Plt

fdpp/clang.mak

@@ -31,7 +31,7 @@ PKG_CONFIG ?= pkg-config
 
 TARGETOPT = -std=c++11 -c -fno-threadsafe-statics -fpic
 # _XTRA should go at the end of cmd line
-TARGETOPT_XTRA = -Wno-format-invalid-specifier
+TARGETOPT_XTRA = -Wno-format-invalid-specifier -Wno-c99-designator
 
 DEBUG_MODE ?= 1
 EXTRA_DEBUG ?= 0

fdpp/elf.c

@@ -142,9 +142,8 @@ void elf_close(void *arg)
     free(state);
 }
 
-void *elf_getsym(void *arg, const char *name)
+static int do_getsymoff(struct elfstate *state, const char *name)
 {
-    struct elfstate *state = (struct elfstate *)arg;
     Elf_Data *data;
     int count, i;
 
@@ -156,8 +155,23 @@ void *elf_getsym(void *arg, const char *name)
         gelf_getsym(data, i, &sym);
         if (strcmp(elf_strptr(state->elf, state->symtab_shdr.sh_link,
                 sym.st_name), name) == 0)
-            return state->addr + state->load_offs + sym.st_value;
+            return sym.st_value;
     }
 
-    return NULL;
+    return -1;
+}
+
+void *elf_getsym(void *arg, const char *name)
+{
+    struct elfstate *state = (struct elfstate *)arg;
+    int off = do_getsymoff(state, name);
+    if (off == -1)
+        return NULL;
+    return state->addr + state->load_offs + off;
+}
+
+int elf_getsymoff(void *arg, const char *name)
+{
+    struct elfstate *state = (struct elfstate *)arg;
+    return do_getsymoff(state, name);
 }

fdpp/elf_priv.h

@@ -2,3 +2,4 @@ void *elf_open(const char *name);
 void elf_reloc(void *arg, uint16_t seg);
 void elf_close(void *arg);
 void *elf_getsym(void *arg, const char *name);
+int elf_getsymoff(void *arg, const char *name);

fdpp/makefile

@@ -121,7 +121,7 @@ GEN_HEADERS = thunk_calls.h thunk_asms.h rel.h
 GEN_HEADERS_FD = glob_asmdefs.h
 GEN_ASMS = plt.asm cdata.asm
 # dont change file order in GEN_TMP as it matches the gen script
-GEN_TMP = thunk_calls.tmp thunk_asms.tmp plt.inc plt_asmc.inc plt_asmp.inc
+GEN_TMP = thunk_calls.tmp thunk_asms.tmp plt.inc plt_asmc.h plt_asmp.h
 GEN_CC = $(CFILES:.c=.cc)
 INITHEADERS = $(SRC)/init-mod.h $(SRC)/init-dat.h
 HEADERS=$(HDRS) $(SRC)/globals.h $(SRC)/proto.h $(INITHEADERS) $(PPHDRS)
@@ -179,7 +179,7 @@ $(FDPP_COBJS): %.o: $(srcdir)/%.c $(PPHDRS) $(srcdir)/makefile
 	$(CC) $(CLCFLAGS) -I . -o $@ $<
 
 thunks.o: $(EXT_H) $(GIT_REV)
-thunks_a.o: $(SRC)/glob_asm.h $(srcdir)/glob_tmpl.h
+thunks_a.o: $(SRC)/glob_asm.h $(srcdir)/glob_tmpl.h plt_asmc.h plt_asmp.h
 $(FDPP_CCOBJS): %.o: $(srcdir)/%.cc $(GEN_HEADERS) $(PPHDRS) $(srcdir)/makefile
 	$(CC) $(CFLAGS) -o $@ $<
 
@@ -205,7 +205,7 @@ $(FDPPLIB): $(OBJECTS) $(FDPP_COBJS) $(FDPP_CCOBJS) $(FDPP_CPPOBJS)
 $(FDPPDEVL): $(FDPPLIB)
 	ln -sf $< $@
 
