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FreeDOS/kernel/main.c
Bart Oldeman f6d62165e0 ia16-elf-gcc: introduce DOSTEXT and DOSDATA macros. 
Using DOSTEXT(x) accesses x in LGROUP and DOSDATA(x) in DGROUP.
This is necessary since ia16-elf-gcc does not understand data
in far segments.

For non-macro'ed symbols, FP_SEG needs to be replaced by explicit
segment references.
2018-01-11 17:50:31 -05:00

795 lines
21 KiB
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/****************************************************************/
/* */
/* main.c */
/* DOS-C */
/* */
/* Main Kernel Functions */
/* */
/* Copyright (c) 1995, 1996 */
/* Pasquale J. Villani */
/* All Rights Reserved */
/* */
/* This file is part of DOS-C. */
/* */
/* DOS-C is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU General Public License */
/* as published by the Free Software Foundation; either version */
/* 2, or (at your option) any later version. */
/* */
/* DOS-C is distributed in the hope that it will be useful, but */
/* WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See */
/* the GNU General Public License for more details. */
/* */
/* You should have received a copy of the GNU General Public */
/* License along with DOS-C; see the file COPYING. If not, */
/* write to the Free Software Foundation, Inc., */
/* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */
/****************************************************************/
#include "portab.h"
#include "init-mod.h"
#include "dyndata.h"
#include "debug.h"
#ifdef VERSION_STRINGS
static BYTE *mainRcsId =
"$Id: main.c 1699 2012-01-16 20:45:44Z perditionc $";
#endif
static char copyright[] =
"(C) Copyright 1995-2012 Pasquale J. Villani and The FreeDOS Project.\n"
"All Rights Reserved. This is free software and comes with ABSOLUTELY NO\n"
"WARRANTY; you can redistribute it and/or modify it under the terms of the\n"
"GNU General Public License as published by the Free Software Foundation;\n"
"either version 2, or (at your option) any later version.\n";
struct _KernelConfig InitKernelConfig BSS_INIT({0});
STATIC VOID InitIO(void);
STATIC VOID update_dcb(struct dhdr FAR *);
STATIC VOID init_kernel(VOID);
STATIC VOID signon(VOID);
STATIC VOID kernel(VOID);
STATIC VOID FsConfig(VOID);
STATIC VOID InitPrinters(VOID);
STATIC VOID InitSerialPorts(VOID);
STATIC void CheckContinueBootFromHarddisk(void);
STATIC void setup_int_vectors(void);
#ifdef _MSC_VER
BYTE _acrtused = 0;
__segment DosDataSeg = 0; /* serves for all references to the DOS DATA segment
necessary for MSC+our funny linking model
*/
__segment DosTextSeg = 0;
#endif
struct lol FAR *LoL
#ifndef __GNUC__
/* cannot initialize from far data with GCC */
= &DATASTART;
#endif
;
VOID ASMCFUNC FreeDOSmain(void)
{
unsigned char drv;
unsigned char FAR *p;
#ifdef _MSC_VER
extern FAR prn_dev;
DosDataSeg = (__segment) & DATASTART;
DosTextSeg = (__segment) & prn_dev;
#endif
/* clear the Init BSS area (what normally the RTL does */
memset(_ib_start, 0, _ib_end - _ib_start);
/* if the kernel has been UPX'ed,
CONFIG info is stored at 50:e2 ..fc
and the bootdrive (passed from BIOS)
at 50:e0
*/
#ifdef __GNUC__
LoL = &DATASTART;
#endif
drv = LoL->BootDrive + 1;
p = MK_FP(0, 0x5e0);
if (fmemcmp(p+2,"CONFIG",6) == 0) /* UPX */
{
fmemcpy(&InitKernelConfig, p+2, sizeof(InitKernelConfig));
drv = *p + 1;
*(DWORD FAR *)(p+2) = 0;
}
else
{
*p = drv - 1;
fmemcpy(&InitKernelConfig, &LowKernelConfig, sizeof(InitKernelConfig));
}
if (drv >= 0x80)
drv = 3; /* C: */
LoL->BootDrive = drv;
/* install DOS API and other interrupt service routines, basic kernel functionality works */
setup_int_vectors();
CheckContinueBootFromHarddisk();
/* display copyright info and kernel emulation status */
signon();
/* initialize all internal variables, process CONFIG.SYS, load drivers, etc */
init_kernel();
#ifdef DEBUG
/* Non-portable message kludge alert! */
printf("KERNEL: Boot drive = %c\n", 'A' + LoL->BootDrive - 1);
#endif
DoInstall();
kernel();
}
/*
InitializeAllBPBs()
or MakeNortonDiskEditorHappy()
it has been determined, that FDOS's BPB tables are initialized,
only when used (like DIR H:).
