Fix KStart32-related issues and improvements to build script

build/build-iso.sh

@@ -36,11 +36,10 @@ umount_tempdisk() {
 
 [ ! -d $TMPMOUNT ] && mkdir -p $TMPMOUNT
 [ ! -d $TMPISODIR ] && mkdir -p $TMPISODIR
-set -e
 
+set -e
 echo "Building ZealBooter..."
 ( cd ../zealbooter && make clean all )
-
 set +e
 
 echo "Making temp vdisk, running auto-install ..."
@@ -74,18 +73,42 @@ rm ../src/Home/MakeHome.ZC 2> /dev/null
 rm ../src/Boot/Kernel.ZXE 2> /dev/null
 mount_tempdisk
 sudo cp -r ../src/* $TMPMOUNT
+umount_tempdisk
+
+echo "Building Distro ISO ..."
+qemu-system-x86_64 -machine q35,accel=kvm -drive format=raw,file=$TMPDISK -m 1G -rtc base=localtime -smp 4 -device isa-debug-exit
 
 if [ ! -d "limine" ]; then
     git clone https://github.com/limine-bootloader/limine.git --branch=v3.0-branch-binary --depth=1
     make -C limine
 fi
 
-sudo mkdir -p $TMPMOUNT/EFI/BOOT
+mount_tempdisk
-sudo cp limine/BOOTX64.EFI $TMPMOUNT/EFI/BOOT/BOOTX64.EFI
+echo "Extracting MyDistro ISO from vdisk ..."
-sudo cp limine/limine.sys $TMPMOUNT/
+cp $TMPMOUNT/Tmp/MyDistro.ISO.C ./ZealOS-MyDistro.iso
-sudo cp ../zealbooter/zealbooter.elf $TMPMOUNT/Boot/ZealBooter.ELF
+sudo rm $TMPMOUNT/Tmp/MyDistro.ISO.C 2> /dev/null
+echo "Setting up temp ISO directory contents for use with limine xorriso command ..."
+sudo cp -rf $TMPMOUNT/* $TMPISODIR
+sudo mkdir -p $TMPISODIR/EFI/BOOT
+sudo cp limine/BOOTX64.EFI $TMPISODIR/EFI/BOOT/BOOTX64.EFI
+sudo cp limine/limine-cd-efi.bin $TMPISODIR/Boot/
+sudo cp limine/limine-cd.bin $TMPISODIR/Boot/
+sudo cp limine/limine.sys $TMPISODIR/
+sudo cp ../zealbooter/zealbooter.elf $TMPISODIR/Boot/ZealBooter.ELF
+echo "Copying DVDKernel.ZXE over ISO Boot/Kernel.ZXE ..."
+sudo mv $TMPMOUNT/Tmp/DVDKernel.ZXE $TMPISODIR/Boot/Kernel.ZXE
 umount_tempdisk
 
+sudo ls $TMPISODIR -al
+
+xorriso -joliet "on" -rockridge "on" -as mkisofs -b Boot/limine-cd.bin \
+        -no-emul-boot -boot-load-size 4 -boot-info-table \
+        --efi-boot Boot/limine-cd-efi.bin \
+        -efi-boot-part --efi-boot-image --protective-msdos-label \
+        $TMPISODIR -o ZealOS-UEFI-limine-dev.iso
+
+./limine/limine-deploy ZealOS-UEFI-limine-dev.iso
+
 if [ ! -d "ovmf" ]; then
     echo "Downloading OVMF..."
     mkdir ovmf
@@ -95,38 +118,6 @@ if [ ! -d "ovmf" ]; then
     cd ..
 fi
 