-plt.o: plt.asm plt.inc plt_asmc.inc plt_asmp.inc $(SRC)/segs.inc
+plt.o: plt.asm plt.inc $(SRC)/segs.inc
 
 plt.asm: $(srcdir)/plt.S $(SRC)/glob_asm.h $(TOP)/include/fdpp/bprm.h \
    $(srcdir)/thunks_priv.h $(srcdir)/makefile
@@ -224,7 +224,7 @@ $(filter %.tmp,$(GEN_TMP)): $(SRC)/proto.h
 	$(pars)
 plt.inc: thunk_calls.tmp
 	$(pars)
-plt_asmc.inc plt_asmp.inc: thunk_asms.tmp
+plt_asmc.h plt_asmp.h: thunk_asms.tmp
 	$(pars)
 
 thunk_calls.h: thunk_calls.tmp parsers/thunk_gen

fdpp/parsers/parse_decls.sh

@@ -19,12 +19,12 @@ gen_asms_tmp() {
 
 gen_plt_asmc() {
 	grep ASMFUNC $1 | \
-		sed -E 's/([0-9]+)[[:blank:]]+([^[:blank:]\(]+[[:blank:]]+)+([^ \(]+) *\(.+/asmcsym \3, \1/'
+		sed -E 's/([0-9]+)[[:blank:]]+([^[:blank:]\(]+[[:blank:]]+)+([^ \(]+) *\(.+/ASMCSYM\(\3, \1\)/'
 }
 
 gen_plt_asmp() {
 	grep ASMPASCAL $1 | tr '[:lower:]' '[:upper:]' | \
-		sed -E 's/([0-9]+)[[:blank:]]+([^[:blank:]\(]+[[:blank:]]+)+([^ \(]+) *\(.+/asmpsym \3, \1/'
+		sed -E 's/([0-9]+)[[:blank:]]+([^[:blank:]\(]+[[:blank:]]+)+([^ \(]+) *\(.+/ASMPSYM\(\3, \1\)/'
 }
 
 case "$1" in

fdpp/plt.S

@@ -1,6 +1,6 @@
 /*
  *  FDPP - freedos port to modern C++
- *  Copyright (C) 2018  Stas Sergeev (stsp)
+ *  Copyright (C) 2018-2023  Stas Sergeev (stsp)
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -20,8 +20,6 @@
 #include "bprm.h"
 %include "segs.inc"
 
-%define _SEG(s) TGROUP
-
 extern _BootParamSeg
 
 segment _BSS
@@ -60,23 +58,6 @@ segment %3
 
 %include "plt.inc"
 
-%macro asmcsym 2
-    dw %2
-    extern _%1
-    dw _%1, _SEG(_%1)
-%endmacro
-
-%macro asmpsym 2
-    dw %2
-    extern %1
-    dw %1, _SEG(%1)
-%endmacro
-
-%macro asmsym 1
-    extern _%1
-    dw _%1, _SEG(_%1)
-%endmacro
-
 %macro nearwrp 0
     push bp
     mov bp, sp
@@ -116,25 +97,6 @@ segment %3
     retf 2
 %endmacro
 
-segment INIT_TEXT
-
-__asm_callsymtab_start:
-%include "plt_asmc.inc"
-%include "plt_asmp.inc"
-__asm_callsymtab_end:
-
-#define __ASM(t, n) asmsym n
-#define __ASM_FAR(t, n) asmsym n
-#define __ASM_NEAR(t, n) asmsym n
-#define __ASM_ARR(t, n, l) asmsym n
-#define __ASM_ARRI(t, n) asmsym n
-#define __ASM_ARRI_F(t, n) asmsym n
-#define __ASM_FUNC(n) asmsym n
-#define SEMIC
-__asm_symtab_start:
-#include <glob_asm.h>
-__asm_symtab_end:
-
 segment HMA_TEXT
 
 near_wrp:
@@ -147,40 +109,11 @@ init_near_wrp:
 
