ppc

as/k-as.py

@@ -27,7 +27,7 @@ b_text = TemporaryFile(mode="w+b")
 
 lst_instrs = open(os.path.join(sys.path[0], "instrs.lst"))
 
-main_src = open(sys.argv[1])
+source = open(sys.argv[1])
 b_out = open(sys.argv[3], "wb")
 b_sym = open(sys.argv[4], "w")
 
@@ -42,7 +42,6 @@ def leave(i):
     b_sym.close()
     b_data.close()
     b_text.close()
-    main_src.close()
     lst_instrs.close()
     sys.exit(i)
 
@@ -124,59 +123,6 @@ def arith_eval(s):
 
 #-------------------------------------------------------------------------------
 
-inc_depth = 0
-inc_depth_max = 16
-
-# Quickly goes through source file and resolves "include" directives ONLY
-def do_includes(fi):
-    global inc_depth
-    global pcurfile
-
-    for _, line in enumerate(fi):
-        line = line.rstrip()
-        tok = line.split(None, 1)
-
-        if len(tok) == 0:
-            continue
-
-        if tok[0] == "include":
-            if len(tok) == 1:
-                print("Missing parameter for include directive")
-                leave(1)
-
-            if tok[1][0] not in "'\"" or tok[1][-1] != tok[1][0]:
-                print("Invalid format for include directive: {}".format(line))
-                leave(1)
-
-            old_curf = pcurfile
-            pcurfile = tok[1][1:-1]
-
-            try:
-                new_fi = open(pcurfile, "r")
-
-            except:
-                print("Couldn't open file: {}".format(line))
-                leave(1)
-
-            inc_depth += 1
-            if inc_depth >= inc_depth_max:
-                print("Maximal include depth reached: {}".format(line))
-                leave(1)
-
-            source.write("$file: {}:\n".format(pcurfile.replace(' ', '')))
-            do_includes(new_fi)
-            pcurfile = old_curf
-            source.write("$file: {}:\n".format(pcurfile.replace(' ', '')))
-            
-
-        else:
-            source.write("{}\n".format(line))
-
-    inc_depth -= 1
-
-
-#-------------------------------------------------------------------------------
-
 def parse():
     global ptext
     global pcurfile
@@ -191,10 +137,14 @@ def parse():
         if len(line) == 0:
             continue
 
-        # len("$file: ") == 7
+        if line[0] == '#':
-        if len(line) > 7 and line[:7] == "$file: ":
+            tok = line.split()
-            pcurfile = line[7:]
+
-            continue
+            if len(tok) < 3:
+                print("Invalid # directive: {}".format(line))
+                leave(-1)
+
+            pcurfile = tok[2][1:-1]
 
         quote = False
         for i in range(len(line)):
@@ -371,31 +321,13 @@ def parse_preproc(line):
 #-------------------------------------------------------------------------------
 
 fmts = {
-    "r":        0b00000000,
+    "r":        0b00000000, "m_r":      0b00100000, "m_rr":     0b01000000,    
-    "m_r":      0b00100000,
+    "m_rriw":   0b01100000, "m_rrid":   0b10000000, "m_rrii":   0b10100000,
-    "m_rr":     0b01000000,
+    "m_riq":    0b11000000, "imm8":     0b11100001, "imm16":    0b11100010,
-    "m_rriw":   0b01100000,
+    "imm32":    0b11100100, "imm64":    0b11101000,
-    "m_rrid":   0b10000000,
-    "m_rrii":   0b10100000,
-    "m_riq":    0b11000000,
-    "imm8":     0b11100001,
-    "imm16":    0b11100010,
-    "imm32":    0b11100100,
-    "imm64":    0b11101000,
 }
 
-pref2len = {
+pref2len = { "b" : 1, "w" : 2, "d" : 4, "l" : 4, "q" : 8 }
-    "b" : 1,
-    "w" : 2,
-    "d" : 4,
-    "l" : 4,
-    "q" : 8,
-}
-
-i_aliases = {
-    "inc_2" : "add_2",
-    #"dec_2" : "sub_2",
-}
 
 def parse_instr(line):
     if line == None or len(line) == 0:
@@ -423,9 +355,6 @@ def parse_instr(line):
 
     instr_name += "_{}".format(len(tok))
 