at least one known utility (norton DE) seems to access them directly.
ok, so we access for all drives, that the stuff gets build
*/
void InitializeAllBPBs(VOID)
{
static char filename[] = "A:-@JUNK@-.TMP";
int drive, fileno;
for (drive = 'C'; drive < 'A' + LoL->nblkdev; drive++)
{
filename[0] = drive;
if ((fileno = open(filename, O_RDONLY)) >= 0)
close(fileno);
}
}
STATIC void PSPInit(void)
{
psp far *p = MK_FP(DOS_PSP, 0);
/* Clear out new psp first */
fmemset(p, 0, sizeof(psp));
/* initialize all entries and exits */
/* CP/M-like exit point */
p->ps_exit = 0x20cd;
/* CP/M-like entry point - call far to special entry */
p->ps_farcall = 0x9a;
p->ps_reentry = MK_FP(0, 0x30 * 4);
/* unix style call - 0xcd 0x21 0xcb (int 21, retf) */
p->ps_unix[0] = 0xcd;
p->ps_unix[1] = 0x21;
p->ps_unix[2] = 0xcb;
/* Now for parent-child relationships */
/* parent psp segment */
p->ps_parent = FP_SEG(p);
/* previous psp pointer */
p->ps_prevpsp = MK_FP(0xffff,0xffff);
/* Environment and memory useage parameters */
/* memory size in paragraphs */
/* p->ps_size = 0; clear from above */
/* environment paragraph */
p->ps_environ = DOS_PSP + 8;
/* terminate address */
p->ps_isv22 = getvec(0x22);
/* break address */
p->ps_isv23 = getvec(0x23);
/* critical error address */
p->ps_isv24 = getvec(0x24);
/* user stack pointer - int 21 */
/* p->ps_stack = NULL; clear from above */
/* File System parameters */
/* maximum open files */
p->ps_maxfiles = 20;
fmemset(p->ps_files, 0xff, 20);
/* open file table pointer */
p->ps_filetab = p->ps_files;
/* first command line argument */
/* p->ps_fcb1.fcb_drive = 0; already set */
fmemset(p->ps_fcb1.fcb_fname, ' ', FNAME_SIZE + FEXT_SIZE);
/* second command line argument */
/* p->ps_fcb2.fcb_drive = 0; already set */
fmemset(p->ps_fcb2.fcb_fname, ' ', FNAME_SIZE + FEXT_SIZE);
/* local command line */
/* p->ps_cmd.ctCount = 0; command tail, already set */
p->ps_cmd.ctBuffer[0] = 0xd; /* command tail */
}
#ifndef __WATCOMC__
/* for WATCOMC we can use the ones in task.c */
intvec getvec(unsigned char intno)
{
intvec iv;
disable();
iv = *(intvec FAR *)MK_FP(0,4 * (intno));
enable();
return iv;
}
void setvec(unsigned char intno, intvec vector)
{
disable();
*(intvec FAR *)MK_FP(0,4 * intno) = vector;
enable();
}
#endif
STATIC void setup_int_vectors(void)
{
static struct vec
{
unsigned char intno;
size_t handleroff;
} vectors[] =
{
/* all of these are in the DOS DS */
{ 0x0, FP_OFF(int0_handler) }, /* zero divide */
{ 0x1, FP_OFF(empty_handler) }, /* single step */
{ 0x3, FP_OFF(empty_handler) }, /* debug breakpoint */
{ 0x6, FP_OFF(int6_handler) }, /* invalid opcode */
{ 0x19, FP_OFF(int19_handler) },
{ 0x20, FP_OFF(int20_handler) },
{ 0x21, FP_OFF(int21_handler) },
{ 0x22, FP_OFF(int22_handler) },
{ 0x24, FP_OFF(int24_handler) },
{ 0x25, FP_OFF(low_int25_handler) },
