     1                                  ; ****************************************************************************
     2                                  ; mkdir386.s (mkdir1.s) - by Erdogan Tan - 10/03/2022
     3                                  ; ----------------------------------------------------------------------------
     4                                  ; Retro UNIX 386 v1 - makdir -- make a directory
     5                                  ;
     6                                  ; [ Last Modification: 11/03/2022 ]
     7                                  ;
     8                                  ; Derived from (original) UNIX v5 'mkdir.s' (PDP-11 assembly) source Code
     9                                  ; Ref:
    10                                  ; www.tuhs.org (https://minnie.tuhs.org/cgi-bin/utree.pl?file=V5)
    11                                  ; v5root.tar.gz
    12                                  ; ****************************************************************************
    13                                  ; [ v5root.tar - usr/source/s2/mkdir.s (directory archive date: 27-11-1974) ]
    14                                  ;
    15                                  ; Assembler: NASM v2.15
    16                                  ; ((nasm mkdir1.s -l mkdir1.txt -o mkdir1 -Z error.txt))
    17                                  
    18                                  ; 12/01/2022 (Retro UNIX 386 v1.2)
    19                                  ; 13/10/2015
    20                                  
    21                                  ; UNIX v1 system calls
    22                                  _rele 	equ 0
    23                                  _exit 	equ 1
    24                                  _fork 	equ 2
    25                                  _read 	equ 3
    26                                  _write	equ 4
    27                                  _open	equ 5
    28                                  _close 	equ 6
    29                                  _wait 	equ 7
    30                                  _creat 	equ 8
    31                                  _link 	equ 9
    32                                  _unlink	equ 10
    33                                  _exec	equ 11
    34                                  _chdir	equ 12
    35                                  _time 	equ 13
    36                                  _mkdir 	equ 14
    37                                  _chmod	equ 15
    38                                  _chown	equ 16
    39                                  _break	equ 17
    40                                  _stat	equ 18
    41                                  _seek	equ 19
    42                                  _tell 	equ 20
    43                                  _mount	equ 21
    44                                  _umount	equ 22
    45                                  _setuid	equ 23
    46                                  _getuid	equ 24
    47                                  _stime	equ 25
    48                                  _quit	equ 26	
    49                                  _intr	equ 27
    50                                  _fstat	equ 28
    51                                  _emt 	equ 29
    52                                  _mdate 	equ 30
    53                                  _stty 	equ 31
    54                                  _gtty	equ 32
    55                                  _ilgins	equ 33
    56                                  _sleep	equ 34 ; Retro UNIX 8086 v1 feature only !
    57                                  _msg    equ 35 ; Retro UNIX 386 v1 feature only !
    58                                  _sleep	equ 34 ; Retro UNIX 8086 v1 feature only !
    59                                  _msg	equ 35 ; Retro UNIX 386 v1 feature only !
    60                                  _geterr	equ 36 ; Retro UNIX 386 v1 feature only !
    61                                  ; 12/01/2022 - Retro UNIX 386 v1.2
    62                                  ; Retro UNIX 386 v2 system calls
    63                                  _setgid	equ 37
    64                                  _getgid	equ 38
    65                                  _sysver	equ 39 ; (get) Retro Unix 386 version
    66                                  
    67                                  ;;;
    68                                  ESCKey equ 1Bh
    69                                  EnterKey equ 0Dh
    70                                  
    71                                  %macro sys 1-4
    72                                      ; 03/09/2015	
    73                                      ; 13/04/2015
    74                                      ; Retro UNIX 386 v1 system call.		
    75                                      %if %0 >= 2   
    76                                          mov ebx, %2
    77                                          %if %0 >= 3    
    78                                              mov ecx, %3
    79                                              ;%if %0 = 4
    80                                              %if	%0 >= 4 ; 11/03/2022
    81                                  		mov edx, %4   
    82                                              %endif
    83                                          %endif
    84                                      %endif
    85                                      mov eax, %1
    86                                      int 30h	   
    87                                  %endmacro
    88                                  
    89                                  ; Retro UNIX 386 v1 system call format:
    90                                  ; sys systemcall (eax) <arg1 (ebx)>, <arg2 (ecx)>, <arg3 (edx)>
    91                                  
    92                                  ; 11/03/2022
    93                                  ; Note: Above 'sys' macro has limitation about register positions;
    94                                  ;	ebx, ecx, edx registers must not be used after their
    95                                  ;	positions in sys macro.
