kvisc/vm/ob/command.k

# 1 "command.k"
# 1 "<built-in>"
# 1 "<command-line>"
# 31 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 32 "<command-line>" 2
# 1 "command.k"
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

cmdstart:
    jmp start

# 1 "crt/crt.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; Limits
;
# 31 "crt/crt.k"
;
; Magic numbers
;




;
; CRT librairies
;

# 1 "./crt/sys.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; SHUTDOWN syscall
;
; End virtual machine
;
Sys.Shutdown := 0x00

;
; EXIT syscall
;
; Return to COMMAND.COM
;
Sys.Exit := 0x01

;
; EXEC syscall
;
; IN
; ax0 = new RIP to load
; ax1 = frame ID to switch to
;
; New frame ID must be higher than current
; frame ID, and cannot be below 5
;
; New CR1 is set so that new RIP corresponds to 1MB
;
Sys.ExecuteInFrame := 0x02

; FIND syscalls
;
; Find file on disk
;
; IN
; ax0 = address of name buffer
; ax1 = size of name buffer
;
; OUT
; rax = # of bytes written in name buffer
; rdx = size of file
;
;
Sys.FindFirst := 0x20
Sys.FindNext := 0x21

;
; OPEN syscall
;
; IN
; ax0 = name string
;
; OUT
; rax = handle of file, or <0 if couldn't open
;
Sys.OpenFile := 0x30

;
; CREATE syscall
;
; IN
; ax0 = name string
;
; OUT
; rax = 0 on success, or <0 if couldn't open
;
Sys.CreateFile := 0x31

;
; REMOVE syscall
;
; IN
; ax0 = name string
;
; OUT
; rax = 0 on success, or <0 if couldn't open
;
Sys.RemoveFile := 0x32

;
; CLOSE syscall
;
; IN
; ax0 = file handle
;
Sys.CloseFile := 0x35

;
; READ syscall
;
; IN
; ax0 = file handle
; ax1 = buffer address
; ax2 = buffer size
;
; OUT
; rax = number of bytes read, <0 on error
;
Sys.ReadFile := 0x38

; Halt mode
Sys.EnterHaltMode := 0x999
# 43 "crt/crt.k" 2
# 1 "./crt/str.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; int strnlen(char *, int)
;
strnlen:
    mov ecx, ax1
    scasb ax0, zero

    sub eax, ax1, ecx
    ret

;
; int strlen(char *)
;
strlen:
    mov ecx, 0x7AFFFFFF
    mov edx, ecx
    scasb ax0, zero

    sub eax, edx, ecx
    ret

;
; void strcpy(char *, const char *)
;
strcpy:
.l:
    mov ecx, b[ax1]
    mov b[ax0], ecx

    jecxz .r

    inc ax0
    inc ax1

    jmp .l

.r:
    ret

;
; void strncpy(char *, const char *, int)
;
strncpy:
    mov ecx, ax2
    jecxz .r

.l:
    mov b[ax0], b[ax1]

    inc ax0
    inc ax1

    loop .l

.r:
    ret

;
; void strnzcpy(char *, const char *, int)
;
strnzcpy:
    mov ecx, ax2
    jecxz .r

.l:
    mov eax, b[ax1]
    mov b[ax0], eax

    jeaxz .r

    inc ax0
    inc ax1

    loop .l

.z:
    nul b[ax0]

.r:
    ret

;
; int strcmp(const char *str1, const char *str2)
;
; Returns:
; 0 if the contents of both strings are equal
; >0 if the first character that does not match has a greater value in str1 than in str2
; <0 if the first character that does not match has a lower value in str1 than in str2
;
strcmp:
    nul esi
.l:
    movzx eax, b[ax0+esi]
    movzx edx, b[ax1+esi]

    bne eax, edx, .r

    ; both zero?
    add ecx, eax, edx
    jecxz .r

    inc esi
    jmp .l

.r:
    sub eax, edx
    ret

;
; int strncmp(const char *str1, const char *str2, int maxn)
;
strncmp:
    mov ecx, ax2
    jecxz .r