{ 0x26, FP_OFF(low_int26_handler) },
{ 0x27, FP_OFF(int27_handler) },
{ 0x28, FP_OFF(int28_handler) },
{ 0x2a, FP_OFF(int2a_handler) },
{ 0x2f, FP_OFF(int2f_handler) }
};
struct vec *pvec;
struct lowvec FAR *plvec;
int i;
for (plvec = intvec_table; plvec < intvec_table + 5; plvec++)
plvec->isv = getvec(plvec->intno);
for (i = 0x23; i <= 0x3f; i++)
setvec(i, DOSDATA(empty_handler));
HaltCpuWhileIdle = 0;
for (pvec = vectors; pvec < vectors + (sizeof vectors/sizeof *pvec); pvec++)
setvec(pvec->intno, (intvec)MK_FP(FP_SEG(DOSDATA(empty_handler)), pvec->handleroff));
pokeb(0, 0x30 * 4, 0xea);
pokel(0, 0x30 * 4 + 1, (ULONG)cpm_entry);
/* these two are in the device driver area LOWTEXT (0x70) */
setvec(0x1b, got_cbreak);
setvec(0x29, int29_handler); /* required for printf! */
}
STATIC void init_kernel(void)
{
COUNT i;
LoL->os_setver_major = LoL->os_major = MAJOR_RELEASE;
LoL->os_setver_minor = LoL->os_minor = MINOR_RELEASE;
/* Init oem hook - returns memory size in KB */
ram_top = init_oem();
/* move kernel to high conventional RAM, just below the init code */
#ifdef __WATCOMC__
lpTop = MK_FP(_CS, 0);
#else
lpTop = MK_FP(_CS - (FP_OFF(_HMATextEnd) + 15) / 16, 0);
#endif
MoveKernel(FP_SEG(lpTop));
lpTop = MK_FP(FP_SEG(lpTop) - 0xfff, 0xfff0);
/* Initialize IO subsystem */
InitIO();
InitPrinters();
InitSerialPorts();
init_PSPSet(DOS_PSP);
set_DTA(MK_FP(DOS_PSP, 0x80));
PSPInit();
Init_clk_driver();
/* Do first initialization of system variable buffers so that */
/* we can read config.sys later. */
/* use largest possible value for the initial CDS */
LoL->lastdrive = 26;
/* init_device((struct dhdr FAR *)&blk_dev, NULL, 0, &ram_top); */
blk_dev.dh_name[0] = dsk_init();
PreConfig();
/* Number of units */
if (blk_dev.dh_name[0] > 0)
update_dcb(&blk_dev);
/* Now config the temporary file system */
FsConfig();
/* Now process CONFIG.SYS */
DoConfig(0);
DoConfig(1);
/* initialize near data and MCBs */
PreConfig2();
/* and process CONFIG.SYS one last time for device drivers */
DoConfig(2);
/* Close all (device) files */
for (i = 0; i < 20; i++)
close(i);
/* and do final buffer allocation. */
PostConfig();
/* Init the file system one more time */
FsConfig();
configDone();
InitializeAllBPBs();
}
STATIC VOID FsConfig(VOID)
{
struct dpb FAR *dpb = LoL->DPBp;
int i;
/* Initialize the current directory structures */
for (i = 0; i < LoL->lastdrive; i++)
{
struct cds FAR *pcds_table = &LoL->CDSp[i];
fmemcpy(pcds_table->cdsCurrentPath, "A:\\\0", 4);
pcds_table->cdsCurrentPath[0] += i;
if (i < LoL->nblkdev && (ULONG) dpb != 0xffffffffl)
{
pcds_table->cdsDpb = dpb;
pcds_table->cdsFlags = CDSPHYSDRV;
dpb = dpb->dpb_next;
}
else
{
pcds_table->cdsFlags = 0;
}
pcds_table->cdsStrtClst = 0xffff;
pcds_table->cdsParam = 0xffff;
pcds_table->cdsStoreUData = 0xffff;
pcds_table->cdsJoinOffset = 2;
}