-    if instr_name in i_aliases:
-        instr_name = i_aliases[instr_name]
-
     #
     # Parse operands
     #
@@ -778,7 +707,6 @@ def genout():
 #-------------------------------------------------------------------------------
 
 parse_lst_instrs()
-do_includes(main_src)
 parse()
 gentext()
 genout()

ka/Makefile

@@ -8,12 +8,11 @@ KSDIR=../vm/ob
 KPDIR=../vm/ob
 
 KSRC = $(shell ls *.k)
-KPPC = $(patsubst %.k,$(KODIR)/%.ppc,$(KSRC))
 KCOM = $(patsubst %.k,$(KODIR)/%.com,$(KSRC))
 
 $(KODIR)/%.com: %.k
-	@cpp -I. -x assembler-with-cpp $< > $(patsubst %.k,$(KODIR)/%.ppc,$<)
+	@cpp -I. -x assembler-with-cpp $< > $(KSDIR)/$<
-	@../as/k-as.py $(patsubst %.k,$(KODIR)/%.ppc,$<) 0x100000 $@ $(patsubst %.k,$(KSDIR)/%.sym,$<)
+	@../as/k-as.py $(KSDIR)/$< 0x100000 $@ $(patsubst %.k,$(KSDIR)/%.sym,$<)
 
 dos: $(KCOM)
 

ka/command.k

@@ -243,7 +243,7 @@ main:
 
     push b[rax+3], rcx, w[rax+6]
     call printf, .datefmt
-    inc rsp, 40
+    add rsp, 40
 
     jmp .print_prompt
 
@@ -286,7 +286,7 @@ main:
 
     push b[rax], b[rax+1], b[rax+2]
     call printf, .timefmt
-    inc rsp, 24
+    add rsp, 24
 
     jmp .print_prompt
 
@@ -338,7 +338,7 @@ main:
 .exec_not_found:
     push argv0
     call printf, .enf_errmsg
-    inc rsp, 8
+    add rsp, 8
 
     jmp .print_prompt
 
@@ -347,7 +347,7 @@ main:
 .file_not_found:
     push q[argv1pos], argv0
     call printf, .fnf_errmsg
-    inc rsp, 16
+    add rsp, 16
 
     jmp .print_prompt
 
@@ -356,7 +356,7 @@ main:
 .empty_file:
     push q[argv1pos], argv0
     call printf, .ef_errmsg
-    inc rsp, 16
+    add rsp, 16
 
     jmp .print_prompt
 
@@ -365,7 +365,7 @@ main:
 .couldnt_open:
     push q[argv1pos], argv0
     call printf, .cno_errmsg
-    inc rsp, 16
+    add rsp, 16
 
     jmp .print_prompt
 
@@ -374,7 +374,7 @@ main:
 .couldnt_remove:
     push q[argv1pos], argv0
     call printf, .cne_errmsg
-    inc rsp, 16
+    add rsp, 16
 
     jmp .print_prompt
 
@@ -383,7 +383,7 @@ main:
 .couldnt_read:
     push q[argv1pos], argv0
     call printf, .cnr_errmsg
-    inc rsp, 16
+    add rsp, 16
 
     jmp .print_prompt
 

ka/crt/fmt/doprnt.k

@@ -30,7 +30,7 @@ doprnt:
 
     call .doput, b[r12]
 
-    inc r12, 1
+    inc r12
     jmp .print_regular
 
 .check_modf:
@@ -40,7 +40,7 @@ doprnt:
 
     ; we did find a modifier / '%'
     mov rax, b[r12+1]
-    inc r12, 2
+    add r12, 2
 
     beq rax, 's', .modf_s
     beq rax, 'c', .modf_c
@@ -57,7 +57,7 @@ doprnt:
 .modf_s:
     ; get string address
     mov r13, q[r14]
-    inc r14, 8
+    add r14, 8
 
     bzr r13, .nullstring
 
@@ -72,7 +72,7 @@ doprnt:
 
 .modf_c:
     call .doput, q[r14]
-    inc r14, 8
+    add r14, 8
 
     jmp .main_loop
 
@@ -104,7 +104,7 @@ doprnt:
 
     ; assume modifier already set up ax2
     call itoa, rsp, q[r14]
-    inc r14, 8
+    add r14, 8
 
 .print_itoa_buf:
     movzx ax0, b[r13]
@@ -116,7 +116,7 @@ doprnt:
     jmp .print_itoa_buf
 
 .pib_end_loop:
-    inc rsp, 80
+    add rsp, 80
     jmp .main_loop
 
 .modf_percent:

ka/crt/fmt/ltostr.k

@@ -47,11 +47,11 @@ ltostr:
 
     blt 9, rdx, .nondec     ; rdx > 9 ?
 
