Merge remote branch 'origin/disklib' into disklibdev

[profile/ivi/syslinux.git] / com32 / modules / chain.c

diff --git a/com32/modules/chain.c b/com32/modules/chain.c
index cb3ee20..45e7292 100644 (file)
--- a/com32/modules/chain.c
+++ b/com32/modules/chain.c
@@ -132,6 +132,7 @@ static struct options {
     bool swap;
     bool hide;
     bool sethidden;
+    bool drmk;
 } opt;
 
 struct data_area {
@@ -786,6 +787,7 @@ Options: file=<loader>      Load and execute file, instead of boot sector\n\
          freedos=<loader>   Load FreeDOS KERNEL.SYS\n\
          msdos=<loader>     Load MS-DOS IO.SYS\n\
          pcdos=<loader>     Load PC-DOS IBMBIO.COM\n\
+         drmk=<loader>      Load DRMK DELLBIO.BIN\n\
          grub=<loader>      Load GRUB Legacy stage2\n\
          grubcfg=<filename> Set alternative config filename for GRUB Legacy\n\
          grldr=<loader>     Load GRUB4DOS grldr\n\
@@ -856,6 +858,11 @@ int main(int argc, char *argv[])
            opt.seg = 0x70;     /* MS-DOS 2.0+ wants this address */
            opt.loadfile = argv[i] + 6;
            opt.sethidden = true;
+       } else if (!strncmp(argv[i], "drmk=", 5)) {
+           opt.seg = 0x70;     /* DRMK wants this address */
+           opt.loadfile = argv[i] + 5;
+           opt.sethidden = true;
+           opt.drmk = true;
        } else if (!strncmp(argv[i], "grub=", 5)) {
            opt.seg = 0x800;    /* stage2 wants this address */
            opt.loadfile = argv[i] + 5;
@@ -1202,6 +1209,25 @@ int main(int argc, char *argv[])
            }
        }
 
+       if (opt.drmk) {
+           /* DRMK entry is different than MS-DOS/PC-DOS */
+           /*
+            * A new size, aligned to 16 bytes to ease use of ds:[bp+28].
+            * We only really need 4 new, usable bytes at the end.
+            */
+           int tsize = (data[ndata].size + 19) & 0xfffffff0;
+           regs.ss = regs.fs = regs.gs = 0;    /* Used before initialized */
+           if (!realloc(data[ndata].data, tsize)) {
+               error("Failed to realloc for DRMK\n");
+               goto bail;
+           }
+           data[ndata].size = tsize;
+           /* ds:[bp+28] must be 0x0000003f */
+           regs.ds = (tsize >> 4) + (opt.seg - 2);
+           /* "Patch" into tail of the new space */
+           *(int *)(data[ndata].data + tsize - 4) = 0x0000003f;
+       }
+
        ndata++;
     }