ia16-elf-gcc: provide GNU LD linker script and symbols to link kernel.

The resulting kernel and sys.com do not work yet (kernel prints 123 only).
Some functions in sys.com are placeholders.

hdr/portab.h

@@ -143,6 +143,15 @@ unsigned short getSS(void);
 
 #ifdef __FAR
 #define I86
+#define __int__(intno) asm volatile("int " ## #intno)
+static inline void disable(void)
+{
+  asm volatile("cli");
+}
+static inline void enable(void)
+{
+  asm volatile("sti");
+}
 #define far __far
 #define CDECL
 #define VA_CDECL

kernel/globals.h

@@ -160,7 +160,14 @@ extern struct dhdr FAR ASM clk_dev; /* Clock device driver                  */
 extern struct dhdr FAR ASM con_dev; /* Console device driver                */
 extern struct dhdr FAR ASM prn_dev; /* Generic printer device driver        */
 extern struct dhdr FAR ASM aux_dev; /* Generic aux device driver            */
+#ifndef __GNUC__
 extern struct dhdr FAR ASM blk_dev; /* Block device (Disk) driver           */
+#else
+extern struct dhdr ASM blk_dev;
+#define DosTextSeg 0x70
+#define DOSTEXT(x) (*(typeof(x) FAR *)MK_FP(DosTextSeg, (size_t)&(x)))
+#define blk_dev DOSTEXT(blk_dev)
+#endif
 extern COUNT *error_tos,        /* error stack                          */
   disk_api_tos,                 /* API handler stack - disk fns         */
   char_api_tos;                 /* API handler stack - char fns         */

kernel/inithma.c

@@ -78,7 +78,7 @@ UWORD HMAFree BSS_INIT(0);            /* first byte in HMA not yet used      */
 STATIC void InstallVDISK(void);
 
 #ifdef DEBUG
-#ifdef __TURBOC__
+#if defined(__TURBOC__) || defined(__GNUC__)
 #define int3() __int__(3);
 #else
 void int3()

kernel/kernel.asm

@@ -887,6 +887,26 @@ __U4D:
                 LDIVMODU
 %endif
 
+%ifdef gcc
+global ___udivsi3
+___udivsi3:     call ldivmodu
+                ret 8
+
+global ___umodsi3
+___umodsi3:     call ldivmodu
+                mov dx, cx
+                mov ax, bx
+                ret 8
+
+ldivmodu:       LDIVMODU
+
+global ___ashlsi3
+___ashlsi3:     LSHLU
+
+global ___lshrsi3
+___lshrsi3:     LSHRU
+%endif
+
                 times 0xd0 - ($-begin_hma) db 0
                 ; reserve space for far jump to cp/m routine
                 times 5 db 0