    96                                  ; for example:
    97                                  ;	'sys _write, 1, msg, ecx' is defective, because
    98                                  ;	 ecx will be used/assigned before edx in 'sys' macro.
    99                                  ; correct order may be:
   100                                  ;	'sys _write, 1, msg, eax ; (eax = byte count)
   101                                  
   102                                  ;-----------------------------------------------------------------
   103                                  ;  text - code
   104                                  ;-----------------------------------------------------------------
   105                                  
   106                                  [BITS 32] ; 32-bit intructions (for 80386 protected mode)
   107                                  
   108                                  [ORG 0] 
   109                                  
   110                                  START_CODE:
   111                                  	sys	_getuid		; sys getuid ; get user id
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76                              <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78                              <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 00000000 B818000000          <1>  mov eax, %1
    86 00000005 CD30                <1>  int 30h
   112                                  	;mov	[uid], eax
   113 00000007 A2[5D010000]            	mov	[uid], al	; mov r0,uid
   114                                  
   115 0000000C 89E6                    	mov	esi, esp	; mov sp,r5		
   116 0000000E AD                      	lodsd	; number of arguments  ; tst (r5)+
   117                                  	;mov	[args], al	; -- (sp) -- dword [esp] --
   118                                  
   119                                  	; temporary - 11/03/2022
   120                                  	; print test message (if argument count = 1)
   121 0000000F 48                      	dec	eax
   122 00000010 7516                    	jnz	short _loop
   123                                  	sys	_msg, test_msg, 255, 0Fh
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 00000012 BB[65010000]        <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 00000017 B9FF000000          <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81 0000001C BA0F000000          <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 00000021 B823000000          <1>  mov eax, %1
    86 00000026 CD30                <1>  int 30h
   124                                  
   125                                  _loop:	; loop:
   126 00000028 AD                      	lodsd	; (next) argument's addr in eax ; tst (r5)+
   127                                  	;dec	byte [args]
   128 00000029 FF0C24                  	dec	dword [esp]	; dec (sp)
   129                                  	;jg	short md_1	; bgt 1f
   130 0000002C 7507                    	jnz	short md_1
   131                                  	sys	_exit		; sys exit
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76                              <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78                              <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 0000002E B801000000          <1>  mov eax, %1
    86 00000033 CD30                <1>  int 30h
   132                                  ;hlt:
   133                                  ;	nop
   134                                  ;	nop
   135                                  ;	jmp	short hlt
   136                                  
   137                                  md_1:	; 1:
   138 00000035 8B1E                    	mov	ebx, [esi]	; mov (r5),r0		
   139 00000037 89DD                    	mov	ebp, ebx	; -- (r5) -- new sub dir name
   140 00000039 BF[92010000]            	mov	edi, buf1	; mov $buf1,r1	
   141 0000003E BA[F6010000]            	mov	edx, buf2	; mov $buf2,r2
   142 00000043 29C9                    	sub	ecx, ecx	; clr r3
   143 00000045 B42F                    	mov	ah, '/'
   144                                  md_2:	; 1:
   145 00000047 8A03                          	mov	al, [ebx]	; movb (r0)+,r4
   146 00000049 08C0                    	or	al, al
   147 0000004B 740D                    	jz	short md_3	; beq 2f
   148 0000004D AA                      	stosb		  	; movb r4,(r1)+	
   149 0000004E 8802                    	mov	[edx], al	; movb r4,(r2)+	
   150 00000050 42                      	inc	edx
   151 00000051 43                      	inc	ebx
   152                                  	;cmp	al, '/'	 	; directory separator
   153 00000052 38E0                    	cmp	al, ah		; cmpb r4,$'/
   154 00000054 75F1                    	jne	short md_2	; bne 1b
   155                                  		; save position of the last dir seperator 
   156 00000056 89D1                    	mov	ecx, edx	; mov r2,r3
   157 00000058 EBED                    	jmp	short md_2	; br 1b
   158                                  md_3:	; 2:
   159                                  	;mov	al, '/'
   160 0000005A 88E0                    	mov	al, ah
   161 0000005C AA                      	stosb		  	; movb $'/,(r1)+
   162 0000005D B02E                    	mov	al, '.'	  	; movb $'.,(r1)+ 
   163 0000005F AA                      	stosb
   164 00000060 28C0                    	sub	al, al ; 0
   165 00000062 8807                    	mov	[edi], al 	; clrb (r1) 	
   166 00000064 C705[61010000]-         	mov	dword [dir], dot ; mov $dot,dir
   166 0000006A [8B010000]         
   167 0000006E 21C9                    	and	ecx, ecx	; tst r3	
   168 00000070 7417                    	jz	short md_4	; beq 1f
   169 00000072 C705[61010000]-         	mov	dword [dir], buf2 ; mov	$buf2,dir
   169 00000078 [F6010000]         
   170 0000007C 8801                    	mov	[ecx], al ; 0	; clrb (r3)
   171 0000007E 81F9[F7010000]          	cmp	ecx, buf2+1	; cmp r3,$buf2+1
   172 00000084 7403                    	je	short md_4	; beq 1f
   173 00000086 49                      	dec	ecx
   174 00000087 8801                    	mov	[ecx], al ; 0 	; clrb -(r3) / ???
