16-bit support!

This gets us everything we need (I hope!) to support 16-bit code in LX binaries and call into 16-bit OS/2 APIs. This is just enough to call into VioGetMode() (which isn't otherwise implemented yet) as an example. If this is ever used Winelib-style to provide an OS/2 API to native Linux binaries, the 16-bit system APIs are 32-bit clean and C callable, as one might expect them to be. All the tapdancing is to support existing LX binaries in the loader and bridge between the 32-bit clean APIs and existing 16-bit code that expects to call 16-bit APIs. This was a staggering amount of effort, but yay! Other fixes and improvements probably leaked into this commit, as a lot of code got touched and a lot of research and debugging took place.
icculus · Oct 27, 2016 · 26a5298 · 26a5298
1 parent 29696db
commit 26a5298
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Showing 10 changed files with 694 additions and 57 deletions.
diff --git a/cvtasm.pl b/cvtasm.pl
@@ -0,0 +1,25 @@
+#!/usr/bin/perl -w
+
+# run this on the output from ndisasm.
+
+use warnings;
+use strict;
+
+while (<>) {
+    chomp;
+    my ($bytes, $asm) = /\A.*?\s+(.*?)\s+(.*)\Z/;
+    my $first = 1;
+    while ($bytes ne '') {
+        $bytes =~ s/\A(..)//;
+        my $hex = $1;
+        if ($first and ($bytes eq '')) {
+            print("    *(ptr++) = 0x$hex;  /* $asm */\n");
+        } elsif ($first) {
+            print("    *(ptr++) = 0x$hex;  /* $asm... */\n");
+        } else {
+            print("    *(ptr++) = 0x$hex;  /*  ...$asm */\n");
+        }
+        $first = 0;
+    }
+}
+
diff --git a/lx_loader.c b/lx_loader.c
diff --git a/lx_loader.h b/lx_loader.h
@@ -129,15 +129,18 @@ typedef struct LxResourceTableEntry
 
 typedef struct LxMmaps
 {
+    void *mapped;
     void *addr;
     size_t size;
+    uint16 alias;  // 16:16 alias, if one.
 } LxMmaps;
 
 typedef struct LxExport
 {
     uint32 ordinal;
     const char *name;  // can be NULL
     void *addr;
+    const LxMmaps *object;
 } LxExport;
 
 struct LxModule;
@@ -149,6 +152,7 @@ struct LxModule
     char name[256];  // !!! FIXME: allocate this.
     LxModule **dependencies;
     LxMmaps *mmaps;
+
     const LxExport *exports;
     uint32 num_exports;
     void *nativelib;
@@ -202,14 +206,23 @@ typedef struct LxLoaderState
 {
     LxModule *loaded_modules;
     LxModule *main_module;
+    uint8 main_tibspace[LXTIBSIZE];
     LxPIB pib;
     int subprocess;
     int running;
+    int trace_native;
+    uint16 original_cs;
+    uint16 original_ss;
+    uint16 original_ds;
+    uint32 ldt[8192];
     uint32 *tlspage;
     uint32 tlsmask;  // one bit for each TLS slot in use.
     uint8 tlsallocs[32];  // number of TLS slots allocated in one block, indexed by starting block (zero if not the starting block).
     uint16 (*initOs2Tib)(uint8 *tibspace, void *_topOfStack, const size_t stacklen, const uint32 tid);
     void (*deinitOs2Tib)(const uint16 selector);
+    int (*findSelector)(const uint32 addr, uint16 *outselector, uint16 *outoffset);
+    void (*freeSelector)(const uint16 selector);
+    void *(*convert1616to32)(const uint32 addr1616);
     LxModule *(*loadModule)(const char *modname);
     int (*locatePathCaseInsensitive)(char *buf);
     char *(*makeUnixPath)(const char *os2path, uint32 *err);

diff --git a/native/doscalls.c b/native/doscalls.c
@@ -1,23 +1,18 @@
-#define _POSIX_C_SOURCE 199309
-#define _BSD_SOURCE
-#define _GNU_SOURCE
+#include "os2native.h"
+#include "doscalls.h"
+
 #include <unistd.h>
 #include <limits.h>
 #include <time.h>
 #include <dirent.h>
 #include <fcntl.h>
-#include <pthread.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <sys/sysinfo.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
-#include <sys/mman.h>
-
-#include "os2native.h"
-#include "doscalls.h"
 
 static LxLoaderState *GLoaderState = NULL;
 