kernel/kernel.ld

@@ -0,0 +1,186 @@
+/* Linker script for DOS executables with separate data and text segments.
+   Partly derived from dos-exe-small.ld in newlib-ia16 and elks-separate.ld. */
+
+OUTPUT_FORMAT(binary)
+
+DOS_PSP = 0x60;
+MEMOFS = DOS_PSP * 16 - SIZEOF(.hdr);
+
+/* these GROUPs play the same role as GROUPS (segments) in OMF */
+PGROUP = (MEMOFS + LOADADDR(.ptext)) / 16;
+LGROUP = (MEMOFS + LOADADDR(.ltext)) / 16;
+DGROUP = (MEMOFS + LOADADDR(.data)) / 16;
+_DosDataSeg = DGROUP;
+TGROUP = (MEMOFS + LOADADDR(.text)) / 16;
+IGROUP = (MEMOFS + LOADADDR(.itext)) / 16;
+I_GROUP = (MEMOFS + LOADADDR(.idata)) / 16;
+
+INITSIZE = SIZEOF(.itext) + SIZEOF(.idata) + SIZEOF(.ibss);
+
+SECTIONS
+  {
+    /* Fabricate a .exe header here.  Although libbfd does have an
+       "i386msdos" back-end which produces an "MZ" exe header, it cannot do
+       certain things (yet). */
+    .hdr : {
+		/* Signature.  */
+		SHORT (0x5a4d)
+		/* Bytes in last 512-byte page.  */
+		SHORT (LOADADDR (.ibss) % 512)
+		/* Total number of 512-byte pages.  */
+		SHORT (ALIGN(LOADADDR (.ibss), 512) / 512)
+		/* Relocation entries.  */
+		SHORT (0)
+		/* Header size in paragraphs.  */
+		SHORT (SIZEOF(.hdr) / 16)
+		/* Minimum extra paragraphs.  */
+		SHORT (ALIGN(SIZEOF (.ibss) + SIZEOF(.istack), 16) / 16)
+		/* Maximum extra paragraphs.  */
+		SHORT (0xffff)
+		/* Initial %ss.  */
+		SHORT (LOADADDR (.istack) / 16 )
+		/* Initial %sp. */
+		SHORT (LOADADDR (.istack) % 16 + SIZEOF(.istack))
+		/* Padding for Checksum (unused) and initial cs:ip (0:0) */
+		. = 0x18;
+		/* Relocation table offset.  */
+		SHORT (. + 4)
+		/* Overlay number + padding */
+                . = ALIGN (32);
+    }
+
+    /* Target PSP section.  */
+    .ptext 0 : AT (SIZEOF(.hdr)) {
+		*(PSP)
+    }
+
+    /* Target low data+text sections.  */
+    .ltext 0 : AT (LOADADDR(.ptext) + SIZEOF(.ptext)) {
+		*(_IRQTEXT)
+		*(_LOWTEXT)
+		*(_IO_TEXT)
+		*(_IO_FIXED_DATA)
+    }
+
+    /* Target data sections.  */
+    .data 0 : AT (ALIGN(LOADADDR(.ltext) + SIZEOF(.ltext), 16)) {
+		*(_FIXED_DATA)
+		*(_BSS)
+		*(EXCLUDE_FILE (config.obj iasmsupt.obj *init*.obj iprf.obj main.obj) .bss)
+		*(_DATA)
+		*(EXCLUDE_FILE (config.obj iasmsupt.obj *init*.obj iprf.obj main.obj) .data)
+		*(_DATAEND)
+		*(CONST)
+		*(CONST2)
+		*(EXCLUDE_FILE (config.obj iasmsupt.obj *init*.obj iprf.obj main.obj) .rodata)
+		*(EXCLUDE_FILE (config.obj iasmsupt.obj *init*.obj iprf.obj main.obj) .rodata.*)
+		*(DYN_DATA)
+		ASSERT(. <= 0xfff8,
+		    "Error: too large for a small-model .exe file.");
+	}
+
+    /* Target text sections.  */
+    .text 0 : AT (ALIGN(LOADADDR(.data) + SIZEOF(.data), 16)) {
+		*(HMA_TEXT_START)
+		*(HMA_TEXT)
+		_res_DosExec = RES_DOSEXEC;
+		_res_read = RES_READ;
+		_strlen = STRLEN;
+		_fstrlen = FSTRLEN;
+		_strlen = STRLEN;
+		_fstrcmp = FSTRCMP;
+		_strchr = STRCHR;
+		_fstrchr = FSTRCHR;
+		_fmemchr = FMEMCHR;
+		_strcpy = STRCPY;
+		_fmemcpy = FMEMCPY;
+		_fstrcpy = FSTRCPY;
+		_memcpy = MEMCPY;
+		_fmemset = FMEMSET;
+		_memset = MEMSET;
+		_memcmp = MEMCMP;
+		_fmemcmp = FMEMCMP;
+		_network_redirector_mx = NETWORK_REDIRECTOR_MX;
+		_execrh = EXECRH;
+		_share_check = SHARE_CHECK;
+		_share_open_check = SHARE_OPEN_CHECK;
+		_share_close_file = SHARE_CLOSE_FILE;
+		_share_access_check = SHARE_ACCESS_CHECK;
+		_share_lock_unlock = SHARE_LOCK_UNLOCK;
+		_call_nls = CALL_NLS;
+		_fl_reset = FL_RESET;
+		_fl_diskchanged = FL_DISKCHANGED;
+		_fl_format = FL_FORMAT;
+		_fl_read = FL_READ;
+		_fl_write = FL_WRITE;
+		_fl_verify = FL_VERIFY;
+		_fl_setdisktype = FL_SETDISKTYPE;
+		_fl_setmediatype = FL_SETMEDIATYPE;
+		_fl_readkey = FL_READKEY;
+		_fl_lba_ReadWrite = FL_LBA_READWRITE;
+		_floppy_change = FLOPPY_CHANGE;
+		_ReadPCClock = READPCCLOCK;
+		_WritePCClock = WRITEPCCLOCK;
+		_WriteATClock = WRITEATCLOCK;
+		*(EXCLUDE_FILE (config.obj iasmsupt.obj *init*.obj iprf.obj main.obj) .text)
+		*(HMA_TEXT_END)
+		ASSERT(. <= 0x10000,
+		    "Error: too large for a small-model .exe file.");
+	}
+
+    /* Target init text sections. */
+    .itext 0 : AT (LOADADDR(.text) + SIZEOF(.text)) {
+		*(INIT_TEXT_START)
+		*(INIT_TEXT)
+                _init_execrh = INIT_EXECRH;
+                _init_memset = INIT_MEMSET;
+                _init_fmemset = INIT_FMEMSET;
+                _init_memcmp = INIT_MEMCMP;
+                _init_fmemcmp = INIT_FMEMCMP;
+                _init_memcpy = INIT_MEMCPY;
+                _init_fmemcpy = INIT_FMEMCPY;
+                _init_strcpy = INIT_STRCPY;
+                _init_strlen = INIT_STRLEN;
+                _init_strchr = INIT_STRCHR;
+                _UMB_get_largest = UMB_GET_LARGEST;
+		_init_call_intr = INIT_CALL_INTR;
+		_read = READ;
+		_init_DosOpen = INIT_DOSOPEN;
+		_close = CLOSE;
+		_dup2 = DUP2;
+		_lseek = LSEEK;
+		_allocmem = ALLOCMEM;
+		_init_PSPSet = INIT_PSPSET;
+		_init_DosExec = INIT_DOSEXEC;
+		_init_setdrive = INIT_SETDRIVE;
+		_init_switchar = INIT_SWITCHAR;
+		_keycheck = KEYCHECK;
+		_set_DTA = SET_DTA;
+		_DetectXMSDriver = DETECTXMSDRIVER;
+		_init_call_XMScall = INIT_CALL_XMSCALL;
+		__EnableA20 = _ENABLEA20;
+		__DisableA20 = _DISABLEA20;
+		*(.text)
+		*(INIT_TEXT_END)
+		ASSERT(. <= 0x10000,
+		    "Error: too large for a small-model .exe file.");
+	}
+
+    /* Target init data sections.  */
+    .idata 0 : AT (LOADADDR(.itext) + SIZEOF(.itext)) {
+		*(ID_B)
+		*(.data)
+		*(.rodata) *(.rodata.*)
+		*(ID_E)
+	}
+    .ibss (NOLOAD) : AT (LOADADDR(.idata) + SIZEOF(.idata)) {
+		*(IB_B)
+		*(.bss)
+		*(IB_E)
+	}
+    .istack 0 (NOLOAD) : AT (LOADADDR(.ibss) + SIZEOF(.ibss)) {
+		*(_STACK)
+		. = 0x1000;
+	}
+    /DISCARD/ : { *(.*) }
+  }