/* Log-in the default drive. */
init_setdrive(LoL->BootDrive - 1);
/* The system file tables need special handling and are "hand */
/* built. Included is the stdin, stdout, stdaux and stdprn. */
/* a little bit of shuffling is necessary for compatibility */
/* sft_idx=0 is /dev/aux */
open("AUX", O_RDWR);
/* handle 1, sft_idx=1 is /dev/con (stdout) */
open("CON", O_RDWR);
/* 3 is /dev/aux */
dup2(STDIN, STDAUX);
/* 0 is /dev/con (stdin) */
dup2(STDOUT, STDIN);
/* 2 is /dev/con (stdin) */
dup2(STDOUT, STDERR);
/* 4 is /dev/prn */
open("PRN", O_WRONLY);
/* Initialize the disk buffer management functions */
/* init_call_init_buffers(); done from CONFIG.C */
}
STATIC VOID signon()
{
printf("\r%S"
"Kernel compatibility %d.%d - "
#if defined(__BORLANDC__)
"BORLANDC"
#elif defined(__TURBOC__)
"TURBOC"
#elif defined(_MSC_VER)
"MSC"
#elif defined(__WATCOMC__)
"WATCOMC"
#elif defined(__GNUC__)
"GNUC" /* this is hypothetical only */
#else
#error Unknown compiler
generate some bullshit error here, as the compiler should be known
#endif
#if defined (I386)
" - 80386 CPU required"
#elif defined (I186)
" - 80186 CPU required"
#endif
#ifdef WITHFAT32
" - FAT32 support"
#endif
"\n\n%s",
MK_FP(FP_SEG(LoL), FP_OFF(LoL->os_release)),
MAJOR_RELEASE, MINOR_RELEASE, copyright);
}
STATIC void kernel()
{
CommandTail Cmd;
if (master_env[0] == '\0') /* some shells panic on empty master env. */
strcpy(master_env, "PATH=.");
fmemcpy(MK_FP(DOS_PSP + 8, 0), master_env, sizeof(master_env));
/* process 0 */
/* Execute command.com from the drive we just booted from */
memset(Cmd.ctBuffer, 0, sizeof(Cmd.ctBuffer));
strcpy(Cmd.ctBuffer, Config.cfgInitTail);
for (Cmd.ctCount = 0; Cmd.ctCount < sizeof(Cmd.ctBuffer); Cmd.ctCount++)
if (Cmd.ctBuffer[Cmd.ctCount] == '\r')
break;
/* if stepping CONFIG.SYS (F5/F8), tell COMMAND.COM about it */
/* 3 for string + 2 for "\r\n" */
if (Cmd.ctCount < sizeof(Cmd.ctBuffer) - 5)
{
char *insertString = NULL;
if (singleStep)
insertString = " /Y"; /* single step AUTOEXEC */
if (SkipAllConfig)
insertString = " /D"; /* disable AUTOEXEC */
if (insertString)
{
/* insert /D, /Y as first argument */
char *p, *q;
for (p = Cmd.ctBuffer; p < &Cmd.ctBuffer[Cmd.ctCount]; p++)
{
if (*p == ' ' || *p == '\t' || *p == '\r')
{
for (q = &Cmd.ctBuffer[Cmd.ctCount + 1]; q >= p; q--)
q[3] = q[0];
memcpy(p, insertString, 3);
break;
}
}
/* save buffer -- on the stack it's fine here */
Config.cfgInitTail = Cmd.ctBuffer;
}
}
init_call_p_0(&Config); /* go execute process 0 (the shell) */
}
/* check for a block device and update device control block */
STATIC VOID update_dcb(struct dhdr FAR * dhp)
{
REG COUNT Index;
COUNT nunits = dhp->dh_name[0];
struct dpb FAR *dpb;
if (LoL->nblkdev == 0)
dpb = LoL->DPBp;
else
{
for (dpb = LoL->DPBp; (ULONG) dpb->dpb_next != 0xffffffffl;
dpb = dpb->dpb_next)
;
dpb = dpb->dpb_next =
