memdisk varieties: Allow for multiple memdisk installable hooks

This patch "sets the stage" for the memdisk kernel to include different
"installables": versions of the memdisk hooks.

This patch splits the case of the EDD-compiled hook from the non-EDD-compiled
hook.  Both are available inside the kernel, and the kernel chooses which one
to install based on the command-line.

It's possible that other, slightly modified versions of the memdisk hook could
be useful to have...

diff --git a/memdisk/Makefile b/memdisk/Makefile
index 3776731..54b08ba 100644 (file)
--- a/memdisk/Makefile
+++ b/memdisk/Makefile
@@ -20,7 +20,7 @@ LDFLAGS  = $(GCCOPT) -g
 INCLUDE  = -I$(topdir)/com32/include
 NASM     = nasm
 NASMOPT  = -O9999
-NFLAGS   = -dDATE='"$(DATE)"' -dWITH_EDD
+NFLAGS   = -dDATE='"$(DATE)"'
 NINCLUDE =
 
 SRCS    = $(wildcard *.asm *.c *.h)
@@ -38,11 +38,11 @@ endif
 # Important: init.o16 must be first!!
 OBJS16   = init.o16 init32.o
 OBJS32   = start32.o setup.o msetup.o e820func.o conio.o memcpy.o memset.o \
-           unzip.o memdisk.o
+           unzip.o memdisk_chs.o memdisk_edd.o
 
 CSRC     = setup.c msetup.c e820func.c conio.c unzip.c
 SSRC     = start32.S memcpy.S memset.S
-NASMSRC  = memdisk.asm memdisk16.asm
+NASMSRC  = memdisk_chs.asm memdisk_edd.asm memdisk16.asm
 
 all: memdisk # e820test
 
@@ -56,7 +56,7 @@ clean: tidy
 spotless: clean
        rm -f memdisk .depend
 
-%.o: %.asm
+memdisk16.o: memdisk16.asm
        $(NASM) $(NASMOPT) $(NFLAGS) $(NINCLUDE) -f elf -l $*.lst -o $@ $<
 
 %.o: %.s
@@ -92,6 +92,9 @@ spotless: clean
 %.bin: %.asm
        $(NASM) -f bin $(NASMOPT) $(NFLAGS) $(NINCLUDE) -o $@ -l $*.lst $<
 
+memdisk_%.o: memdisk_%.bin
+       $(LD) -r -b binary -o $@ $<
+
 memdisk16.elf: $(OBJS16)
        $(LD) -Ttext 0 -o $@ $^
 
@@ -107,9 +110,6 @@ memdisk: memdisk16.bin memdisk32.bin postprocess.pl
 e820test: e820test.c e820func.c msetup.c
        $(CC) -m32 -g -W -Wall -DTEST -o $@ $^
 
-memdisk.o: memdisk.bin
-       $(LD) -r -b binary -o $@ $<
-
 .depend:
        rm -f .depend
        for csrc in *.c ; do $(CC) $(INCLUDE) $(CFLAGS) -MM $$csrc >> .depend ; done

diff --git a/memdisk/memdisk.asm b/memdisk/memdisk.inc
similarity index 99%
rename from memdisk/memdisk.asm
rename to memdisk/memdisk.inc
index 0d48961..2b5b4e0 100644 (file)
--- a/memdisk/memdisk.asm
+++ b/memdisk/memdisk.inc
@@ -1,7 +1,7 @@
 ; -*- fundamental -*- (asm-mode sucks)
 ; ****************************************************************************
 ;
-;  memdisk.asm
+;  memdisk.inc
 ;
 ;  A program to emulate an INT 13h disk BIOS from a "disk" in extended
 ;  memory.

diff --git a/memdisk/memdisk_chs.asm b/memdisk/memdisk_chs.asm
new file mode 100644 (file)
index 0000000..daa5c0a
--- /dev/null
+++ b/memdisk/memdisk_chs.asm
@@ -0,0 +1 @@
+%include "memdisk.inc"

diff --git a/memdisk/memdisk_edd.asm b/memdisk/memdisk_edd.asm
new file mode 100644 (file)
index 0000000..97d3fe9
--- /dev/null
+++ b/memdisk/memdisk_edd.asm
@@ -0,0 +1,2 @@
+%define WITH_EDD
+%include "memdisk.inc"

diff --git a/memdisk/setup.c b/memdisk/setup.c
index 7b1f456..1cd5e11 100644 (file)
--- a/memdisk/setup.c
+++ b/memdisk/setup.c
@@ -22,8 +22,12 @@ const char memdisk_version[] =
 const char copyright[] =
 "Copyright " FIRSTYEAR "-" YEAR_STR " H. Peter Anvin";
 