kernel/ludivmul.inc

@@ -110,3 +110,29 @@
 	ret
 
 %endmacro
+
+%macro LSHLU 0
+	pop bx
+	pop ax
+	pop dx
+	pop cx
+	push bx
+	jcxz %%ret
+%%loop: shl ax, 1
+	rcl dx, 1
+	loop %%loop
+%%ret:	ret 6
+%endmacro
+
+%macro LSHRU 0
+	pop bx
+	pop ax
+	pop dx
+	pop cx
+	push bx
+	jcxz %%ret
+%%loop: shr dx, 1
+	rcr ax, 1
+	loop %%loop
+%%ret:	ret 6
+%endmacro

kernel/makefile

@@ -158,7 +158,7 @@ initclk.obj: initclk.c  $(INITHEADERS) $(TARGET).lnk
 
 #the string functions for INIT_TEXT
 iasmsupt.obj: asmsupt.asm $(TARGET).lnk
-	$(NASM) -D$(COMPILER) -D_INIT $(NASMFLAGS) -f obj -o iasmsupt.obj asmsupt.asm
+	$(NASM) -D$(COMPILER) -D_INIT -f obj $(NASMFLAGS) -o iasmsupt.obj asmsupt.asm
 
 #the printf for INIT_TEXT - yet another special case, this file includes prf.c
 iprf.obj: iprf.c prf.c $(HDR)portab.h $(TARGET).lnk

mkfiles/gcc.mak

@@ -3,7 +3,7 @@
 #
 
 CC=ia16-elf-gcc -c
-CL=echo ia16-elf-gcc
+CL=ia16-elf-gcc
 INCLUDEPATH=.
 