.l:
    movzx eax, b[ax0]
    movzx edx, b[ax1]

    bne eax, edx, .r

    inc ax0
    inc ax1
    loop .l

.r:
    sub eax, edx
    ret

;
; char *strchrnul(const char *str, int ch)
;
strchrnul:
    mov ecx, 0x7AFFFFFF
    scasb ax0, ax1

    mov eax, ax0
    ret

;
; char *strchr(const char *str, int ch)
;
strchr:
    mov ecx, 0x7AFFFFFF
    scasb ax0, ax1

    bnz b[ax0], .r
    nul eax
    ret

.r:
    mov eax, ax0
    ret

;
; void strrev(char *buf, const char *str)
;
; buf and src must NOT overlap
;
strrev:
    bzr b[ax1], .z

    ; save str's location
    mov esi, ax1

    ; go to str's end, just before
    ; the null terminator
    mov ecx, 0x7AFFFFFF
    scasb ax1, zero
    dec ax1

.l:
    ; copy, going backward though str
    ; and forward through buf
    mov b[ax0], b[ax1]

    beq ax1, esi, .r

    inc ax0
    dec ax1
    jmp .l

.r:
    nul b[ax0+1]
    ret

.z:
    nul b[ax0]
    ret

;
; void strrev2(char *str)
;
; Inverses str
;
strrev2:
    bzr b[ax0], .r

    mov ax1, ax0

    ; go to str's end, just before
    ; the null terminator
    mov ecx, 0x7AFFFFFF
    scasb ax1, zero
    dec ax1

    ; increase ax0 while decreasing ax1, performing exchanges
.l:
    blteu ax1, ax0, .r

    xchg b[ax0], b[ax1]

    inc ax0
    dec ax1
    jmp .l

.r:
    ret
# 44 "crt/crt.k" 2
# 1 "./crt/mem.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; void memcpy(void *, const void *, int)
;
memcpy:
    mov ecx, ax2
    jecxz .r

.l:
    sub edx, ax2, ecx
    mov b[ax0+edx], b[ax1+edx]
    loop .l

.r:
    ret

;
; void memzero(void *, int)
;
memzero:
    mov ecx, ax1
    jecxz .r

.l:
    nul b[ax0]
    inc ax0
    loop .l

.r:
    ret
# 45 "crt/crt.k" 2
# 1 "./crt/time.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; struct TIME
; {
; byte sec; +0 (0-59)
; byte min; +1 (0-59)
; byte hour; +2 (0-23)
; byte mday; +3 (0-31)
; byte month; +4 (0-11)
; byte; +5 (pad)
; word year; +6 (0-65536)
; word yday; +8 (0-365)
; word; +10 (pad)
; dword; +12 (pad)
; } 16 bytes
;

;
; int DaysInYear(int year)
;
DaysInYear:
    mov eax, 365

    ; divisible by 4?
    rem ecx, ax0, 4
    jecxnz .end

    ; divisible by 100?
    rem ecx, ax0, 100
    jecxnz .leap

    ; divisible by 400?
    rem ecx, ax0, 400
    jecxnz .end

.leap:
    inc eax

.end:
    ret

;
; TIME *GetTimeUTC(void)
;
GetTimeUTC:
    ytime

    mov edi, .buf

    ; seconds
    rem esi, eax, 60
    mov b[edi], esi

    ; minutes
    div esi, eax, 60
    rem esi, 60
    mov b[edi+1], esi

    ; hours
    div esi, eax, 3600
    rem esi, 24
    mov b[edi+2], esi

    ; month days
    div esi, eax, 3600*24
    mov b[edi+3], esi

    ; month
    mov b[edi+4], rbx

    ; years
    mov w[edi+6], ecx

    ;
    ; ydays (TODO)
    ;

    mov eax, .buf
    ret

.buf = [24]
# 46 "crt/crt.k" 2

# 1 "./crt/fmt/ltostr.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; void itoa(char *buf, int num, int base)
;
itoa:
    mov ax3, 1
    jmp ltostr

;
; void utoa(char *buf, int num, int base)
;
utoa:
    nul ax3
    jmp ltostr

;
; void ltostr(char *buf, int num, int base, bool signed)
;
ltostr:
    mov eax, ax0
    nul ecx