   175                                  md_4:	; 1:
   176                                  	;test	word [uid], 0FFFFh ; (Retro UNIX 386 v1.2)
   177                                  	; (Retro UNIX 386 v1.0 & v1.1)
   178 00000089 F605[5D010000]FF        	test	byte [uid], 0FFh ; tstb uid ; (pdp-11 unix v5)
   179 00000090 742F                    	jz	short md_6 	; beq 2f ; root (super user)
   180                                  	sys	_stat, [dir], stbuf
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 00000092 8B1D[61010000]      <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 00000098 B9[5A020000]        <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 0000009D B812000000          <1>  mov eax, %1
    86 000000A2 CD30                <1>  int 30h
   181                                  		; sys stat; dir:..; stbuf / status of parent dir
   182 000000A4 726A                    	jc	short error	; bes error
   183                                  
   184                                  	; inode mode/flags (from sysstat output)
   185                                  	; (Retro UNIX 386 v1 & v1.1 &v1.2)
   186 000000A6 66A1[5C020000]          	mov	ax, [stbuf+2]	; mov stbuf+4,r0
   187                                  				; (pdp-11 unix v5)
   188                                  	; get owner's uid (from sysstat output)
   189                                  	;mov	bx, [stbuf+6]	; (Retro UNIX 386 v1.2)
   190 000000AC 8A1D[5F020000]          	mov	bl, [stbuf+5]	; (Retro UNIX 386 v1.0 & v1.1)
   191                                  	;cmp	bx, [uid]	; (Retro UNIX 386 v1.2)
   192                                  	; (Retro UNIX 386 v1.0 & v1.1)
   193 000000B2 3A1D[5D010000]          	cmp	bl, [uid]	; cmpb uid,stbuf+7 ; (unix v5)
   194 000000B8 7503                    	jne	short md_5	; bne 1f
   195                                  	; owner's r/w/e permissions
   196                                  	;shr	ax, 6		; ash $-6,r0
   197                                  				; ...
   198                                  				; unix v5 inode mode r/w/e bits:
   199                                  				; IEXEC = 40h (execute, owner)
   200                                  				;  bit3 = 08h (execute, group)
   201                                  				;  bit0 = 01h (execute, others)
   202                                  				; IWRITE = 80h (write, owner)
   203                                  				;  bit4 =  10h (write, group)
   204                                  				;  bit1 =  02h (write, others)
   205                                  				; IREAD = 100h (read, owner)
   206                                  				;  bit5 =  20h (read, group)
   207                                  				;  bit2 =  04h (read, others)
   208                                  				;
   209 000000BA C0E802                  	shr	al, 2		; Retro UNIX 386 v1 & v1.1
   210                                  				; unix v1 inode mode r/w/e bits:
   211                                  				; bit 0 = write perm, others, 1
   212                                   	  			; bit 1 = read perm, others, 2
   213                                  				; bit 2 = write perm, owner, 4
   214                                  				; bit 3 = read perm, owner, 8
   215                                  				; bit 4 = executable file, 16
   216                                  				;
   217                                  	;shr	ax, 6		; Retro UNIX 386 v1.2 (& v2)
   218                                  				; unix v7 inode mode r/w/e bits:
   219                                  				; bit 0 = exec perm, others, 1
   220                                   	  			; bit 1 = write perm, others, 2
   221                                  				; bit 2 = read perm, owner, 4
   222                                  				; bit 3 = exec perm, group, 8
   223                                  				; bit 4 = write perm, group, 16
   224                                  				; bit 5 = read perm, group, 32
   225                                  				; bit 6 = exec perm, owner, 64
   226                                  				; bit 7 = write perm, owner, 128
   227                                  				; bit 8 = read perm, owner, 256
   228                                  				; ...
