Simple memset/memcpy implementation

5 files changed, 54 insertions, 20 deletions

diff --git a/dos/Makefile b/dos/Makefile
index ac75bedf..b46a35f3 100644
--- a/dos/Makefile
+++ b/dos/Makefile
@@ -9,7 +9,7 @@ LDFLAGS	 = -T com16.ld
 SRCS     = syslinux.c printf.c conio.c skipatou.c atou.c malloc.c free.c \
 	   ../syslxmod.c ../bootsect_bin.c ../ldlinux_bin.c \
            $(wildcard ../libfat/*.c)
-OBJS	 = crt0.o $(patsubst %.c,%.o,$(notdir $(SRCS)))
+OBJS	 = crt0.o memcpy.o memset.o $(patsubst %.c,%.o,$(notdir $(SRCS)))
 
 .SUFFIXES: .c .o .i .s .S .elf .com
 
diff --git a/dos/memcpy.S b/dos/memcpy.S
new file mode 100644
index 00000000..f6d4fd2f
--- /dev/null
+++ b/dos/memcpy.S
@@ -0,0 +1,24 @@
+# $Id$
+#
+# memcpy.S
+#
+# Simple 16-bit memcpy() implementation
+#
+
+	.text
+	.code16
+	.globl memcpy
+	.type memcpy, @function
+memcpy:
+	cld
+	pushl %edi
+	pushl %esi
+	movw 12(%esp),%di
+	movw 16(%esp),%si
+	movw 20(%esp),%cx
+	rep ; movsb
+	popl %esi
+	popl %edi
+	ret
+
+	.size memcpy,.-memcpy
diff --git a/dos/memset.S b/dos/memset.S
new file mode 100644
index 00000000..a7f610a3
--- /dev/null
+++ b/dos/memset.S
@@ -0,0 +1,22 @@
+# $Id$
+#
+# memset.S
+#
+# Minimal 16-bit memset() implementation
+#
+
+	.text
+	.code16
+	.globl memset
+	.type memset, @function
+memset:
+	cld
+	pushl %edi
+	movw 8(%esp),%di
+	movb 12(%esp),%al
+	movw 16(%esp),%cx
+	rep ; stosb
+	popl %edi
+	ret
+
+	.size memset,.-memset
diff --git a/dos/string.h b/dos/string.h
index cee8e2e6..44f77dac 100644
--- a/dos/string.h
+++ b/dos/string.h
@@ -6,22 +6,10 @@
 #define _STRING_H
 
 /* Standard routines */
-static inline void *memcpy(void *__d, const void *__s, unsigned int __n)
-{
-  asm volatile("cld ; rep ; movsb"
-	       : "+D" (__d), "+S" (__s), "+c" (__n));
-  return __d;
-}
-
-static inline void *memset(void *__d, int __c, unsigned int __n)
-{
-  asm volatile("cld ; rep ; stosb"
-	       : "+D" (__d), "+a" (__c), "+c" (__n));
-  return __d;
-}
-
-#define strcpy(a,b)   __builtin_strcpy(a,b)
-#define strlen(a)     __builtin_strlen(a)
+#define memcpy(a,b,c)	__builtin_memcpy(a,b,c)
+#define memset(a,b,c)	__builtin_memset(a,b,c)
+#define strcpy(a,b)	__builtin_strcpy(a,b)
+#define strlen(a)	__builtin_strlen(a)
 
 /* This only returns true or false */
 static inline int memcmp(const void *__m1, const void *__m2, unsigned int __n)
diff --git a/dos/syslinux.c b/dos/syslinux.c
index dbab7bcc..820e1cbc 100644
--- a/dos/syslinux.c
+++ b/dos/syslinux.c
@@ -131,9 +131,9 @@ void set_attributes(const char *file, int attributes)
 /*
  * Version of the read_device function suitable for libfat
  */
-int libfat_xpread(void *pp, void *buf, size_t secsize, libfat_sector_t sector)
+int libfat_xpread(intptr_t pp, void *buf, size_t secsize, libfat_sector_t sector)
 {
-  read_device((int)pp, buf, 1, sector);
+  read_device(pp, buf, 1, sector);
   return secsize;
 }
 
@@ -208,7 +208,7 @@ int main(int argc, char *argv[])
    * this is supposed to be a simple, privileged version
    * of the installer.
    */
-  fs = libfat_open(libfat_xpread, (void *)dev_fd);
+  fs = libfat_open(libfat_xpread, dev_fd);
   ldlinux_cluster = libfat_searchdir(fs, 0, "LDLINUX SYS", NULL);
   secp = sectors;
   nsectors = 0;