-    inc rdx, '0'
+    add rdx, '0'
     jmp .next
 
 .nondec:
-    inc rdx, 55     ; 'A' - 10
+    add rdx, 55     ; 'A' - 10
 
 .next:
     mov b[ax0], rdx

ka/crt/fmt/strtol.k

@@ -80,7 +80,7 @@ strtoq:
     ; if not, leave rax = 0 and *rdx = 'x'
     bne ax1, 16, .done
     ; else
-    inc rdx, 1
+    inc rdx
     jmp .main_loop
 
 .parsed_0b:
@@ -149,7 +149,7 @@ strtoq:
     blteu ax1, rcx, .done
 
     mul rax, ax1
-    inc rax, rcx
+    add rax, rcx
     jmp .main_loop
 
 .done:

ka/crt/time.k

@@ -36,7 +36,7 @@ DaysInYear:
     jrcxnz .end
 
 .leap:
-    inc rax, 1
+    inc rax
 
 .end:
     ret

ka/sys/intr/common.k

@@ -29,7 +29,7 @@ ScreenOfDeath:
 .do_print:
     push r14, r12
     call printf, .scr2
-    inc rsp, 24
+    add rsp, 24
 
     call dumprf, r14
     prn 10

ka/sys/intr/trap0.k

@@ -167,27 +167,27 @@ DefaultTrapHandler:
 ; Disk API
 ;
 .handle_FindFirst:
-    inc ax0, r12
+    add ax0, r12
     call DISK.FindFirst
     jmp .fini.savecx
 
 .handle_FindNext:
-    inc ax0, r12
+    add ax0, r12
     call DISK.FindNext
     jmp .fini.savecx
 
 .handle_OpenFile:
-    inc ax0, r12
+    add ax0, r12
     call DISK.OpenFile
     jmp .fini
 
 .handle_CreateFile:
-    inc ax0, r12
+    add ax0, r12
     call DISK.CreateFile
     jmp .fini
 
 .handle_RemoveFile:
-    inc ax0, r12
+    add ax0, r12
     call DISK.RemoveFile
     jmp .fini
 
@@ -196,7 +196,7 @@ DefaultTrapHandler:
     jmp .fini
 
 .handle_ReadFile:
-    inc ax1, r12
+    add ax1, r12
     call DISK.ReadFile
     jmp .fini
 

ka/usr/cmd-dir.k

@@ -1,7 +1,7 @@
 ; The OS/K Team licenses this file to you under the MIT license.
 ; See the LICENSE file in the project root for more information.
 
-N := 11
+#define N 11
 
 .handle_DIR:
     push rbp
@@ -34,7 +34,7 @@ N := 11
     jraxz .end
 
     mov r15, rcx ; file size
-    inc r14, rcx
+    add r14, rcx
 
     ; directory?
     bnz rdx, .is_dir
@@ -102,7 +102,7 @@ N := 11
 
     push r15, rax
     call printf, .bytesstr
-    inc rsp, 16
+    add rsp, 16
 
 .prepare_next:
     ; go find next entry
@@ -117,11 +117,11 @@ N := 11
 
     push r14, rax, rdx
     call printf, .endstr0
-    inc rsp, 24
+    add rsp, 24
 
     push r13, r12
     call printf, .endstr1
-    inc rsp, 16
+    add rsp, 16
 
     pop r15, r14
     pop r13, r12
@@ -134,8 +134,8 @@ N := 11
     inc r13
 
     ; use printf instead of print
-    ; because it returns # of printed
+    ; because it returns the # of
-    ; characters
+    ; printed characters
     call printf, .buf
 
     blte N, rax, .dir_no_pad
@@ -160,3 +160,5 @@ N := 11
 .bytesstr = "%d kilobytes + %d bytes"
 ; .bytesstr = "%dMB + %dKB + %dB" # too soon
 
+#undef N
+

vm/ob/command.ppc

@@ -1206,7 +1206,7 @@ main:
 ; The OS/K Team licenses this file to you under the MIT license.
 ; See the LICENSE file in the project root for more information.
 
