It seems to work now, but fd appears to be buggy???

diff --git a/ldlinux.asm b/ldlinux.asm
index ab44822..886706c 100644 (file)
--- a/ldlinux.asm
+++ b/ldlinux.asm
@@ -1503,8 +1503,8 @@ get_next_opt:   lodsb
                 push si                         ; mangle_dir mangles si
                 call mangle_name                ; Mangle ramdisk name
                 pop si
-               cmp byte [InitRD],' '           ; Null filename?
-                seta byte [initrd_flag]         ; Set flag if not
+               cmp byte [es:InitRD],' '        ; Null filename?
+                seta byte [es:initrd_flag]     ; Set flag if not
 not_initrd:     pop es                          ; Restore ES->real_mode_seg
 skip_this_opt:  lodsb                           ; Load from command line
                 cmp al,' '
@@ -1526,7 +1526,7 @@ is_vga_cmd:
                 je vc0
                 call parseint                   ; vga=<number>
                jc skip_this_opt                ; Not an integer
-vc0:           mov [es:bs_vidmode],bx          ; Set video mode
+vc0:           mov [bs_vidmode],bx             ; Set video mode
                jmp short skip_this_opt
 is_mem_cmd:
                 add si,byte 4
@@ -1537,7 +1537,7 @@ is_mem_cmd:
                cmp ebx,14*1024                 ; Only trust < 15M point
                 jna memcmd_fair
                mov bx,14*1024
-memcmd_fair:    mov [HighMemSize],bx
+memcmd_fair:    mov [es:HighMemSize],bx
                jmp short skip_this_opt
 cmdline_end:
                 push cs                         ; Restore standard DS
@@ -2257,8 +2257,9 @@ open_return:      ret
 
 ;
 getc:
+               stc                     ; If we exit here -> EOF
                mov ecx,[FBytes]
-               jecxz getc_end
+               jecxz getc_ret
                mov si,[FPtr]
                cmp si,[EndOfGetCBuf]
                jb getc_loaded
@@ -2281,8 +2282,8 @@ getc_oksize:      sub [FClust],cx         ; Reduce remaining clusters
 getc_loaded:   lodsb                   ; Load a byte
                mov [FPtr],si           ; Update next byte pointer
                dec dword [FBytes]      ; Update bytes left counter (CF = 1)
-getc_end:      cmc                     ; Set CF = 1 on EOF, 0 if not
-               ret
+               clc                     ; Not EOF
+getc_ret:      ret
 
 ;
 ; ungetc:      Push a character (in AL) back into the getc buffer
@@ -2386,7 +2387,7 @@ gkw_skipline:     cmp al,10               ; Scan for LF
 ;
 getint:
                mov di,NumBuf
-gi_getnum:     cmp di,[NumBufEnd]      ; Last byte in NumBuf
+gi_getnum:     cmp di,NumBufEnd        ; Last byte in NumBuf
                jae gi_loaded
                push di
                call getc

diff --git a/syslinux.asm b/syslinux.asm
index 53425c5..92163b9 100644 (file)
--- a/syslinux.asm
+++ b/syslinux.asm
@@ -130,7 +130,7 @@ got_cmdline:
                cmp word [bx+dpbSectorSize],512 ; Sector size = 512 required
                jne sectorsize_error
 
-               cmp byte [bx+dpbClusterShift],6 ; Max size = 32K = 2^6 sectors
+               cmp byte [bx+dpbClusterShift],5 ; Max size = 16K = 2^5 sectors
                jna read_bootsect
 
 hugeclust_error:
@@ -264,7 +264,7 @@ msg_error:          db 'ERROR: $'
 msg_filesystem_err:    db 'Filesystem not found on disk', 0Dh, 0Ah, '$'
 msg_fat16_err:         db 'FAT16 filesystems not supported at this time', 0Dh, 0Ah, '$'
 msg_sectorsize_err:    db 'Sector sizes other than 512 bytes not supported', 0Dh, 0Ah, '$'
-msg_hugeclust_err:     db 'Clusters larger than 32K not supported', 0Dh, 0Ah, '$'
+msg_hugeclust_err:     db 'Clusters larger than 16K not supported', 0Dh, 0Ah, '$'
 msg_read_err:          db 'Disk read failed', 0Dh, 0Ah, '$'
 msg_write_err:         db 'Disk write failed', 0Dh, 0Ah, '$'
 

diff --git a/syslinux.c b/syslinux.c
index 016d39a..0a5afcc 100644 (file)
--- a/syslinux.c
+++ b/syslinux.c
@@ -21,8 +21,12 @@
  * mount the disk.  Either that or if Linux gets an fmount() system call
  * we probably could do the mounting ourselves, and make this program
  * setuid safe.
+ *
+ * Also, sync() between accessing the raw device and mount/umount seems
+ * to be necessary; I get data corruption otherwise.
  */
 
+#include <alloca.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <mntent.h>
@@ -107,6 +111,7 @@ int main(int argc, char *argv[])
   pid_t f, w;
   int status;
   char *mntpath = NULL, mntname[64];
+  char *ldlinux_name;
   int my_umask;
 
   program = argv[0];
@@ -150,6 +155,8 @@ int main(int argc, char *argv[])
     left -= nb;
   }
   close(dev_fd);
+
+  sync();
   
   /*
    * Check to see that what we got was indeed an MS-DOS boot sector/superblock
@@ -199,8 +206,8 @@ int main(int argc, char *argv[])
            device);
     exit(1);
   }
-  if ( sectbuf[bsSecPerClust] > 64 ) {
-    fprintf(stderr, "%s: Cluster sizes larger than 32K not supported\n",
+  if ( sectbuf[bsSecPerClust] > 32 ) {
+    fprintf(stderr, "%s: Cluster sizes larger than 16K not supported\n",
            device);
   }
 
@@ -226,6 +233,7 @@ int main(int argc, char *argv[])
             !strcmp(mnt->mnt_type, "auto") ) &&
           hasmntopt(mnt, "user") &&
           !hasmntopt(mnt, "ro") &&
+          mnt->mnt_dir[0] == '/' &&
           !!hasmntopt(mnt, "loop") == !!S_ISREG(st.st_mode)) {
        /* Okay, this is an fstab entry we should be able to live with. */
 
@@ -287,15 +295,16 @@ int main(int argc, char *argv[])
     exit(1);                   /* Mount failed */
   }
 
-  if ( chdir(mntpath) ) {
-    perror("chdir");
-    if ( !euid )
-      rmdir(mntpath);
-    exit(1);
+  ldlinux_name = alloca(strlen(mntpath)+13);
+  if ( !ldlinux_name ) {
+    perror("malloc");
+    err = 1;
+    goto umount;
   }
+  sprintf(ldlinux_name, "%s/ldlinux.sys", mntpath);
 
-  unlink("ldlinux.sys");
-  fd = open("ldlinux.sys", O_WRONLY|O_CREAT|O_TRUNC, 0444);
+  unlink(ldlinux_name);
+  fd = open(ldlinux_name, O_WRONLY|O_CREAT|O_TRUNC, 0444);
   if ( fd < 0 ) {
     perror(device);
     err = 1;
@@ -329,8 +338,6 @@ int main(int argc, char *argv[])
   close(fd);
 
 umount:
-  chdir("/");
-
   f = fork();
   if ( f < 0 ) {
     perror("fork");
@@ -344,6 +351,8 @@ umount:
     exit(1);
   }
 
+  sync();
+
   if ( !euid )
     rmdir(mntpath);