-./limine/limine-deploy $TMPDISK
-
-echo "Building Distro ISO ..."
-qemu-system-x86_64 -machine q35,accel=kvm -drive format=raw,file=$TMPDISK -m 1G -rtc base=localtime -bios ovmf/OVMF.fd -smp 4 -device isa-debug-exit
-
-mount_tempdisk
-echo "Extracting MyDistro ISO from vdisk ..."
-cp $TMPMOUNT/Tmp/MyDistro.ISO.C ./ZealOS-MyDistro.iso
-sudo rm $TMPMOUNT/Tmp/MyDistro.ISO.C 2> /dev/null
-echo "Setting up temp ISO directory contents for use with limine xorriso command ..."
-sudo cp -rf $TMPMOUNT/* $TMPISODIR
-sudo cp limine/limine-cd-efi.bin $TMPISODIR/Boot/
-sudo cp limine/limine-cd.bin $TMPISODIR/Boot/
-sudo cp limine/limine.sys $TMPISODIR/
-sudo cp $TMPMOUNT/limine.cfg $TMPISODIR/limine.cfg
-sudo rm -rf $TMPISODIR/EFI
-sudo cp -rf ../zealbooter/zealbooter.elf $TMPISODIR/Boot/ZealBooter.ELF
-echo "Copying DVDKernel.ZXE over ISO Boot/Kernel.ZXE ..."
-sudo mv $TMPMOUNT/Tmp/DVDKernel.ZXE $TMPISODIR/Boot/Kernel.ZXE
-umount_tempdisk
-
-sudo ls $TMPISODIR -al
-mv $TMPDISK ./ZealOS-UEFI-limine-dev.raw
-
-xorriso -joliet "on" -rockridge "on" -as mkisofs -b Boot/limine-cd.bin \
-        -no-emul-boot -boot-load-size 4 -boot-info-table \
-        --efi-boot Boot/limine-cd-efi.bin \
-        -efi-boot-part --efi-boot-image --protective-msdos-label \
-        $TMPISODIR -o ZealOS-UEFI-limine-dev.iso
-
-./limine/limine-deploy ZealOS-UEFI-limine-dev.iso
-
 echo "Testing limine-zealbooter-xorriso isohybrid boot in UEFI mode ..."
 qemu-system-x86_64 -machine q35,accel=kvm -m 1G -rtc base=localtime -bios ovmf/OVMF.fd -smp 4 -cdrom ZealOS-UEFI-limine-dev.iso
 echo "Testing limine-zealbooter-xorriso isohybrid boot in BIOS mode ..."
@@ -138,11 +129,6 @@ qemu-system-x86_64 -machine q35,accel=kvm -m 1G -rtc base=localtime -smp 4 -cdro
 rm ./ZealOS-2*.iso 2> /dev/null # comment this line if you want lingering old Distro ISOs
 mv ./ZealOS-MyDistro.iso ./ZealOS-$(date +%Y-%m-%d-%H_%M_%S).iso
 
-echo "Testing temp vdisk in UEFI mode ..."
-qemu-system-x86_64 -machine q35,accel=kvm -drive format=raw,file=ZealOS-UEFI-limine-dev.raw -m 1G -rtc base=localtime -bios ovmf/OVMF.fd -smp 4
-echo "Testing temp vdisk in BIOS mode ..."
-qemu-system-x86_64 -machine q35,accel=kvm -drive format=raw,file=ZealOS-UEFI-limine-dev.raw -m 1G -rtc base=localtime -smp 4
-
 echo "Deleting temp folder ..."
 sudo rm -rf $TMPDIR
 sudo rm -rf $TMPISODIR

src/Kernel/KStart32.ZC

@@ -77,10 +77,6 @@ SYS_SEMAS::				DU8 	SEMA_SEMAS_NUM * DEFAULT_CACHE_LINE_WIDTH DUP(0);
 //************************************
 		ALIGN 	16, OC_NOP
 
-        // Signature to find CORE0_32BIT_INIT
-        DU64 0xaa23c08ed10bd4d7;
-        DU64 0xf6ceba7d4b74179a;
-
 CORE0_32BIT_INIT:: //Entry point for $LK,"BootRAM",A="MN:BootRAM"$.
 		PUSH	U32 RFLAGG_START
 		POPFD
@@ -89,8 +85,9 @@ CORE0_32BIT_INIT:: //Entry point for $LK,"BootRAM",A="MN:BootRAM"$.
 
 		MOV		AX,  CGDT.boot_ds //LOAD DS SELECTOR
 		MOV 	DS,  AX
-		//MOV 	ESI, U32 [SYS_BOOT_PATCH_TABLE_BASE]
+		BTS 	U32 [SYS_RUN_LEVEL], RLf_32BIT
-		//MOV 	EDI, U32 [MEM_BOOT_BASE]
+		MOV 	ESI, U32 [SYS_BOOT_PATCH_TABLE_BASE]
+		MOV 	EDI, U32 [MEM_BOOT_BASE]
 