-N := 11
+
 
 .handle_DIR:
     push rbp
@@ -1263,8 +1263,8 @@ N := 11
     dec rdi
 
 .ext_pad:
-    ; print at least N non-space characters before extension
+    ; print at least 11 non-space characters before extension
-    blte N, rdi, .print_ext
+    blte 11, rdi, .print_ext
     prn ' '
     inc rdi
     jmp .ext_pad
@@ -1339,12 +1339,12 @@ N := 11
     inc r13
 
     ; use printf instead of print
-    ; because it returns # of printed
+    ; because it returns the # of
-    ; characters
+    ; printed characters
     call printf, .buf
 
-    blte N, rax, .dir_no_pad
+    blte 11, rax, .dir_no_pad
-    sub rcx, N, rax
+    sub rcx, 11, rax
     dec rcx
 
 .dir.l:

vm/ob/hello.k

@@ -0,0 +1,995 @@
+# 1 "hello.k"
+# 1 "<built-in>"
+# 1 "<command-line>"
+# 31 "<command-line>"
+# 1 "/usr/include/stdc-predef.h" 1 3 4
+# 32 "<command-line>" 2
+# 1 "hello.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.
+
+start:
+    jmp main
+
+# 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 rcx, ax1
+    scasb ax0, zero
+
+    sub rax, ax1, rcx
+    ret
+
+;
+; int strlen(char *)
+;
+strlen:
+    mov rcx, 0x7AFFFFFF
+    mov rdx, rcx
+    scasb ax0, zero
+
+    sub rax, rdx, rcx
+    ret
+
+;
+; void strcpy(char *, const char *)
+;
+strcpy:
+.l:
+    mov rcx, b[ax1]
+    mov b[ax0], rcx
+
+    jrcxz .r
+
+    inc ax0
+    inc ax1
+
+    jmp .l
+
+.r:
+    ret
+
+;
+; void strncpy(char *, const char *, int)
+;
+strncpy:
+    mov rcx, ax2
+    jrcxz .r
+
+.l:
+    mov b[ax0], b[ax1]
+
+    inc ax0
+    inc ax1
+
+    loop .l
+
+.r:
+    ret
+
+;
+; void strnzcpy(char *, const char *, int)
+;
+strnzcpy:
+    mov rcx, ax2
+    jrcxz .r
+
+.l:
+    mov rax, b[ax1]
+    mov b[ax0], rax
+
+    jraxz .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 rsi
+.l:
+    movzx rax, b[ax0+rsi]
+    movzx rdx, b[ax1+rsi]
+
+    bne rax, rdx, .r
+
+    ; both zero?
+    add rcx, rax, rdx
+    jrcxz .r
+
+    inc rsi
+    jmp .l
+
+.r:
+    sub rax, rdx
+    ret
+
+;
+; int strncmp(const char *str1, const char *str2, int maxn)
+;
+strncmp:
+    mov rcx, ax2
+    jrcxz .r
+
+.l:
+    movzx rax, b[ax0]
+    movzx rdx, b[ax1]
+
+    bne rax, rdx, .r
+
+    inc ax0
+    inc ax1
+    loop .l
+
+.r:
+    sub rax, rdx
+    ret
+
+;
+; char *strchrnul(const char *str, int ch)
+;
+strchrnul:
+    mov rcx, 0x7AFFFFFF
+    scasb ax0, ax1
+
+    mov rax, ax0
+    ret
+
+;
+; char *strchr(const char *str, int ch)
+;
+strchr:
+    mov rcx, 0x7AFFFFFF
+    scasb ax0, ax1
+
+    bnz b[ax0], .r
+    nul rax
+    ret
+
+.r:
+    mov rax, 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 rsi, ax1
+
+    ; go to str's end, just before
+    ; the null terminator
+    mov rcx, 0x7AFFFFFF
+    scasb ax1, zero
+    dec ax1
+
+.l:
+    ; copy, going backward though str
+    ; and forward through buf
+    mov b[ax0], b[ax1]
+
+    beq ax1, rsi, .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 rcx, 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 rcx, ax2
+    jrcxz .r
+
+.l:
+    sub rdx, ax2, rcx
+    mov b[ax0+rdx], b[ax1+rdx]
+    loop .l
+
+.r:
+    ret
+
+;
+; void memzero(void *, int)
+;
+memzero:
+    mov rcx, ax1
+    jrcxz .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 rax, 365
+
+    ; divisible by 4?
+    rem rcx, ax0, 4
+    jrcxnz .end
+
