dos: add memcpy_from_sl() and use it where appropriate

Add memcpy_from_sl() and use it to handle pointers into the payload
section.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/dos/getsetsl.c b/dos/getsetsl.c
index 5c1dbbd..67e954d 100644 (file)
--- a/dos/getsetsl.c
+++ b/dos/getsetsl.c
@@ -98,3 +98,20 @@ void memcpy_to_sl(void *dst, const void *src, size_t len)
                 : "r" (seg)
                 : "memory");
 }
+
+void memcpy_from_sl(void *dst, const void *src, size_t len)
+{
+    uint16_t seg;
+    uint16_t off;
+
+    seg = ds() + ((size_t)src >> 4);
+    off = (size_t)src & 15;
+
+    asm volatile("pushw %%ds ; "
+                "movw %3,%%ds ; "
+                "rep ; movsb ; "
+                "popw %%ds"
+                : "+D" (dst), "+S" (off), "+c" (len)
+                : "r" (seg)
+                : "memory");
+}

diff --git a/dos/syslinux.c b/dos/syslinux.c
index 744ec36..c935f8e 100755 (executable)
--- a/dos/syslinux.c
+++ b/dos/syslinux.c
@@ -1,7 +1,7 @@
 /* ----------------------------------------------------------------------- *
  *
  *   Copyright 1998-2008 H. Peter Anvin - All Rights Reserved
- *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
+ *   Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
  *
  *   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
@@ -30,6 +30,7 @@
 #include "setadv.h"
 #include "sysexits.h"
 #include "syslxopt.h"
+#include "syslxint.h"
 
 const char *program = "syslinux";      /* Name of program */
 uint16_t dos_version;
@@ -119,11 +120,9 @@ int rename(const char *oldname, const char *newname)
     return 0;
 }
 
-extern const char __payload_sseg[];
-uint16_t ldlinux_seg;
-
 ssize_t write_ldlinux(int fd)
 {
+    uint16_t ldlinux_seg = ((size_t)syslinux_ldlinux >> 4) + ds();
     uint32_t offset = 0;
     uint16_t rv;
     uint8_t err;
@@ -136,8 +135,8 @@ ssize_t write_ldlinux(int fd)
                      "movw %6,%%ds ; "
                      "int $0x21 ; "
                      "popw %%ds ; " "setc %0":"=bcdm" (err), "=a"(rv)
-                     :"a"(0x4000), "b"(fd), "c"(chunk), "d"(offset & 15),
-                     "SD"((uint16_t) (ldlinux_seg + (offset >> 4))));
+                     :"a"(0x4000), "b"(fd), "c"(chunk), "d" (offset & 15),
+                     "SD" ((uint16_t)(ldlinux_seg + (offset >> 4))));
        if (err || rv == 0)
            die("file write error");
        offset += rv;
@@ -178,7 +177,7 @@ uint16_t data_segment(void)
 
 void write_device(int drive, const void *buf, size_t nsecs, unsigned int sector)
 {
-    uint16_t errnum;
+    uint16_t errnum = 0x0001;
     struct diskio dio;
 
     dprintf("write_device(%d,%p,%u,%u)\n", drive, buf, nsecs, sector);
@@ -187,14 +186,17 @@ void write_device(int drive, const void *buf, size_t nsecs, unsigned int sector)
     dio.sectors = nsecs;
     dio.bufoffs = (uintptr_t) buf;
     dio.bufseg = data_segment();
-
-    /* Try FAT32-aware system call first */
-    asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
-                "1:"
-                : "=a" (errnum)
-                : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
-                  "S" (1), "m" (dio)
-                : "memory");
+    
+    if (dos_version >= 0x070a) {
+       /* Try FAT32-aware system call first */
+       asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
+                    "1:"
+                    : "=a" (errnum)
+                    : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
+                      "S" (1), "m" (dio)
+                    : "memory");
+       dprintf(" rv(7305) = %04x", errnum);
+    }
 