    ; make sure base is in [2, 32]
    bltu ax2, 2, .bad
    bltu 36, ax2, .bad

    ; deal with zero
    bzr ax1, .is_zero

    ; deal with base 10 signedness

    bzr ax3, .conv
    bne ax2, 10, .conv ; base 10

    shr ecx, ax1, 63 ; extract ax1 sign
    jecxz .conv

    neg ax1 ; NEG if negative

    ; main loop
.conv:
    bzr ax1, .fini

    rem edx, ax1, ax2 ; ax1 % base

    blt 9, edx, .nondec ; edx > 9 ?

    add edx, '0'
    jmp .next

.nondec:
    add edx, 55 ; 'A' - 10

.next:
    mov b[ax0], edx

    inc ax0

    div ax1, ax2
    jmp .conv

    ; add minus flag, null-terminate and reverse
.fini:
    jecxz .cxz
    mov b[ax0], '-'
    inc ax0

.cxz:
    nul b[ax0]

    call strrev2, eax
    ret

;
; exceptional cases
;
.bad:
    mov b[ax0], 0
    ret

.is_zero:
    mov b[ax0], 48 ; '0'
    mov b[ax0+1], 0
    ret
# 48 "crt/crt.k" 2
# 1 "./crt/fmt/strtol.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; int strtol(const char *str, int base)
;
; eax = integer extracted from str
; edx = pointer to first invalid byte
;
strtol:
    mov ax2, 1
    jmp strtoq

;
; int strtoul(const char *str, int base)
;
; eax = integer extracted from str
; edx = pointer to first invalid byte
;
strtoul:
    nul ax2
    jmp strtoq

;
; int strtoq(const char *str, int base, bool signed)
;
; guesses base when 'base'=0
;
strtoq:
    nul eax, esi
    mov edx, ax0

    ; make sure base is in [2, 32]
    beq ax1, 1, .bad
    bltu 36, ax1, .bad

    ; empty string?
    bzr b[edx], .done

.skip_spc:
    bne b[edx], ' ', .no_spc
    inc edx
    jmp .skip_spc

.no_spc:
    ; skip +
    bne b[edx], '+', .no_plus
    inc edx

.no_plus:
    ; unsigned?
    bzr ax2, .unsigned

    ; parse '-'
    bne b[edx], '-', .unsigned
    inc edx
    mov esi, 1

.unsigned:
    ; base 0
    bzr ax1, .base_0

    ; base prefix?
    bne b[edx], '0', .main_loop

    inc edx
    movzx ecx, b[edx]

    ; "0x"/"0b" prefix
    jecxz .done ; "0"
    beq ecx, 'x', .parsed_0x
    beq ecx, 'b', .parsed_0b

    ; may be octal, but we don't care
    ; we accept "0110101010" (despite base=2) for instance
    jmp .main_loop

.parsed_0x:
    ; are we in base 16?
    ; if not, leave eax = 0 and *edx = 'x'
    bne ax1, 16, .done
    ; else
    inc edx
    jmp .main_loop

.parsed_0b:
    ; are we in base 2?
    ; if not, leave eax = 0 and *edx = 'b'
    bne ax1, 2, .done
    ; else
    inc edx
    jmp .main_loop

.base_0:
    ; guess base

    beq b[edx], '0', .b0_not10

    ; must be base 10
    mov ax1, 10
    jmp .main_loop

.b0_not10:
    inc edx

    bne b[edx], 'x', .b0_not16
    inc edx
    mov ax1, 16
    jmp .main_loop

.b0_not16:
    bne b[edx], 'b', .b0_not2
    inc edx
    mov ax1, 2
    jmp .main_loop