   229                                  md_5:
   230                                  	;ror	al, 1		; ror r0 ; (bit 6 to cf)
   231                                  	;ror	al, 1		; ror r0 ; (bit 7 to cf)
   232                                  	;;ror	al, 2		; bit 7 to cf (for unix v5/v7)				
   233                                  	; (Retro UNIX 386 v1 & v1.1)
   234 000000BD D0C8                    	ror	al, 1		; bit 2 to cf (for unix v1)
   235                                  	; (Retro UNIX 386 v1.2 & v2)
   236                                  	;ror	al, 2		; bit 7 to cf
   237 000000BF 734F                    	jnc	short error	; bcc error
   238                                  				; / no write permission in parent
   239                                  md_6:
   240                                  	;mov	ebx, ebp	; mov (r5),0f
   241                                  	;sys	_mkdir, ebp, 0C1FFh ; Retro UNIX 386 v1.2
   242                                  		; sys makdir; 0:..; 140777; 0
   243                                  		; ...
   244                                  		; 0C1FFh = 140777 (octal) = 1100000111111111b
   245                                  		;	bit15  = allocated flag/bit
   246                                  		;	bit14  = directory flag/bit
   247                                  		;	bit8 to bit0 = r/w/e permissions
   248                                  
   249                                  	sys	_mkdir, ebp, 0C00Fh ; Retro UNIX 386 v1 & v1.1	
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 000000C1 89EB                <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 000000C3 B90FC00000          <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 000000C8 B80E000000          <1>  mov eax, %1
    86 000000CD CD30                <1>  int 30h
   250                                  	
   251                                  		; Retro UNIX 386 v1: (& v1.1)
   252                                  		;	mkdir mode setting: 1100000000001111b 
   253                                  		;	(unixcopy.com sett: 1100000000001110b)
   254                                  		;	bit15 = allocated flag
   255                                  		;	bit14 = directory flag
   256                                  		;	bit13 = file modified flag (not used)
   257                                  		;	bit12 = large file flag
   258                                  		;	bit11 to bit6 are not used
   259                                  		;	bit5  = setuid on execution flag 	
   260                                  		;	bit4  = executable file flag
   261                                  		;	bit3 to bit0 = r/w/e permissions
   262                                  		;
   263                                  		; Retro UNIX 386 v1.2: (& v2) 
   264                                  		;	mkdir mode setting: 1100000111111111b 
   265                                  		;	(unixcopy/unixhdcp: 1100000111101101b)
   266                                  		;	bit15 = regular file (not device) flag
   267                                  		;	bit14 = directory flag
   268                                  		;	bit13 = reserved flag (or char special)
   269                                  		;	bit12 = large file flag
   270                                  		;	bit11 = setuid on execution flag
   271                                  		;	bit10 = setgid on execution flag 
   272                                  		;	bit9  = use extents flag (not used)
   273                                  		;	bit8 to bit0 = r/w/e permissions	 
   274                                  
   275 000000CF 723F                    	jc	short error ; bes error	; / prob already exists
   276                                  	
   277                                  	;mov	ebx, ebp	 ; mov (r5),0f
   278                                  	;movzx	ecx, byte [uid] 
   279                                  	;sys	_chown, ebp
   280                                  	sys	_chown, ebp, [uid] ; sys chown; 0:..; uid:..
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 000000D1 89EB                <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 000000D3 8B0D[5D010000]      <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 000000D9 B810000000          <1>  mov eax, %1
    86 000000DE CD30                <1>  int 30h
   281                                  	;mov	ebx, ebp	 ; mov (r5),0f
   282                                  	sys	_link, ebp, buf1 ; sys link; 0:..; buf1
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 000000E0 89EB                <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 000000E2 B9[92010000]        <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 000000E7 B809000000          <1>  mov eax, %1
    86 000000EC CD30                <1>  int 30h
   283 000000EE 7220                    	jc	short error	 ; bes error
   284 000000F0 B02E                    	mov	al, '.'