     global plt_init
 plt_init:
-    push bp
-    mov bp, sp
-
     ; copy plt entry
     mov ax, FDPP_BS_SEG
     mov es, ax
     mov ax, [es:FDPP_BS_OFF+FDPP_PLT_OFFSET]
     mov bx, [es:FDPP_BS_OFF+FDPP_PLT_OFFSET+2]
     mov [fdpp_plt], ax
     mov [fdpp_plt + 2], bx
-
-    mov al, 0 ; reserved
-    mov ah, FDPP_KERNEL_VERSION
-    mov bx, 0 ; reserved
-    ; fill in struct fdpp_symtab
-    push word IGROUP
-    push word init_near_wrp           ; near_wrp[1]
-    push word TGROUP
-    push word near_wrp                ; near_wrp[0]
-    push word __asm_callsymtab_end - __asm_callsymtab_start  ; calltab_len
-    push word IGROUP
-    push word __asm_callsymtab_start  ; calltab
-    push word __asm_symtab_end - __asm_symtab_start  ; symtab_len
-    push word IGROUP
-    push word __asm_symtab_start      ; symtab
-    ; fdpp_symtab filled
-    mov si, sp
-
-    push ds
-    mov di, DGROUP
-    mov ds, di
-    call far [es:FDPP_BS_OFF+FDPP_PLT_OFFSET+4]
-    pop ds
-
-    mov sp, bp
-    pop bp
     ret

fdpp/thunks.cc

@@ -1,6 +1,6 @@
 /*
  *  FDPP - freedos port to modern C++
- *  Copyright (C) 2018  Stas Sergeev (stsp)
+ *  Copyright (C) 2018-2023  Stas Sergeev (stsp)
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -36,15 +36,14 @@
 static struct fdpp_api *fdpp;
 
 struct asm_dsc_s {
-    UWORD num;
     UWORD off;
     UWORD seg;
 };
 struct asm_dsc_s *asm_tab;
-static int asm_tab_len;
+#define asm_tab_len num_cthunks
 static farhlp sym_tab;
-static struct far_s *near_wrp;
 #define num_wrps 2
+static struct far_s near_wrp[num_wrps];
 static int recur_cnt;
 
 enum { ASM_OK, ASM_NORET, ASM_ABORT, PING_ABORT };
@@ -132,35 +131,6 @@ int is_dos_space(const void *ptr)
     return fdpp->is_dos_space(ptr);
 }
 
-static int FdppSetAsmThunks(struct far_s *ptrs, int len)
-{
-    int i;
-    int exp = num_athunks;
-
-    if (len != exp) {
-        fdprintf("len=%i expected %i\n", len, exp);
-        return -1;
-    }
-
-    farhlp_init(&sym_tab);
-    for (i = 0; i < len; i++) {
-        *asm_thunks[i].ptr = ptrs[i];
-        /* there are conflicts, for example InitTextStart will collide
-         * with the first sym. So use _replace. */
-        store_far_replace(&sym_tab, resolve_segoff(ptrs[i]), ptrs[i]);
-    }
-
-    return 0;
-}
-
-struct fdpp_symtab {
-    struct far_s symtab;
-    uint16_t symtab_len;
-    struct far_s calltab;
-    uint16_t calltab_len;
-    struct far_s near_wrp[2];
-};
-
 static void do_relocs(UWORD old_seg, uint8_t *start_p, uint8_t *end_p,
         uint16_t delta)
 {
@@ -200,37 +170,9 @@ static void do_relocs(UWORD old_seg, uint8_t *start_p, uint8_t *end_p,
     fdlogprintf("processed %i relocs\n", reloc);
 }
 
-static void FdppSetSymTab(struct fdpp_symtab *symtab)
-{
-    int err;
-    struct far_s *thtab = (struct far_s *)resolve_segoff(symtab->symtab);
-    int stab_len = symtab->symtab_len / sizeof(struct far_s);
-
-    free(near_wrp);
-    near_wrp = (struct far_s *)malloc(sizeof(struct far_s) * num_wrps);
-    memcpy(near_wrp, symtab->near_wrp, sizeof(struct far_s) * num_wrps);
-    free(asm_tab);
-    asm_tab = (struct asm_dsc_s *)malloc(symtab->calltab_len);
-    memcpy(asm_tab, resolve_segoff(symtab->calltab), symtab->calltab_len);
-    asm_tab_len = symtab->calltab_len / sizeof(struct asm_dsc_s);
-    err = FdppSetAsmThunks(thtab, stab_len);
-    ___assert(!err);
-}
-
 int FdppCtrl(int idx, struct vm86_regs *regs)
 {
-#define DL_SET_SYMTAB 0
-    switch (idx) {
-    case DL_SET_SYMTAB:
-        if (HI_BYTE(regs->eax) != FDPP_KERNEL_VERSION) {
-            fdloudprintf("\nfdpp version mismatch: expected %i, got %i\n",
-                    FDPP_KERNEL_VERSION, HI_BYTE(regs->eax));
-            _fail();
-        }
-        FdppSetSymTab(
-                (struct fdpp_symtab *)so2lin(regs->ss, LO_WORD(regs->esi)));
-        return 0;
-    }
+    // so empty then???
     return -1;
 }
 