KernelAlloc(nunits * sizeof(struct dpb), 'E', Config.cfgDosDataUmb);
}
for (Index = 0; Index < nunits; Index++)
{
dpb->dpb_next = dpb + 1;
dpb->dpb_unit = LoL->nblkdev;
dpb->dpb_subunit = Index;
dpb->dpb_device = dhp;
dpb->dpb_flags = M_CHANGED;
if ((LoL->CDSp != 0) && (LoL->nblkdev < LoL->lastdrive))
{
LoL->CDSp[LoL->nblkdev].cdsDpb = dpb;
LoL->CDSp[LoL->nblkdev].cdsFlags = CDSPHYSDRV;
}
++dpb;
++LoL->nblkdev;
}
(dpb - 1)->dpb_next = (void FAR *)0xFFFFFFFFl;
}
/* If cmdLine is NULL, this is an internal driver */
BOOL init_device(struct dhdr FAR * dhp, char *cmdLine, COUNT mode,
char FAR **r_top)
{
request rq;
char name[8];
if (cmdLine) {
char *p, *q, ch;
int i;
p = q = cmdLine;
for (;;)
{
ch = *p;
if (ch == '\0' || ch == ' ' || ch == '\t')
break;
p++;
if (ch == '\\' || ch == '/' || ch == ':')
q = p; /* remember position after path */
}
for (i = 0; i < 8; i++) {
ch = '\0';
if (p != q && *q != '.')
ch = *q++;
/* copy name, without extension */
name[i] = ch;
}
}
rq.r_unit = 0;
rq.r_status = 0;
rq.r_command = C_INIT;
rq.r_length = sizeof(request);
rq.r_endaddr = *r_top;
rq.r_bpbptr = (void FAR *)(cmdLine ? cmdLine : "\n");
rq.r_firstunit = LoL->nblkdev;
execrh((request FAR *) & rq, dhp);
/*
* Added needed Error handle
*/
if ((rq.r_status & (S_ERROR | S_DONE)) == S_ERROR)
return TRUE;
if (cmdLine)
{
/* Don't link in device drivers which do not take up memory */
if (rq.r_endaddr == (BYTE FAR *) dhp)
return TRUE;
/* Don't link in block device drivers which indicate no units */
if (!(dhp->dh_attr & ATTR_CHAR) && !rq.r_nunits)
{
rq.r_endaddr = (BYTE FAR *) dhp;
return TRUE;
}
/* Fix for multisegmented device drivers: */
/* If there are multiple device drivers in a single driver file, */
/* only the END ADDRESS returned by the last INIT call should be */
/* the used. It is recommended that all the device drivers in */
/* the file return the same address */
if (FP_OFF(dhp->dh_next) == 0xffff)
{
KernelAllocPara(FP_SEG(rq.r_endaddr) + (FP_OFF(rq.r_endaddr) + 15)/16
- FP_SEG(dhp), 'D', name, mode);
}
/* Another fix for multisegmented device drivers: */
/* To help emulate the functionallity experienced with other DOS */
/* operating systems when calling multiple device drivers in a */
/* single driver file, save the end address returned from the */
/* last INIT call which will then be passed as the end address */
/* for the next INIT call. */
*r_top = (char FAR *)rq.r_endaddr;
}
if (!(dhp->dh_attr & ATTR_CHAR) && (rq.r_nunits != 0))
{
dhp->dh_name[0] = rq.r_nunits;
update_dcb(dhp);
}
if (dhp->dh_attr & ATTR_CONIN)
LoL->syscon = dhp;
else if (dhp->dh_attr & ATTR_CLOCK)
LoL->clock = dhp;
return FALSE;
}
STATIC void InitIO(void)
{
struct dhdr far *device = &LoL->nul_dev;
/* Initialize driver chain */
do {
init_device(device, NULL, 0, &lpTop);
device = device->dh_next;
}