   285 000000F2 AA                      	stosb			 ; movb $'.,(r1)+
   286 000000F3 28C0                    	sub	al, al ; 0
   287 000000F5 8807                    	mov	[edi], al	 ; clrb (r1)
   288                                  	;mov	ebx, [dir]	 ; mov dir,0f
   289                                  	sys	_link, [dir], buf1 ; sys link; 0:..; buf1
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 000000F7 8B1D[61010000]      <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 000000FD B9[92010000]        <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 00000102 B809000000          <1>  mov eax, %1
    86 00000107 CD30                <1>  int 30h
   290 00000109 7205                    	jc	short error
   291 0000010B E918FFFFFF              	jmp	_loop ;jnc _loop ; bec loop
   292                                  
   293                                  error:
   294                                  	;sys	_msg, nl, 2, 07h
   295                                  	sys	_write, 1, nl, 2
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 00000110 BB01000000          <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 00000115 B9[88010000]        <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81 0000011A BA02000000          <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 0000011F B804000000          <1>  mov eax, %1
    86 00000124 CD30                <1>  int 30h
   296                                  	
   297 00000126 89EA                    	mov	edx, ebp	; mov (r5),r0
   298                                  				; mov r0,0f
   299                                  				; clr 0f+2
   300                                  err1:	;1:
   301 00000128 F602FF                  	test	byte [edx], 0FFh ; tstb	(r0)+
   302 0000012B 7403                    	jz	short err2	 ; beq 1f
   303 0000012D 42                      	inc	edx		; inc 0f+2
   304 0000012E EBF8                    	jmp	short err1	; br 1b
   305                                  err2:	; 1:
   306 00000130 29EA                    	sub	edx, ebp ; count
   307 00000132 740E                    	jz	short err3
   308                                  	;mov	ebx, 1		; mov $1,r0
   309                                  	;;;sys	_write, ebx, ebp, edx
   310                                  	;;sys	_write, 1, ebp, edx
   311                                  				; sys write; 0:..; ..
   312                                  	sys	_write, 1, ebp
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 00000134 BB01000000          <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 00000139 89E9                <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81                              <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 0000013B B804000000          <1>  mov eax, %1
    86 00000140 CD30                <1>  int 30h
   313                                  	;sys	_msg, ebp, edx, 0Ch
   314                                  err3:
   315                                  	;mov	ebx, 1		; mov $1,r0
   316                                  	sys	_write, 1, ques, 4 ; (SPACE+'?'+CR+LF)
    72                              <1> 
    73                              <1> 
    74                              <1> 
    75                              <1>  %if %0 >= 2
    76 00000142 BB01000000          <1>  mov ebx, %2
    77                              <1>  %if %0 >= 3
    78 00000147 B9[8D010000]        <1>  mov ecx, %3
    79                              <1> 
    80                              <1>  %if %0 >= 4
    81 0000014C BA04000000          <1>  mov edx, %4
    82                              <1>  %endif
    83                              <1>  %endif
    84                              <1>  %endif
    85 00000151 B804000000          <1>  mov eax, %1
    86 00000156 CD30                <1>  int 30h
   317                                  	;sys	_write, 1, ques, 3 ; (' ?'+CR)
   318                                  				; sys write; ques; 3
   319                                  	;sys	_msg, ques, 4, 0Ch
   320                                  
   321 00000158 E9CBFEFFFF              	jmp	_loop		; br loop
   322                                  
   323                                  ;-----------------------------------------------------------------
   324                                  ;  data - initialized data
   325                                  ;-----------------------------------------------------------------
   326                                  
   327                                  ;args:	db 0
   328 0000015D 00000000                uid:	dd 0
   329                                  ;uid:	db 0
   330 00000161 00000000                dir:	dd 0
   331                                  
   332                                  ; ----------------------------------------------------------------
   333                                  
   334                                  test_msg:
   335 00000165 0D0A                    	db  0Dh, 0Ah
   336 00000167 4D4B44495220627920-     	db  'MKDIR by Erdogan TAN - 11/03/2022'
   336 00000170 4572646F67616E2054-
   336 00000179 414E202D2031312F30-
   336 00000182 332F32303232       
   337                                  nl:
   338 00000188 0D0A00                  	db  0Dh, 0Ah, 0
   339                                  
   340 0000018B 2E00                    dot:	db '.', 0
   341 0000018D 203F0D0A                ques:	db ' ?', 0Dh, 0Ah
   342                                  
   343                                  ;-----------------------------------------------------------------
   344                                  ;  bss - uninitialized data
   345                                  ;-----------------------------------------------------------------
   346                                  
   347 00000191 90                      align 2
   348                                  