.b0_not2:
    ; take octal by default
    mov ax1, 8

.main_loop:
    movzx ecx, b[edx]
    inc edx

    ; between 0 and 9?
    bltu ecx, '0', .done
    bltu '9', ecx, .not_digit10

    ; yes
    sub ecx, '0'
    jmp .next

.not_digit10:
    bltu ecx, 'A', .done
    bltu 'Z', ecx, .not_digitAZ

    sub ecx, 55 ; 'A' - 10
    jmp .next

.not_digitAZ:
    bltu ecx, 'a', .done
    bltu 'z', ecx, .done

    sub ecx, 87 ; 'a' - 10
    jmp .next

.next:
    ; too large for base?
    blteu ax1, ecx, .done

    mul eax, ax1
    add eax, ecx
    jmp .main_loop

.done:
    ; negative?
    bzr esi, .r

    ; yes
    neg eax

.r:
    ret

.bad:
    ret
# 49 "crt/crt.k" 2
# 1 "./crt/fmt/doprnt.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; typedef int (*PUTC)(int ch)
; int doprnt(PUTC putc, int n, const char *fmt, va_list ap)
;
doprnt:
    push ebp
    mov ebp, esp

    push nx0, nx1, nx2
    push nx3, nx4, nx5

    mov nx0, ax2 ; fmt
    mov nx2, ax3 ; va_list
    mov nx3, ax1 ; n
    mov nx5, ax0 ; putc
    nul nx4 ; return value

.main_loop:
    ; find '%' or null-terminator
    mov ecx, 0x7AFFFFFF
    mov nx1, nx0
    scasb nx1, '%'

    ; everything below nx1 is a regular character; print it
.print_regular:
    beq nx0, nx1, .check_modf

    call .doput, b[nx0]

    inc nx0
    jmp .print_regular

.check_modf:
    ; did we find a '%' ?
    ; if not, then we found fmt's null-terminator; we're done
    bne b[nx0], '%', .epilogue

    ; we did find a modifier / '%'
    mov eax, b[nx0+1]
    add nx0, 2

    beq eax, 's', .modf_s
    beq eax, 'c', .modf_c
    beq eax, 'p', .modf_p
    beq eax, 'x', .modf_x
    beq eax, 'd', .modf_d
    beq eax, 'o', .modf_o
    beq eax, 'b', .modf_b
    beq eax, '%', .modf_percent

    ; unrecognized
    jmp .bad_modifier

.modf_s:
    ; get string address
    mov nx1, q[nx2]
    add nx2, 8

    bzr nx1, .nullstring

.print_string:
    movzx ax0, b[nx1]
    bzr ax0, .main_loop

    inc nx1
    call .doput

    jmp .print_string

.modf_c:
    call .doput, q[nx2]
    add nx2, 8

    jmp .main_loop

.modf_p:
    call .doput, '0'
    call .doput, 'x'
    ; Fallthrough

.modf_x:
    mov ax2, 16
    jmp .print_number

.modf_d:
    mov ax2, 10
    jmp .print_number

.modf_o:
    mov ax2, 8
    jmp .print_number

.modf_b:
    mov ax2, 2
    jmp .print_number

.print_number:
    ; allocate itoa conversion buffer
    sub esp, 80
    mov nx1, esp

    ; assume modifier already set up ax2
    call itoa, esp, q[nx2]
    add nx2, 8

.print_itoa_buf:
    movzx ax0, b[nx1]

    bzr ax0, .pib_end_loop
    inc nx1

    call .doput
    jmp .print_itoa_buf

.pib_end_loop:
    add esp, 80
    jmp .main_loop

.modf_percent:
    call .doput, '%'
    jmp .main_loop

.bad_modifier:
    ; print "%?" to clearly indicate that something is wrong
    call .doput, '%'
    call .doput, '?'

    jmp .main_loop

.nullstring:
    ; %s was passed a NULL
    call .doput, '('
    call .doput, 'n'
    call .doput, 'u'
    call .doput, 'l'
    call .doput, 'l'
    call .doput, ')'

    jmp .main_loop

.epilogue:
    mov eax, nx4

    pop nx5, nx4
    pop nx3, nx2
    pop nx1, nx0

    leave
    ret
;
; prints ax0
;
.doput:
    ; update print count
    inc nx4

    ; if n==0, don't print
    ; we follow the C convention that sprintf()-like functions
    ; should return the number of characters that would have
    ; been printed/written if 'n' were big enough
    bzr nx3, .r

    ; decrement n and print
    dec nx3
    call nx5

    ; did putc fail?
    jeaxz .r

    ; yes, so artificially set n=0
    nul nx3

.r:
    ret
# 50 "crt/crt.k" 2
# 1 "./crt/fmt/printf.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