+    ; divisible by 100?
+    rem rcx, ax0, 100
+    jrcxnz .leap
+
+    ; divisible by 400?
+    rem rcx, ax0, 400
+    jrcxnz .end
+
+.leap:
+    inc rax
+
+.end:
+    ret
+
+;
+; TIME *GetTimeUTC(void)
+;
+GetTimeUTC:
+    ytime
+
+    mov rdi, .buf
+
+    ; seconds
+    rem rsi, rax, 60
+    mov b[rdi], rsi
+
+    ; minutes
+    div rsi, rax, 60
+    rem rsi, 60
+    mov b[rdi+1], rsi
+
+    ; hours
+    div rsi, rax, 3600
+    rem rsi, 24
+    mov b[rdi+2], rsi
+
+    ; month days
+    div rsi, rax, 3600*24
+    mov b[rdi+3], rsi
+
+    ; month
+    mov b[rdi+4], rbx
+
+    ; years
+    mov w[rdi+6], rcx
+
+    ;
+    ; ydays (TODO)
+    ;
+
+    mov rax, .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 rax, ax0
+    nul rcx
+
+    ; 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 rcx, ax1, 63 ; extract ax1 sign
+    jrcxz .conv
+
+    neg ax1 ; NEG if negative
+
+    ; main loop
+.conv:
+    bzr ax1, .fini
+
+    rem rdx, ax1, ax2 ; ax1 % base
+
+    blt 9, rdx, .nondec ; rdx > 9 ?
+
+    add rdx, '0'
+    jmp .next
+
+.nondec:
+    add rdx, 55 ; 'A' - 10
+
+.next:
+    mov b[ax0], rdx
+
+    inc ax0
+
+    div ax1, ax2
+    jmp .conv
+
+    ; add minus flag, null-terminate and reverse
+.fini:
+    jrcxz .cxz
+    mov b[ax0], '-'
+    inc ax0
+
+.cxz:
+    nul b[ax0]
+
+    call strrev2, rax
+    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)
+;
+; rax = integer extracted from str
+; rdx = pointer to first invalid byte
+;
+strtol:
+    mov ax2, 1
+    jmp strtoq
+
+;
+; int strtoul(const char *str, int base)
+;
+; rax = integer extracted from str
+; rdx = 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 rax, rsi
+    mov rdx, ax0
+
+    ; make sure base is in [2, 32]
+    beq ax1, 1, .bad
+    bltu 36, ax1, .bad
+
+    ; empty string?
+    bzr b[rdx], .done
+
+.skip_spc:
+    bne b[rdx], ' ', .no_spc
+    inc rdx
+    jmp .skip_spc
+
+.no_spc:
+    ; skip +
+    bne b[rdx], '+', .no_plus
+    inc rdx
+
+.no_plus:
+    ; unsigned?
+    bzr ax2, .unsigned
+
+    ; parse '-'
+    bne b[rdx], '-', .unsigned
+    inc rdx
+    mov rsi, 1
+
+.unsigned:
+    ; base 0
+    bzr ax1, .base_0
+
+    ; base prefix?
+    bne b[rdx], '0', .main_loop
+
+    inc rdx
+    movzx rcx, b[rdx]
+
+    ; "0x"/"0b" prefix
+    jrcxz .done ; "0"
+    beq rcx, 'x', .parsed_0x
+    beq rcx, '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 rax = 0 and *rdx = 'x'
+    bne ax1, 16, .done
+    ; else
+    inc rdx
+    jmp .main_loop
+
+.parsed_0b:
+    ; are we in base 2?
+    ; if not, leave rax = 0 and *rdx = 'b'
+    bne ax1, 2, .done
+    ; else
+    inc rdx
+    jmp .main_loop
+
+.base_0:
+    ; guess base
+
+    beq b[rdx], '0', .b0_not10
+
+    ; must be base 10
+    mov ax1, 10
+    jmp .main_loop
+
+.b0_not10:
+    inc rdx
+
+    bne b[rdx], 'x', .b0_not16
+    inc rdx
+    mov ax1, 16
+    jmp .main_loop
+
+.b0_not16:
+    bne b[rdx], 'b', .b0_not2
+    inc rdx
+    mov ax1, 2
+    jmp .main_loop
+
+.b0_not2:
+    ; take octal by default
+    mov ax1, 8
+
+.main_loop:
+    movzx rcx, b[rdx]
+    inc rdx
+
+    ; between 0 and 9?
+    bltu rcx, '0', .done
+    bltu '9', rcx, .not_digit10
+
+    ; yes
+    sub rcx, '0'
+    jmp .next
+
+.not_digit10:
+    bltu rcx, 'A', .done
+    bltu 'Z', rcx, .not_digitAZ
+
+    sub rcx, 55 ; 'A' - 10