     /* If not supported, try the legacy system call (int2526.S) */
     if (errnum == 0x0001)
@@ -206,9 +208,9 @@ void write_device(int drive, const void *buf, size_t nsecs, unsigned int sector)
     }
 }
 
-void read_device(int drive, const void *buf, size_t nsecs, unsigned int sector)
+void read_device(int drive, void *buf, size_t nsecs, unsigned int sector)
 {
-    uint16_t errnum;
+    uint16_t errnum = 0x0001;
     struct diskio dio;
 
     dprintf("read_device(%d,%p,%u,%u)\n", drive, buf, nsecs, sector);
@@ -217,13 +219,16 @@ void read_device(int drive, const void *buf, size_t nsecs, unsigned int sector)
     dio.sectors = nsecs;
     dio.bufoffs = (uintptr_t) buf;
     dio.bufseg = data_segment();
-
-    /* Try FAT32-aware system call first */
-    asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
-                "1:"
-                : "=a" (errnum)
-                : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
-                  "S" (0), "m" (dio));
+    
+    if (dos_version >= 0x070a) {
+       /* Try FAT32-aware system call first */
+       asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
+                    "1:"
+                    : "=a" (errnum)
+                    : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
+                      "S" (0), "m" (dio));
+       dprintf(" rv(7305) = %04x", errnum);
+    }
 
     /* If not supported, try the legacy system call (int2526.S) */
     if (errnum == 0x0001)
@@ -600,9 +605,6 @@ int main(int argc, char *argv[])
     int raid_mode = 0;
     int patch_sectors;
 
-    ldlinux_seg = (size_t) __payload_sseg + data_segment();
-printf("SHAO seg: 0x%04x\n", ldlinux_seg);
-
     dprintf("argv = %p\n", argv);
     for (i = 0; i <= argc; i++)
        dprintf("argv[%d] = %p = \"%s\"\n", i, argv[i], argv[i]);
@@ -758,7 +760,6 @@ printf("SHAO seg: 0x%04x\n", ldlinux_seg);
        }
     }
 
-printf("Foo: %p\n", syslinux_ldlinux);
     /*
      * Patch ldlinux.sys and the boot sector
      */
@@ -770,14 +771,9 @@ printf("Foo: %p\n", syslinux_ldlinux);
      */
     /* lock_device(3); -- doesn't seem to be needed */
     for (i = 0; i < patch_sectors; i++) {
-       uint16_t si, di, cx;
-       si = 0;
-       di = (size_t) sectbuf;
-       cx = SECTOR_SIZE >> 2;
-       asm volatile ("movw %3,%%fs ; fs ; rep ; movsl":"+S" (si), "+D"(di),
-                     "+c"(cx)
-                     :"abd"((uint16_t)
-                            (ldlinux_seg + (i << (SECTOR_SHIFT - 4)))));
+       unsigned char *p = syslinux_ldlinux;
+       memcpy_from_sl(sectbuf, p, SECTOR_SIZE);
+       p += SECTOR_SIZE;
        write_device(dev_fd, sectbuf, 1, sectors[i]);
     }
 

diff --git a/libinstaller/syslxint.h b/libinstaller/syslxint.h
index b8e872a..14a7fc2 100644 (file)
--- a/libinstaller/syslxint.h
+++ b/libinstaller/syslxint.h
@@ -137,6 +137,7 @@ void set_16_sl(uint16_t * p, uint16_t v);
 void set_32_sl(uint32_t * p, uint32_t v);
 void set_64_sl(uint64_t * p, uint64_t v);
 void memcpy_to_sl(void *dst, const void *src, size_t len);
+void memcpy_from_sl(void *dst, const void *src, size_t len);
 
 #else
 
@@ -150,6 +151,7 @@ void memcpy_to_sl(void *dst, const void *src, size_t len);
 #define set_32_sl(x,y)                 set_32(x,y)
 #define set_64_sl(x,y)                 set_64(x,y)
 #define memcpy_to_sl(d,s,l)    memcpy(d,s,l)
+#define memcpy_from_sl(d,s,l)  memcpy(d,s,l)
 
 #endif