while (FP_OFF(device) != 0xffff);
}
/* issue an internal error message */
VOID init_fatal(BYTE * err_msg)
{
printf("\nInternal kernel error - %s\nSystem halted\n", err_msg);
for (;;) ;
}
/*
Initialize all printers
this should work. IMHO, this might also be done on first use
of printer, as I never liked the noise by a resetting printer, and
I usually much more often reset my system, then I print :-)
*/
STATIC VOID InitPrinters(VOID)
{
iregs r;
int num_printers, i;
init_call_intr(0x11, &r); /* get equipment list */
num_printers = (r.a.x >> 14) & 3; /* bits 15-14 */
for (i = 0; i < num_printers; i++)
{
r.a.x = 0x0100; /* initialize printer */
r.d.x = i;
init_call_intr(0x17, &r);
}
}
STATIC VOID InitSerialPorts(VOID)
{
iregs r;
int serial_ports, i;
init_call_intr(0x11, &r); /* get equipment list */
serial_ports = (r.a.x >> 9) & 7; /* bits 11-9 */
for (i = 0; i < serial_ports; i++)
{
r.a.x = 0xA3; /* initialize serial port to 2400,n,8,1 */
r.d.x = i;
init_call_intr(0x14, &r);
}
}
/*****************************************************************
if kernel.config.BootHarddiskSeconds is set,
the default is to boot from harddisk, because
the user is assumed to just have forgotten to
remove the floppy/bootable CD from the drive.
user has some seconds to hit ANY key to continue
to boot from floppy/cd, else the system is
booted from HD
*/
STATIC int EmulatedDriveStatus(int drive,char statusOnly)
{
iregs r;
char buffer[0x13];
buffer[0] = 0x13;
r.a.b.h = 0x4b; /* bootable CDROM - get status */
r.a.b.l = statusOnly;
r.d.b.l = (char)drive;
r.si = (int)buffer;
init_call_intr(0x13, &r);
if (r.flags & 1)
return FALSE;
return TRUE;
}
STATIC void CheckContinueBootFromHarddisk(void)
{
char *bootedFrom = "Floppy/CD";
iregs r;
int key;
if (InitKernelConfig.BootHarddiskSeconds == 0)
return;
if (LoL->BootDrive >= 3)
{
#if 0
if (!EmulatedDriveStatus(0x80,1))
#endif
{
/* already booted from HD */
return;
}
}
else {
#if 0
if (!EmulatedDriveStatus(0x00,1))
#endif
bootedFrom = "Floppy";
}
printf("\n"
"\n"
"\n"
" Hit any key within %d seconds to continue boot from %s\n"
" Hit 'H' or wait %d seconds to boot from Harddisk\n",
InitKernelConfig.BootHarddiskSeconds,
bootedFrom,
InitKernelConfig.BootHarddiskSeconds
);
key = GetBiosKey(InitKernelConfig.BootHarddiskSeconds);
if (key != -1 && (key & 0xff) != 'h' && (key & 0xff) != 'H')
{
/* user has hit a key, continue to boot from floppy/CD */
printf("\n");
return;
}
/* reboot from harddisk */
EmulatedDriveStatus(0x00,0);
EmulatedDriveStatus(0x80,0);
/* now jump and run */
r.a.x = 0x0201;
r.c.x = 0x0001;
r.d.x = 0x0080;
r.b.x = 0x7c00;
r.es = 0;
init_call_intr(0x13, &r);
{
#if __GNUC__
asm volatile("jmp $0,$0x7c00");
#else
void (far *reboot)(void) = (void (far*)(void)) MK_FP(0x0,0x7c00);
(*reboot)();
#endif
}
}
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