 		MOV		AX, CGDT.ds
 		MOV		DS,  AX
@@ -98,8 +95,16 @@ CORE0_32BIT_INIT:: //Entry point for $LK,"BootRAM",A="MN:BootRAM"$.
 		MOV		FS,  AX
 		MOV		GS,  AX
 		MOV		SS,  AX
-		//MOV		ESP, BOOT_RAM_LIMIT //Tmp Stack
+		MOV		ESP, BOOT_RAM_LIMIT //Tmp Stack
 
+        JMP @@02
+
+        ALIGN 16, OC_NOP
+        // Signature to find CORE0_32BIT_INIT
+        DU64 0xaa23c08ed10bd4d7;
+        DU64 0xf6ceba7d4b74179a;
+
+@@02:
 //Patch abs addresses
 		MOV		ECX, U32 CPatchTableAbsAddr.abs_address_count[ESI]
 		LEA		ESI, U32 CPatchTableAbsAddr.abs_address[ESI]
@@ -113,7 +118,6 @@ CORE0_32BIT_INIT:: //Entry point for $LK,"BootRAM",A="MN:BootRAM"$.
 		DU16	CGDT.cs32;
 
 @@10: 	BTS		U32 [SYS_RUN_LEVEL], RLf_PATCHED
-		BTS 	U32 [SYS_RUN_LEVEL], RLf_32BIT
 
 		CALL	SYS_FIND_PCIBIOS_SERVICE_DIR
 		CALL	SYS_FIND_PCI_SERVICES

zealbooter/trampoline.S

@@ -2,8 +2,14 @@
 
 .global trampoline
 trampoline:
+    // Set new stack
+    mov %rdx, %rsp
+
+    // Load GDTR
     lgdt (%rcx)
 
+    // Far jump to 32-bit compatibility mode
+    // AKA (set CS to CGDT.cs32)
     pushq $0x30
     addq $(1f - trampoline), %rax
     pushq %rax
@@ -12,6 +18,7 @@ trampoline:
     .code32
     1:
 
+    // Set all data segments to CGDT.ds
     mov $0x10, %eax
     mov %eax, %ds
     mov %eax, %es
@@ -19,19 +26,26 @@ trampoline:
     mov %eax, %gs
     mov %eax, %ss
 
+    // Disable paging
     mov %cr0, %eax
     btr $31, %eax
     mov %eax, %cr0
 
+    // Disable LME and friends
     mov $0xc0000080, %ecx
     xor %eax, %eax
     xor %edx, %edx
     wrmsr
 
-    mov %ebx, %eax
+    // Set CR0 to (PE | NE) AKA SYS_START_CR0
-    mov $2, %ebx
+    mov $0x11, %eax
+    mov %eax, %cr0
 
-    jmp *%eax
+    // Set flags to 0x02
+    pushl $0x02
+    popfl
+
+    jmp *%ebx
 
 .global trampoline_end
 trampoline_end:

zealbooter/zealbooter.c

@@ -116,8 +116,9 @@ struct CKernel {
 #define BOOT_SRC_RAM 2
 #define BOOT_SRC_HDD 3
 #define BOOT_SRC_DVD 4
-#define RLF_16BIT 0b01
+#define RLF_16BIT 0b001
-#define RLF_VESA  0b10
+#define RLF_VESA  0b010
+#define RLF_32BIT 0b100
 
 extern symbol trampoline, trampoline_end;
 
@@ -210,7 +211,7 @@ void _start(void) {
     CKernel->boot_patch_table_base -= (uintptr_t)kernel->address;
     CKernel->boot_patch_table_base += final_address;
 
-    CKernel->sys_run_level = RLF_VESA | RLF_16BIT;
+    CKernel->sys_run_level = RLF_VESA | RLF_16BIT | RLF_32BIT;
 
     CKernel->boot_base = (uintptr_t)&CKernel->jmp - (uintptr_t)kernel->address;
     CKernel->boot_base += final_address;
@@ -269,12 +270,11 @@ void _start(void) {
     memcpy((void *)final_address, CKernel, kernel->size);
 
     asm volatile (
-        "mov %5, %%rsp;"
         "jmp *%0"
         :
         : "a"(trampoline_phys), "b"(CORE0_32BIT_INIT),
-          "c"(sys_gdt_ptr), "S"(CKernel->boot_patch_table_base),
+          "c"(sys_gdt_ptr), "d"(boot_stack),
-          "D"(CKernel->boot_base), "r"(boot_stack)
+          "S"(CKernel->boot_patch_table_base), "D"(CKernel->boot_base)
         : "memory");
 
     __builtin_unreachable();