+    jmp .next
+
+.not_digitAZ:
+    bltu rcx, 'a', .done
+    bltu 'z', rcx, .done
+
+    sub rcx, 87 ; 'a' - 10
+    jmp .next
+
+.next:
+    ; too large for base?
+    blteu ax1, rcx, .done
+
+    mul rax, ax1
+    add rax, rcx
+    jmp .main_loop
+
+.done:
+    ; negative?
+    bzr rsi, .r
+
+    ; yes
+    neg rax
+
+.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 rbp
+    mov rbp, rsp
+
+    push r12, r13, r14
+    push r15, r16, r17
+
+    mov r12, ax2 ; fmt
+    mov r14, ax3 ; va_list
+    mov r15, ax1 ; n
+    mov r17, ax0 ; putc
+    nul r16 ; return value
+
+.main_loop:
+    ; find '%' or null-terminator
+    mov rcx, 0x7AFFFFFF
+    mov r13, r12
+    scasb r13, '%'
+
+    ; everything below r13 is a regular character; print it
+.print_regular:
+    beq r12, r13, .check_modf
+
+    call .doput, b[r12]
+
+    inc r12
+    jmp .print_regular
+
+.check_modf:
+    ; did we find a '%' ?
+    ; if not, then we found fmt's null-terminator; we're done
+    bne b[r12], '%', .epilogue
+
+    ; we did find a modifier / '%'
+    mov rax, b[r12+1]
+    add r12, 2
+
+    beq rax, 's', .modf_s
+    beq rax, 'c', .modf_c
+    beq rax, 'p', .modf_p
+    beq rax, 'x', .modf_x
+    beq rax, 'd', .modf_d
+    beq rax, 'o', .modf_o
+    beq rax, 'b', .modf_b
+    beq rax, '%', .modf_percent
+
+    ; unrecognized
+    jmp .bad_modifier
+
+.modf_s:
+    ; get string address
+    mov r13, q[r14]
+    add r14, 8
+
+    bzr r13, .nullstring
+
+.print_string:
+    movzx ax0, b[r13]
+    bzr ax0, .main_loop
+
+    inc r13
+    call .doput
+
+    jmp .print_string
+
+.modf_c:
+    call .doput, q[r14]
+    add r14, 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 rsp, 80
+    mov r13, rsp
+
+    ; assume modifier already set up ax2
+    call itoa, rsp, q[r14]
+    add r14, 8
+
+.print_itoa_buf:
+    movzx ax0, b[r13]
+
+    bzr ax0, .pib_end_loop
+    inc r13
+
+    call .doput
+    jmp .print_itoa_buf
+
+.pib_end_loop:
+    add rsp, 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 rax, r16
+
+    pop r17, r16
+    pop r15, r14
+    pop r13, r12
+
+    leave
+    ret
+;
+; prints ax0
+;
+.doput:
+    ; update print count
+    inc r16
+
+    ; 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 r15, .r
+
+    ; decrement n and print
+    dec r15
+    call r17
+
+    ; did putc fail?
+    jraxz .r
+
+    ; yes, so artificially set n=0
+    nul r15
+
+.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 rax
+    ret
+
+;
+; int printf(const char *fmt, ...)
+;
+printf:
+    mov ax2, ax0
+    mov ax0, putc
+    mov ax1, 0x7AFFFFFF
+    add ax3, rsp, 8
+    jmp doprnt
+
+;
+; int nprintf(const char *fmt, int n, ...)
+;
+nprintf:
+    mov ax2, ax0
+    mov ax0, putc
+    add ax3, rsp, 8
+    jmp doprnt
+
+;
+; Print a string
+; Guaranteed to only affect rcx and ax0
+;
+print:
+.l:
+    movzx rax, b[ax0]
+    jraxz .r
+
+    prn rax
+    inc ax0
+
+    jmp .l
+
+.r:
+    ret
+
+;
+; Print exactly ax1 characters
+;
+nprint:
+    mov rcx, ax1
+    jrcxz .r
+
+.l:
+    prn b[ax0]
+    inc ax0
+    loop .l
+.r:
+    ret
+# 51 "crt/crt.k" 2
+
+exit:
+    mov rax, Sys.Exit
+    trap 0
+
+abort:
+    crash
+# 8 "hello.k" 2
+
+main:
+    mov rsp, 0x104000
+    nul rbp
+
+    call print, .hellow
+
+    jmp exit
+
+.hellow = "Hello World!\n"