;
; int putc(int ch)
;
putc:
    prn ax0
    nul eax
    ret

;
; int printf(const char *fmt, ...)
;
printf:
    mov ax2, ax0
    mov ax0, putc
    mov ax1, 0x7AFFFFFF
    add ax3, esp, 8
    jmp doprnt

;
; int nprintf(const char *fmt, int n, ...)
;
nprintf:
    mov ax2, ax0
    mov ax0, putc
    add ax3, esp, 8
    jmp doprnt

;
; Print a string
; Guaranteed to only affect ecx and ax0
;
print:
.l:
    movzx eax, b[ax0]
    jeaxz .r

    prn eax
    inc ax0

    jmp .l

.r:
    ret

;
; Print exactly ax1 characters
;
nprint:
    mov ecx, ax1
    jecxz .r

.l:
    prn b[ax0]
    inc ax0
    loop .l

.r:
    ret
# 51 "crt/crt.k" 2

exit:
    mov eax, Sys.Exit
    trap 0

abort:
    crash
# 8 "command.k" 2




; COMMAND.COM guarantees that programs
; are always loaded on a 16KB boundary
; This is guaranteed to be the case
; in all future veesions as well


start:
    mov esp, 0x104000
    mov ebp, zero

    call main

    mov eax, Sys.EnterHaltMode
    trap 0

    crash

cmd.veesionstr = "COMMAND.COM, veesion 0.1 (KVISC)\nCopyright (C) 2019, The OS/K Team\nMIT license (permissive), see LICENCE file in source tree"

argbuf.size := 256
argbuf = [argbuf.size]
argv0 = [argbuf.size]
argv1pos = 0

stdin_echoing = 1

prompt = [32]

main:
    mov esi, prompt
    mov b[esi+0], 'C'
    mov b[esi+1], ':'
    mov b[esi+2], '\'
    mov b[esi+3], '>'
    mov b[esi+4], ' '

.print_prompt:
    call print, prompt

    ; empty stuff
    call memzero, argbuf, argbuf.size
    call memzero, argv0, argbuf.size
    nul q[argv1pos]

    ; call nprint, argv0, argbuf.size

    ; iterator through argbuf
    nul ecx

.input_loop:
    pause
    pause
    pause

    ; Fill .buf with user input
    scan eax
    jeaxz .input_loop

    ; ESC key pressed?
    beq eax, 0x1B, .handle_EXIT

    ; backspace character?
    bne eax, 8, .handle_input

    ; anything to delete?
    jecxz .input_loop ; no

    ; yes, delete it
    dec ecx
    add edx, ecx, argbuf
    nul b[edx]

    ; update screen
    bzr b[stdin_echoing], .input_loop
    prn 8

    jmp .input_loop

.handle_input:
    bzr b[stdin_echoing], .se.z
    prn eax

.se.z:
    beq eax, 10, .extract_argv0

    ; when max line length is reached,
    ; force a newline
    beq ecx, argbuf.size, .extract_argv0

    ; add character to buffer and increase iterator (ecx)
    add edx, ecx, argbuf
    mov b[edx], eax
    inc ecx

    ; another one
    jmp .input_loop

.extract_argv0:
    ; did we read anything at all?
    ; if not, just go back to waiting input
    jecxz .print_prompt

    ; find first whitespace or null-terminator
    mov ecx, argbuf.size
    mov edx, argbuf
    scasb edx, ' '

    ; argv1 exists? if so, save its position
    mov esi, edx

.next_space:
    mov ecx, b[esi]
    jecxz .do_extract

    ; skip spaces
    bne ecx, ' ', .not_a_space
    inc esi
    jmp .next_space

.not_a_space:
    ; if we're here, we found a
    ; non-zero non-space character
    mov q[argv1pos], esi

    ; fallthrough

.do_extract:
    ; how much do we copy?
    sub ecx, edx, argbuf
    jecxz .detect_builtin
    dec ecx

    mov edi, argbuf
    mov esi, argv0

.copy_loop:
    mov b[esi], b[edi]

    inc edi
    inc esi

    loop .copy_loop

.detect_builtin:

.builtin_cls = "cls"
    call strcmp, argv0, .builtin_cls
    jeaxz .handle_CLS

.builtin_crash = "crash"
    call strcmp, argv0, .builtin_crash
    jeaxz .handle_CRASH

.builtin_date = "date"
    call strcmp, argv0, .builtin_date
    jeaxz .handle_DATE

.builtin_dir = "dir"
    call strcmp, argv0, .builtin_dir
    jeaxz .handle_DIR

.builtin_dump = "dump"
    call strcmp, argv0, .builtin_dump
    jeaxz .handle_DUMP

.builtin_echo = "echo"
    call strcmp, argv0, .builtin_echo
    jeaxz .handle_ECHO

.builtin_erase = "erase"
    call strcmp, argv0, .builtin_erase
    jeaxz .handle_ERASE

.builtin_exit = "exit"
    call strcmp, argv0, .builtin_exit
    jeaxz .handle_EXIT

.builtin_help = "help"
    call strcmp, argv0, .builtin_help
    jeaxz .handle_HELP

.builtin_halt = "halt"
    call strcmp, argv0, .builtin_halt
    jeaxz .handle_HALT

.builtin_make = "make"
    call strcmp, argv0, .builtin_make
    jeaxz .handle_MAKE

.builtin_print = "print"
    call strcmp, argv0, .builtin_print
    jeaxz .handle_PRINT

.builtin_prompt = "prompt"
    call strcmp, argv0, .builtin_prompt
    jeaxz .handle_PROMPT

.builtin_remove = "remove"
    call strcmp, argv0, .builtin_remove
    jeaxz .handle_REMOVE

.builtin_time = "time"
    call strcmp, argv0, .builtin_time
    jeaxz .handle_TIME

.builtin_vers = "vers"
    call strcmp, argv0, .builtin_vers
    jeaxz .handle_VERS

    jmp .try_exec

;
; call builtins
;

# 1 "usr/cmd-dir.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.



.handle_DIR:
    push ebp
    mov ebp, esp

    push nx0, nx1
    push nx2, nx3

    nul nx0 ; no. of files found
    nul nx1 ; no. of directories found
    nul nx2 ; total amount of bytes found

    call print, .dirmsg

.dir_first:
    mov eax, Sys.FindFirst
    mov ax0, .dir_buf
    mov ax1, 0x80
    trap 0

    jmp .dir_list

.dir_next:
    mov eax, Sys.FindNext
    mov ax0, .dir_buf
    mov ax1, 0x80
    trap 0

.dir_list:
    jeaxz .dir_end

    mov nx3, ecx ; file size
    add nx2, ecx

    ; directory?
    bnz edx, .dir_is_dir

    ; found a file
    inc nx0

    ; separate extension from file name
    mov ecx, 0x80
    mov esi, .dir_buf
    mov edi, esi
    scasb esi, '.'

    ; print file name
    sub ax1, esi, edi
    dec ax1
    call nprint, edi

    ; calculate where to put extension
    sub edi, esi, .dir_buf
    dec edi

.dir_ext_pad:
    ; print at least 11 non-space characters before extension
    blte 11, edi, .dir_print_ext
    prn ' '
    inc edi
    jmp .dir_ext_pad

.dir_print_ext:
    prn ' '
    ; here we print at least 4 characters excluding '.'
    mov ecx, 4

    bne b[esi], '.', .dir_print_ext.1
    inc esi

.dir_print_ext.1:
    bzr b[esi], .dir_print_ext.2

    ; print and decrease ecx, unless it's already 0
    prn b[esi]
    inc esi
    jecxz .dir_print_ext.1

    dec ecx
    jmp .dir_print_ext.1

.dir_print_ext.2:
    ; did we print at least 4 bytes?
    jecxz .dir_print_bytes ; yes, carry on

