;
+register char * p = dirptr->d_name;
+
+	 if( dirptr->d_inum )
+	 {
+	    for(;;)
+	    {
+	       if( *s == '\0')
+	       {
+		  if(*p == '\0')
+		  {
+		     inode = dirptr->d_inum;
+		     goto try_again;
+		  }
+		  break;
+	       }
+	       if( *s++ != *p++ ) break;
+	    }
+	 }
+	 flength -= 16;
+	 dirptr++;
+      }
+      nogood();
+   }
+}
+
+static
+runprog()
+{
+/* This did work, run the loaded executable */
+#asm
+  xor	dx,dx		! DX=0 => floppy drive
+  push	dx		! CX=0 => partition offset = 0
+  mov	si,[_n_sectors]	! Save for monitor.out
+
+  mov	bx,#LOADSEG
+  mov	ds,bx		! DS = loadaddress
+  inc	bx
+  inc	bx		! bx = initial CS
+  xor	di,di		! Zero
+  mov	ax,[di]
+  cmp	ax,#0x0301	! Right magic ?
+  bne	nogood		! Yuk ...
+  mov	ax,[di+2]
+  and	ax,#$20		! Is it split I/D ?
+  jz	impure		! No ...
+  mov	cl,#4
+  mov	ax,[di+8]
+  shr	ax,cl
+impure:
+  pop	cx
+  add	ax,bx
+  mov	ss,ax
+  mov	sp,[di+24]	! Chmem value
+  mov	ds,ax
+
+  push	bx
+  push	di		!  jmpi	0,#LOADSEG+2
+  retf
+#endasm
+}
+
+#asm
+! These functions are pulled from the C library.
+libstuff:
+imodu:
+	xor	dx,dx
+	div	bx
+	mov	ax,dx		! instruction queue full so xchg slower
+	ret
+idiv_u:
+	xor	dx,dx
+	div	bx
+	ret
+libend:
+
+vars:
+_n_sectors:	.word 0
+_next_zone:	.word 0
+_end_zone:	.word 0
+_indirect:	.word 0
+_ldaddr:	.word 0
+_dirptr:	.word 0
+_flength:	.word 0
+varend:
+
+end_of_prog:
+  if *>start+0x400
+     fail
+  endif
+
+  .blkb	0x3FF+start-*
+  .byte 0xFF
+
+_b_super:	.blkb 1024
+_b_inode:	.blkb 1024
+_b_zone:	.blkb 1024
+_directory:	.blkb 32768
+
+#endasm