Add boot loader ID to the memdisk info structure

diff --git a/memdisk/memdisk.asm b/memdisk/memdisk.asm
index 7acb3cb..3c33120 100644 (file)
--- a/memdisk/memdisk.asm
+++ b/memdisk/memdisk.asm
@@ -697,7 +697,7 @@ Mover_dummy2:       dd 0, 0, 0, 0           ; More space for the BIOS
 
                alignb 4, db 0
 MemDisk_Info   equ $                   ; Pointed to by installation check
-MDI_Bytes      dw 26                   ; Total bytes in MDI structure
+MDI_Bytes      dw 27                   ; Total bytes in MDI structure
 MDI_Version    db VER_MINOR, VER_MAJOR ; MEMDISK version
 
 PatchArea      equ $                   ; This gets filled in by the installer
@@ -710,7 +710,10 @@ OldInt13   dd 0                    ; INT 13h in chain
 OldInt15       dd 0                    ; INT 15h in chain
 
 OldDosMem      dw 0                    ; Old position of DOS mem end
+BootLoaderID   db 0                    ; Boot loader ID from header
 ; ---- MDI structure ends here ---
+               db 0, 0, 0              ; pad
+
 MemInt1588     dw 0                    ; 1MB-65MB memory amount (1K)
 
 Cylinders      dw 0                    ; Cylinder count

diff --git a/memdisk/memdisk.doc b/memdisk/memdisk.doc
index b67355e..91e9b3a 100644 (file)
--- a/memdisk/memdisk.doc
+++ b/memdisk/memdisk.doc
@@ -125,7 +125,7 @@ http://www.ctyme.com/rbrown.htm, for a detailed description.
 
 The MEMDISK info structure currently contains:
 
-       [ES:DI]         word    Total size of structure (currently 26 bytes)
+       [ES:DI]         word    Total size of structure (currently 27 bytes)
        [ES:DI+2]       byte    MEMDISK minor version
        [ES:DI+3]       byte    MEMDISK major version
        [ES:DI+4]       dword   Pointer to MEMDISK data in high memory
@@ -134,6 +134,10 @@ The MEMDISK info structure currently contains:
        [ES:DI+16]      16:16   Old INT 13h pointer
        [ES:DI+20]      16:16   Old INT 15h pointer
        [ES:DI+24]      word    Amount of DOS memory before MEMDISK loaded
+       [ES:DI+26]      byte    Boot loader ID
+
+MEMDISK 3.00 and higher has the size of this structure as 27; earlier
+versions had size 26 and did not include the boot loader ID.
 
 In addition, the following fields are available at [ES:0]:
 

diff --git a/memdisk/setup.c b/memdisk/setup.c
index 5275487..f0dd0f4 100644 (file)
--- a/memdisk/setup.c
+++ b/memdisk/setup.c
@@ -70,6 +70,9 @@ struct patch_area {
   uint32_t oldint15;
 
   uint16_t olddosmem;
+  uint8_t  bootloaderid;
+
+  uint8_t  _pad[3];
   uint16_t memint1588;
 
   uint16_t cylinders;
@@ -90,7 +93,7 @@ struct patch_area {
   uint16_t statusptr;
 
   dpt_t dpt;
-};
+} __attribute__((packed));
 
 /* This is the header in the boot sector/setup area */
 struct setup_header {
@@ -118,7 +121,7 @@ struct setup_header {
   uint16_t pad1;
   uint32_t cmd_line_ptr;
   uint32_t initrd_addr_max;
-};
+} __attribute__((packed));
 
 const struct setup_header * const shdr = (struct setup_header *)(LOW_SEG << 4);
 
@@ -571,8 +574,10 @@ uint32_t setup(syscall_t cs_syscall, void *cs_bounce)
   pptr->disksize  = geometry->sectors;
   pptr->diskbuf   = ramdisk_image + geometry->offset;
   pptr->statusptr = (geometry->driveno & 0x80) ? 0x474 : 0x441;
-  pptr->configflags = 0;
 
+  pptr->bootloaderid = shdr->type_of_loader;
+
+  pptr->configflags = 0;
   /* Set config flags */
   if ( getcmditem("ro") != CMD_NOTFOUND ) {
     puts("Marking disk readonly\n");