.dir_pe2.l:
    prn ' '
    loop .dir_pe2.l

.dir_print_bytes:
    ; print file size in bytes
    prn ' '
    prn ' '
    prn ' '

    shr eax, nx3, 10
    and nx3, 1023

    push nx3, eax
    call printf, .dir_bytesstr
    add esp, 16

.dir_prepare_next:
    ; go find next entry
    prn 10
    jmp .dir_next

.dir_end:
    shr eax, nx2, 10
    shr edx, eax, 10
    and eax, 1023
    and nx2, 1023

    push nx2, eax, edx
    call printf, .dir_endstr0
    add esp, 24

    push nx1, nx0
    call printf, .dir_endstr1
    add esp, 16

    pop nx3, nx2
    pop nx1, nx0

    leave
    jmp .print_prompt

    ; special case: direcory
.dir_is_dir:
    inc nx1

    ; use printf instead of print
    ; because it returns the # of
    ; printed characters
    call printf, .dir_buf

    blte 11, eax, .dir_no_pad
    sub ecx, 11, eax
    dec ecx

.dir.l:
    prn ' '
    loop .dir.l

.dir_no_pad:
    call print, .dir_ext

    jmp .dir_print_bytes

.dir_buf = [0x80]
.dir_ext = " <DIR> "
.dir_endstr0 = "             total %dMB + %dKB + %dB\n"
.dir_endstr1 = "             found %d file(s), %d dir(s)\n"
.dirmsg = "Directory of C:\\\n\n"

.dir_bytesstr = "%d kilobytes + %d bytes"
; .dir_bytesstr = "%dMB + %dKB + %dB" # too soon
# 228 "command.k" 2
# 1 "usr/cmd-exec.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

.try_exec:
    ; try without appending ".com"
    mov eax, Sys.OpenFile
    mov ax0, argv0
    trap 0

    ; we good?
    blte zero, eax, .do_exec

    ; nope, append ".com" and try again
    sub ecx, argbuf.size, 5
    scasb ax0, zero ; find null-term
    mov b[ax0+0], '.' ; ".com"
    mov b[ax0+1], 'c'
    mov b[ax0+2], 'o'
    mov b[ax0+3], 'm'
    nul b[ax0+4]

    ; try again
    mov eax, Sys.OpenFile
    mov ax0, argv0
    trap 0

    ; still no good?
    bltz eax, .exec_not_found

.do_exec:
    ; load file into memory
    mov ax0, eax
    mov ax1, 0x108000
    mov ax2, 0x8000
    mov eax, Sys.ReadFile
    trap 0

    ; save load address
    mov ecx, eax

    ; close file
    mov eax, Sys.CloseFile
    trap 0

    ; read anything?
    bltz ecx, .couldnt_read
    jecxz .empty_file

    ; all good, let's go
    mov eax, Sys.ExecuteInFrame
    mov ax0, 0x108000
    mov ax1, 5
    trap 0

    ; unreachable
    jmp abort
# 229 "command.k" 2
# 1 "usr/cmd-fsmisc.k" 1
; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

.handle_ERASE:
    mov eax, Sys.RemoveFile
    mov ax0, q[argv1pos]
    bzr ax0, .need_params
    trap 0

    bltz eax, .couldnt_remove

    jmp .handle_MAKE ; re-create it back

.handle_MAKE:
    mov eax, Sys.CreateFile
    mov ax0, q[argv1pos]
    bzr ax0, .need_params
    trap 0

    bltz eax, .couldnt_open

    jmp .print_prompt

.handle_PRINT:
    mov eax, Sys.OpenFile
    mov ax0, q[argv1pos]
    bzr ax0, .need_params
    trap 0

    bltz eax, .file_not_found

    mov ax0, eax
    mov ax1, 0x108000
    mov ax2, 0x8000

    mov eax, Sys.ReadFile
    trap 0

    mov ecx, eax

    mov eax, Sys.CloseFile
    trap 0

    bltz ecx, .couldnt_read
    jecxz .empty_file

    call nprint, 0x108000, ecx

    jmp .print_prompt

.handle_REMOVE:
    mov eax, Sys.RemoveFile
    mov ax0, q[argv1pos]
    bzr ax0, .need_params
    trap 0

    bltz eax, .couldnt_remove

    jmp .print_prompt
# 230 "command.k" 2

.handle_CLS:
    prn 0x8BF00001
    jmp .print_prompt

.handle_CRASH:
    jmp abort

.handle_DATE:
    call GetTimeUTC

    mov ecx, b[eax+4]
    inc ecx

    push b[eax+3], ecx, w[eax+6]
    call printf, .datefmt
    add esp, 40

    jmp .print_prompt

.datefmt = "%d/%d/%d\n"