-extern const char _binary_memdisk_bin_start[], _binary_memdisk_bin_end[];
-extern const char _binary_memdisk_bin_size[]; /* Weird, I know */
+extern const char _binary_memdisk_chs_bin_start[];
+extern const char _binary_memdisk_chs_bin_end[];
+extern const char _binary_memdisk_chs_bin_size[];
+extern const char _binary_memdisk_edd_bin_start[];
+extern const char _binary_memdisk_edd_bin_end[];
+extern const char _binary_memdisk_edd_bin_size[];
 
 struct memdisk_header {
   uint16_t int13_offs;
@@ -93,7 +97,6 @@ struct patch_area {
   uint16_t dpt_ptr;
   /* End of the official MemDisk_Info */
   uint8_t  maxint13func;
-#define MAXINT13_NOEDD 0x16
   uint8_t  _pad2;
 
   uint16_t _pad3;
@@ -598,7 +601,8 @@ void *sys_bounce;
 
 __cdecl void setup(__cdecl syscall_t cs_syscall, void *cs_bounce)
 {
-  unsigned int bin_size = (int) &_binary_memdisk_bin_size;
+  unsigned int bin_size;
+  char *memdisk_hook;
   struct memdisk_header *hptr;
   struct patch_area *pptr;
   uint16_t driverseg;
@@ -610,7 +614,7 @@ __cdecl void setup(__cdecl syscall_t cs_syscall, void *cs_bounce)
   com32sys_t regs;
   uint32_t ramdisk_image, ramdisk_size;
   int bios_drives;
-  int do_edd = -1;             /* -1 = default, 0 = no, 1 = yes */
+  int do_edd = 1;              /* 0 = no, 1 = yes, default is yes */
   int no_bpt;                  /* No valid BPT presented */
 
   /* Set up global variables */
@@ -649,13 +653,22 @@ __cdecl void setup(__cdecl syscall_t cs_syscall, void *cs_bounce)
   else
     do_edd = (geometry->driveno & 0x80) ? 1 : 0;
 
+  /* Choose the appropriate installable memdisk hook */
+  if (do_edd) {
+    bin_size = (int) &_binary_memdisk_edd_bin_size;
+    memdisk_hook = (char *) &_binary_memdisk_edd_bin_start;
+  } else {
+    bin_size = (int) &_binary_memdisk_chs_bin_size;
+    memdisk_hook = (char *) &_binary_memdisk_chs_bin_start;
+  }
+
   /* Reserve the ramdisk memory */
   insertrange(ramdisk_image, ramdisk_size, 2, 1);
   parse_mem();                 /* Recompute variables */
 
   /* Figure out where it needs to go */
-  hptr = (struct memdisk_header *) &_binary_memdisk_bin_start;
-  pptr = (struct patch_area *)(_binary_memdisk_bin_start + hptr->patch_offs);
+  hptr = (struct memdisk_header *) memdisk_hook;
+  pptr = (struct patch_area *)(memdisk_hook + hptr->patch_offs);
 
   dosmem_k = rdz_16(BIOS_BASEMEM);
   pptr->olddosmem = dosmem_k;
@@ -726,10 +739,6 @@ __cdecl void setup(__cdecl syscall_t cs_syscall, void *cs_bounce)
   }
   puts(" access to high memory\n");
 
-  /* pptr->maxint13func defaults to EDD enabled, if compiled in */
-  if (!do_edd)
-    pptr->maxint13func = MAXINT13_NOEDD;
-
   /* Set up a drive parameter table */
   if ( geometry->driveno & 0x80 ) {
     /* Hard disk */
@@ -898,7 +907,7 @@ __cdecl void setup(__cdecl syscall_t cs_syscall, void *cs_bounce)
     hptr = (struct memdisk_header *)dpp;
 
     /* Actually copy to low memory */
-    dpp = mempcpy(dpp, &_binary_memdisk_bin_start, bin_size);
+    dpp = mempcpy(dpp, memdisk_hook, bin_size);
     dpp = mempcpy(dpp, ranges, (nranges+1)*sizeof(ranges[0]));
     dpp = mempcpy(dpp, shdr->cmdline, cmdlinelen+1);
   }