1. change some directory structure for the build script

2. add build script and document
   see DOC/BuildVentoyFromSource.txt for detail

IPXE/README.txt

@@ -1,8 +0,0 @@
-
-========== About Source Code =============
-1. unpack ipxe_org_code/ipxe-3fe683e.tar.bz2
-2. After decompressing, delete ipxe-3fe683e/src/drivers (whole directory)
-3. Merge left source code with the ipxe-3fe683e directory here
-
-========== Build =============
-make bin/ipxe.iso 

IPXE/buildipxe.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+rm -rf ipxe-3fe683e
+
+tar -xvf ipxe_org_code/ipxe-3fe683e.tar.bz2 -C ./
+
+rm -rf ./ipxe-3fe683e/src/bin
+rm -rf ./ipxe-3fe683e/src/drivers
+
+/bin/cp -a ipxe_mod_code/ipxe-3fe683e ./
+
+cd ipxe-3fe683e/src
+
+sh build.sh
+
+cd ../../
+

IPXE/ipxe_mod_code/ipxe-3fe683e/src/arch/x86/interface/pcbios/ventoy_int13.c

@@ -1374,6 +1374,25 @@ static int int13_load_eltorito ( unsigned int drive, struct segoff *address ) {
 		return -EIO;
 	}
 
+    if (catalog.boot.length > 4)
+    {
+		isolinux_boot_info *bootinfo = NULL;
+        bootinfo = (isolinux_boot_info *)(real_to_user(address->segment, address->offset));
+        if (0x7C6CEAFA == bootinfo->isolinux0 && 0x90900000 == bootinfo->isolinux1)
+        {
+            if (bootinfo->BootFileLocation == 0 && bootinfo->PvdLocation == 16 && 
+                (bootinfo->BootFileLen / 2048) < catalog.boot.length && bootinfo->BootFileChecksum > 0)
+            {
+                if (g_debug)
+                {
+                    printf("isolinux file location is 0, now fix it to %u ...\n", catalog.boot.start);
+                    ventoy_debug_pause();
+                }
+                bootinfo->BootFileLocation = catalog.boot.start;
+            }
+        }
+    }
+
 	return 0;
 }
 

IPXE/ipxe_mod_code/ipxe-3fe683e/src/build.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+build_bios() {
+    rm -f bin/ipxe.iso
+
+    make -e -k -j 8 bin/ipxe.iso   BIOS_MODE=BIOS
+
+    if ! [ -e bin/ipxe.iso ]; then
+        echo "Failed"
+        exit 1
+    fi
+
+    mkdir -p ./mnt
+    mount bin/ipxe.iso ./mnt
+
+    rm -f ../../../INSTALL/ventoy/ipxe.krn
+    cp -a ./mnt/ipxe.krn ../../../INSTALL/ventoy/ipxe.krn        
+    
+    umount ./mnt > /dev/null 2>&1
+    umount ./mnt > /dev/null 2>&1
+    umount ./mnt > /dev/null 2>&1
+    
+    rm -rf ./mnt
+
+    echo -e "\n===============SUCCESS===============\n"
+}
+
+
+build_bios
+
+