.handle_DUMP:
    dump
    jmp .print_prompt

.handle_ECHO:
    mov eax, q[argv1pos]
    jeaxz .echo.end

    call print, eax

.echo.end:
    prn 10
    jmp .print_prompt

.handle_EXIT:
    mov eax, Sys.Shutdown
    trap 0
    jmp .print_prompt

.handle_HALT:
    mov eax, Sys.EnterHaltMode
    trap 0
    jmp .print_prompt

.handle_PROMPT:
    mov ax0, prompt
    mov ax1, q[argv1pos]
    bzr ax1, .need_params
    call strcpy

    jmp .print_prompt

.handle_TIME:
    call GetTimeUTC

    push b[eax], b[eax+1], b[eax+2]
    call printf, .timefmt
    add esp, 24

    jmp .print_prompt

.timefmt = "%d:%d:%d\n"

.handle_VERS:
    call print, cmd.veesionstr
    prn 10

    jmp .print_prompt

.handle_HELP:
    call print, .helpmsg
    call print, .helpmsg.cls
    call print, .helpmsg.date
    call print, .helpmsg.dir
    call print, .helpmsg.dump
    call print, .helpmsg.echo
    call print, .helpmsg.erase
    call print, .helpmsg.exit
    call print, .helpmsg.help
    call print, .helpmsg.halt
    call print, .helpmsg.make
    call print, .helpmsg.print
    call print, .helpmsg.prompt
    call print, .helpmsg.remove
    call print, .helpmsg.time
    call print, .helpmsg.ver

    jmp .print_prompt

.helpmsg = "The following commands are built-in:\n"
.helpmsg.cls = "    CLS        Clear screen\n"
.helpmsg.date = "    DATE       Display current date\n"
.helpmsg.dir = "    DIR        Print contents of current directory\n"
.helpmsg.dump = "    DUMP       Toggles debug instruction dumping\n"
.helpmsg.echo = "    ECHO       Write arguments to standard output\n"
.helpmsg.erase = "    ERASE      Clear a file, making it blank\n"
.helpmsg.exit = "    EXIT       Initiate machine shutdown\n"
.helpmsg.help = "    HELP       Display these messages\n"
.helpmsg.halt = "    HALT       Put processor in halt mode\n"
.helpmsg.make = "    MAKE       Create an empty file\n"
.helpmsg.print = "    PRINT      Display contents of text file\n"
.helpmsg.prompt = "    PROMPT     Change the command line prompt\n"
.helpmsg.remove = "    REMOVE     Delete a file (permanently)\n"
.helpmsg.time = "    TIME       Display current time of day\n"
.helpmsg.ver = "    VERS       Display current COMMAND.COM veesion\n"

.exec_not_found:
    push argv0
    call printf, .enf_errmsg
    add esp, 8

    jmp .print_prompt

.enf_errmsg = "%s: file not found\n"

.file_not_found:
    push q[argv1pos], argv0
    call printf, .fnf_errmsg
    add esp, 16

    jmp .print_prompt

.fnf_errmsg = "%s: %s: file not found\n"

.empty_file:
    push q[argv1pos], argv0
    call printf, .ef_errmsg
    add esp, 16

    jmp .print_prompt

.ef_errmsg = "%s: %s: file was empty\n"

.couldnt_open:
    push q[argv1pos], argv0
    call printf, .cno_errmsg
    add esp, 16

    jmp .print_prompt

.cno_errmsg = "%s: %s: an error occured while opening file\n"

.couldnt_remove:
    push q[argv1pos], argv0
    call printf, .cne_errmsg
    add esp, 16

    jmp .print_prompt

.cne_errmsg = "%s: %s: an error occured while removing file\n"

.couldnt_read:
    push q[argv1pos], argv0
    call printf, .cnr_errmsg
    add esp, 16

    jmp .print_prompt

.cnr_errmsg = "%s: %s: an error occured while reading file\n"

.need_params:
    call print, argv0
    call print, .np_errmsg

    jmp .print_prompt

.np_errmsg = ": need more parameters\n"