@@ -100,6 +95,11 @@ typedef struct
 static DirFinder GHDir1;
 
 
+// !!! FIXME:
+#undef TRACE_NATIVE
+#define TRACE_NATIVE(...) do { if (GLoaderState->trace_native) { fprintf(stderr, "2INE TRACE [%lu]: ", (unsigned long) pthread_self()); fprintf(stderr, __VA_ARGS__); fprintf(stderr, ";\n"); } } while (0)
+
+
 LX_NATIVE_MODULE_DEINIT({
     ExitListItem *next = GExitList;
     GExitList = NULL;
@@ -599,11 +599,32 @@ APIRET DosSetExceptionHandler(PEXCEPTIONREGISTRATIONRECORD rec)
     return NO_ERROR;
 } // DosSetExceptionHandler
 
-ULONG DosFlatToSel(PVOID ptr)
+ULONG _DosFlatToSel(PVOID ptr)
 {
     TRACE_NATIVE("DosFlatToSel(%p)", ptr);
-    return ((ULONG) ((size_t)ptr)) >> 16;  // !!! FIXME
-} // DosFlatToSel
+
+    uint16 selector = 0;
+    uint16 offset = 0;
+    if (!GLoaderState->findSelector((uint32) ptr, &selector, &offset)) {
+        fprintf(stderr, "Uhoh, ran out of LDT entries?!\n");
+        return 0;  // oh well, crash.
+    } // if
+
+    selector = (selector << 3) | 7;
+    return (((uint32)selector) << 16) | ((uint32) offset);
+} // _DosFlatToSel
+
+// DosFlatToSel() passes its argument in %eax, so a little asm to bridge that...
+__asm__ (
+    ".globl DosFlatToSel  \n\t"
+    ".type	DosFlatToSel, @function \n\t"
+    "DosFlatToSel:  \n\t"
+    "    pushl %eax  \n\t"
+    "    call _DosFlatToSel  \n\t"
+    "    addl $4, %esp  \n\t"
+    "    ret  \n\t"
+	".size	_DosFlatToSel, .-_DosFlatToSel  \n\t"
+);
 
 APIRET DosSetSignalExceptionFocus(BOOL32 flag, PULONG pulTimes)
 {

diff --git a/native/doscalls.h b/native/doscalls.h
@@ -386,7 +386,7 @@ APIRET OS2API DosExitList(ULONG ordercode, PFNEXITLIST pfn);
 APIRET OS2API DosCreateEventSem(PSZ pszName, PHEV phev, ULONG flAttr, BOOL32 fState);
 APIRET OS2API DosCreateMutexSem(PSZ pszName, PHMTX phmtx, ULONG flAttr, BOOL32 fState);
 APIRET OS2API DosSetExceptionHandler(PEXCEPTIONREGISTRATIONRECORD pERegRec);
-ULONG OS2API DosFlatToSel(PVOID ptr);
+ULONG OS2API DosFlatToSel(VOID);
 APIRET OS2API DosSetSignalExceptionFocus(BOOL32 flag, PULONG pulTimes);
 APIRET OS2API DosSetRelMaxFH(PLONG pcbReqCount, PULONG pcbCurMaxFH);
 APIRET OS2API DosAllocMem(PPVOID ppb, ULONG cb, ULONG flag);

diff --git a/native/os2native.h b/native/os2native.h
@@ -1,11 +1,16 @@
-#ifndef _INCL_NATIVE_H_
-#define _INCL_NATIVE_H_
+#ifndef _INCL_OS2NATIVE_H_
+#define _INCL_OS2NATIVE_H_
 
+#define _POSIX_C_SOURCE 199309
+#define _BSD_SOURCE
+#define _GNU_SOURCE
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <assert.h>
 #include <pthread.h>
 #include <errno.h>
+#include <sys/mman.h>
 
 #include "os2types.h"
 #include "os2errors.h"
@@ -28,7 +33,7 @@ void OS2EXPORT lxNativeModuleDeinit(void);
         initcode; \
         static const LxExport lx_native_exports[] = {
 
-#define LX_NATIVE_EXPORT(fn, ord) { ord, #fn, fn }
+#define LX_NATIVE_EXPORT(fn, ord) { ord, #fn, fn, NULL }
 
 #define LX_NATIVE_MODULE_INIT_END() \
     }; \
@@ -38,5 +43,5 @@ void OS2EXPORT lxNativeModuleDeinit(void);
 
 #endif
 
-// end of native.h ...
+// end of os2native.h ...