 !if $(XCPU) != 186
@@ -26,6 +26,7 @@ TARGET=KGC
 # heavy stuff - building  
 #
 # -mcmodel=small small memory model (small code/small data)
+# -Os           -> favor code size over execution time in optimizations
 # -fleading-underscore underscores leading field for DOS compiler compat
 # -fno-common    no "common" variables, just BSS for uninitialized data
 # -fpack-struct pack structure members
@@ -35,17 +36,17 @@ TARGET=KGC
 # -w            disable warnings for now
 # -Werror       treat all warnings as errors
 
-ALLCFLAGS=-I../hdr $(TARGETOPT) $(ALLCFLAGS) -mcmodel=small -fleading-underscore -fno-common -fpack-struct -ffreestanding -fcall-used-es -mrtd -w -Werror
+ALLCFLAGS=-I../hdr $(TARGETOPT) $(ALLCFLAGS) -mcmodel=small -fleading-underscore -fno-common -fpack-struct -ffreestanding -fcall-used-es -mrtd -w -Werror -Os
 INITCFLAGS=$(ALLCFLAGS) -o $@
 CFLAGS=$(ALLCFLAGS) -o $@
 NASMFLAGS=$(NASMFLAGS) -f elf -o $@
 
 DIRSEP=/
 RM=rm -f
-CP=echo cp
+CP=cp
 ECHOTO=echo>>
 INITPATCH=@echo > /dev/null
 CLDEF=1
 CLT=gcc -DDOSC_TIME_H -I../hdr -o $@
 CLC=$(CLT)
-XLINK=echo $(XLINK) debug all op symfile format dos option map,statics,verbose F { $(OBJS) } L ../lib/device.lib N kernel.exe $#
+XLINK=$(CL) -Tkernel.ld -Wl,-Map,kernel.map -o kernel.exe $(OBJS) -Wl,--whole-archive ../drivers/device.lib -Wl,--no-whole-archive $#

sys/sys.c

@@ -117,6 +117,52 @@ struct SREGS {
 struct _diskfree_t {
   unsigned short avail_clusters, sectors_per_cluster, bytes_per_sector;
 };
+
+int int86(int ivec, union REGS *in, union REGS *out)
+{
+}
+
+int intdos(union REGS *in, union REGS *out)
+{
+}
+
+int intdosx(union REGS *in, union REGS *out, struct SREGS *s)
+{
+}
+
+unsigned _dos_allocmem(unsigned size, unsigned *seg)
+{
+}
+
+unsigned _dos_freemem(unsigned seg)
+{
+}
+
+unsigned int _dos_getdiskfree(unsigned int drive,
+                              struct diskfree_t *diskspace)
+{
+}
+
+long filelength(int fhandle)
+{
+}
+
+struct find_t {
+  char reserved[21];
+  unsigned char attrib;
+  unsigned short wr_time;
+  unsigned short wr_date;
+  unsigned long size;
+  char filename[13];
+};
+#define _A_NORMAL 0x00
+#define _A_HIDDEN 0x02
+#define _A_SYSTEM 0x04
+
+int _dos_findfirst(const char *file_name, unsigned int attr,
+                   struct find_t *find_tbuf)
+{
+}
 #else
 #include <io.h>
 #endif
@@ -194,7 +240,9 @@ int write(int fd, const void *buf, unsigned count)
 }
 
 #define close _dos_close
+#endif
 
+#if defined(__WATCOMC__) || defined(__GNUC__)
 int stat(const char *file_name, struct stat *statbuf)
 {
   struct find_t find_tbuf;
@@ -204,7 +252,9 @@ int stat(const char *file_name, struct stat *statbuf)
   /* statbuf->st_attr = (ULONG)find_tbuf.attrib; */
   return ret;
 }
+#endif
 
+#ifdef __WATCOMC__
 /* WATCOM's getenv is case-insensitive which wastes a lot of space
    for our purposes. So here's a simple case-sensitive one */
 char *getenv(const char *name)

sys/talloc.c

@@ -33,6 +33,12 @@ extern unsigned __brklvl;
 
 #ifdef __GNUC__
 #include <unistd.h>
+static inline int brk(void *addr)
+{
+  char *brklvl = sbrk(0);
+  int *res = sbrk((char *)addr - brklvl);
+  return (res == (void *)-1) ? -1 : 0;
+}
 #endif
 
 #define BUSY	    (sizeof(size_t)-1)	/* Bit set if memory block in use*/