   349                                  bss_start:
   350                                  
   351                                  ABSOLUTE bss_start
   352                                  
   353 00000192 <res 64h>               buf1:	resb 100 ; new sub directory name/path buffer (make)
   354 000001F6 <res 64h>               buf2:	resb 100 ; parent directory name/path buffer (perms)
   355 0000025A <res 28h>               stbuf:	resb 40 ; sysstat output buffer
   356                                  ;stbuf:	resb 66 ; for Retro UNIX 386 v1.2 (66 byte sysstat data)
   357                                  
   358                                  ; 10/03/2022
   359                                  ;-----------------------------------------------------------------
   360                                  ; Original UNIX v5 - mkdir (utility) source code (mkdir.s)
   361                                  ;		     in PDP-11 (unix) assembly language
   362                                  ;-----------------------------------------------------------------
   363                                  ;/ makdir -- make a directory
   364                                  ;
   365                                  ;	sys	getuid
   366                                  ;	mov	r0,uid
   367                                  ;	mov	sp,r5
   368                                  ;	tst	(r5)+
   369                                  ;
   370                                  ;loop:
   371                                  ;	tst	(r5)+
   372                                  ;	dec	(sp)
   373                                  ;	bgt	1f
   374                                  ;	sys	exit
   375                                  ;1:
   376                                  ;	mov	(r5),r0
   377                                  ;	mov	$buf1,r1
   378                                  ;	mov	$buf2,r2
   379                                  ;	clr	r3
   380                                  ;1:
   381                                  ;	movb	(r0)+,r4
   382                                  ;	beq	2f
   383                                  ;	movb	r4,(r1)+
   384                                  ;	movb	r4,(r2)+
   385                                  ;	cmpb	r4,$'/
   386                                  ;	bne	1b
   387                                  ;	mov	r2,r3
   388                                  ;	br	1b
   389                                  ;2:
   390                                  ;	movb	$'/,(r1)+
   391                                  ;	movb	$'.,(r1)+
   392                                  ;	clrb	(r1)
   393                                  ;	mov	$dot,dir
   394                                  ;	tst	r3
   395                                  ;	beq	1f
   396                                  ;	mov	$buf2,dir
   397                                  ;	clrb	(r3)
   398                                  ;	cmp	r3,$buf2+1
   399                                  ;	beq	1f
   400                                  ;	clrb	-(r3)	/ ???
   401                                  ;1:
   402                                  ;	tstb	uid
   403                                  ;	beq	2f
   404                                  ;	sys	stat; dir:..; stbuf	/ status of parent dir
   405                                  ;	bes	error
   406                                  ;	mov	stbuf+4,r0
   407                                  ;	cmpb	uid,stbuf+7
   408                                  ;	bne	1f
   409                                  ;	ash	$-6,r0
   410                                  ;1:
   411                                  ;	ror	r0
   412                                  ;	ror	r0
   413                                  ;	bcc	error			/ no write permission in parent
   414                                  ;2:
   415                                  ;	mov	(r5),0f
   416                                  ;	sys	makdir; 0:..; 140777; 0
   417                                  ;	bes	error			/ prob already exists
   418                                  ;	mov	(r5),0f
   419                                  ;	sys	chown; 0:..; uid:..
   420                                  ;	mov	(r5),0f
   421                                  ;	sys	link; 0:..; buf1
   422                                  ;	bes	error
   423                                  ;	movb	$'.,(r1)+
   424                                  ;	clrb	(r1)
   425                                  ;	mov	dir,0f
   426                                  ;	sys	link; 0:..; buf1
   427                                  ;	bec	loop
   428                                  ;
   429                                  ;error:
   430                                  ;	mov	(r5),r0
   431                                  ;	mov	r0,0f
   432                                  ;	clr	0f+2
   433                                  ;1:
   434                                  ;	tstb	(r0)+
   435                                  ;	beq	1f
   436                                  ;	inc	0f+2
   437                                  ;	br	1b
   438                                  ;1:
   439                                  ;	mov	$1,r0
   440                                  ;	sys	write; 0:..; ..
   441                                  ;	mov	$1,r0
   442                                  ;	sys	write; ques; 3
   443                                  ;	br	loop
   444                                  ;
   445                                  ;dot:	<.\0>
   446                                  ;ques:	< ?\n>
   447                                  ;	.even
   448                                  ;
   449                                  ;.bss
   450                                  ;buf1:	.=.+100.
   451                                  ;buf2:	.=.+100.
   452                                  ;stbuf:	.=.+40.
   453                                  ;