@@ -354,16 +296,8 @@ static void _call_wrp(FdppAsmCall_t call, struct vm86_regs *regs,
 static uint32_t _do_asm_call_far(int num, uint8_t *sp, uint8_t len,
         FdppAsmCall_t call)
 {
-    int i;
-
-    for (i = 0; i < asm_tab_len; i++) {
-        if (asm_tab[i].num == num) {
-            _call_wrp(call, &s_regs, asm_tab[i].seg, asm_tab[i].off, sp, len);
-            return (LO_WORD(s_regs.edx) << 16) | LO_WORD(s_regs.eax);
-        }
-    }
-    ___assert(0);
-    return -1;
+    _call_wrp(call, &s_regs, asm_tab[num].seg, asm_tab[num].off, sp, len);
+    return (LO_WORD(s_regs.edx) << 16) | LO_WORD(s_regs.eax);
 }
 
 static uint16_t find_wrp(int init, uint16_t seg)
@@ -375,21 +309,13 @@ static uint16_t find_wrp(int init, uint16_t seg)
 static uint32_t _do_asm_call(int num, int init, uint8_t *sp, uint8_t len,
         FdppAsmCall_t call)
 {
-    int i;
-
-    for (i = 0; i < asm_tab_len; i++) {
-        if (asm_tab[i].num == num) {
-            uint16_t wrp = find_wrp(init, asm_tab[i].seg);
-            LO_WORD(s_regs.eax) = asm_tab[i].off;
-            /* argpack should be aligned */
-            ___assert(!(len & 1));
-            LO_WORD(s_regs.ecx) = len >> 1;
-            _call_wrp(call, &s_regs, asm_tab[i].seg, wrp, sp, len);
-            return (LO_WORD(s_regs.edx) << 16) | LO_WORD(s_regs.eax);
-        }
-    }
-    ___assert(0);
-    return -1;
+    uint16_t wrp = find_wrp(init, asm_tab[num].seg);
+    LO_WORD(s_regs.eax) = asm_tab[num].off;
+    /* argpack should be aligned */
+    ___assert(!(len & 1));
+    LO_WORD(s_regs.ecx) = len >> 1;
+    _call_wrp(call, &s_regs, asm_tab[num].seg, wrp, sp, len);
+    return (LO_WORD(s_regs.edx) << 16) | LO_WORD(s_regs.eax);
 }
 
 static void asm_call(struct vm86_regs *regs, uint16_t seg,
@@ -784,8 +710,36 @@ void *FdppKernelLoad(const char *dname, int *len, struct fdpp_bss_list **bss)
 
 const void *FdppKernelReloc(void *handle, uint16_t seg)
 {
+    int i;
+    far_s f;
     struct krnl_hndl *h = (struct krnl_hndl *)handle;
     elf_reloc(h->elf, seg);
+
+    farhlp_init(&sym_tab);
+    f.seg = seg;
+    for (i = 0; i < num_athunks; i++) {
+        int off = elf_getsymoff(h->elf, asm_thunks[i].name);
+        assert(off != -1);
+        f.off = off;
+        *asm_thunks[i].ptr = f;
+        store_far_replace(&sym_tab, resolve_segoff(f), f);
+    }
+
+    asm_tab = (struct asm_dsc_s *)malloc(num_cthunks *
+               sizeof(struct asm_dsc_s *));
+    for (i = 0; i < num_cthunks; i++) {
+        int off = elf_getsymoff(h->elf, asm_cthunks[i].name);
+        assert(off != -1);
+        assert(asm_cthunks[i].name);
+        asm_tab[i].seg = seg;
+        asm_tab[i].off = off;
+    }
+
+    f.off = elf_getsymoff(h->elf, "near_wrp");
+    near_wrp[0] = f;
+    f.off = elf_getsymoff(h->elf, "init_near_wrp");
+    near_wrp[1] = f;
+
     return h->start;
 }