From 1510f65468299c475b5f362082ac6b85f80dd692 Mon Sep 17 00:00:00 2001
From: mintsuki <mintsuki@protonmail.com>
Date: Sun, 21 Aug 2022 20:47:26 +0200
Subject: [PATCH] ZealBooter: Further cleanup and fix BIOS boot

---
 build/build-temp-vm-uefi-1.sh | 14 ++++++++++++--
 src/limine.cfg                |  1 +
 zealbooter/trampoline.S       | 11 ++++++-----
 zealbooter/zealbooter.c       | 12 ++----------
 4 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/build/build-temp-vm-uefi-1.sh b/build/build-temp-vm-uefi-1.sh
index 8515eae7..2f584970 100755
--- a/build/build-temp-vm-uefi-1.sh
+++ b/build/build-temp-vm-uefi-1.sh
@@ -51,9 +51,15 @@ rm ../src/Home/Registry.ZC 2> /dev/null
 rm ../src/Home/MakeHome.ZC 2> /dev/null
 mount_tempdisk
 sudo cp -r ../src/* $TMPMOUNT
-[ ! -d "limine" ] && git clone https://github.com/limine-bootloader/limine.git --branch=v3.0-branch-binary --depth=1
+
+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
 sudo cp limine/BOOTX64.EFI $TMPMOUNT/EFI/BOOT/BOOTX64.EFI
+sudo cp limine/limine.sys $TMPMOUNT/
 sudo cp ../zealbooter/zealbooter.elf $TMPMOUNT/Boot/ZealBooter.ELF
 umount_tempdisk
 
@@ -69,8 +75,12 @@ if [ ! -d "ovmf" ]; then
     cd ..
 fi
 
-echo "Testing..."
+./limine/limine-deploy $TMPDISK
+
+echo "Testing UEFI..."
 qemu-system-x86_64 -machine q35,accel=kvm -drive format=raw,file=$TMPDISK -m 1G -rtc base=localtime -bios ovmf/OVMF.fd -smp 4
+echo "Testing BIOS..."
+qemu-system-x86_64 -machine q35,accel=kvm -drive format=raw,file=$TMPDISK -m 1G -rtc base=localtime -smp 4
 
 echo "Deleting temp folder..."
 rm -rf $TMPDIR
diff --git a/src/limine.cfg b/src/limine.cfg
index 99be36b6..56701749 100644
--- a/src/limine.cfg
+++ b/src/limine.cfg
@@ -1,4 +1,5 @@
 TIMEOUT=2
+INTERFACE_RESOLUTION=1024x768
 
 :ZealOS
 PROTOCOL=limine
diff --git a/zealbooter/trampoline.S b/zealbooter/trampoline.S
index a02d4868..e9003450 100644
--- a/zealbooter/trampoline.S
+++ b/zealbooter/trampoline.S
@@ -2,7 +2,11 @@
 
 .global trampoline
 trampoline:
-    pushq $0x18
+    mov $0x6000, %esp
+
+    lgdt (%rcx)
+
+    pushq $0x30
     addq $(1f - trampoline), %rax
     pushq %rax
     lretq
@@ -10,15 +14,13 @@ trampoline:
     .code32
     1:
 
-    mov $0x20, %eax
+    mov $0x10, %eax
     mov %eax, %ds
     mov %eax, %es
     mov %eax, %fs
     mov %eax, %gs
     mov %eax, %ss
 
-    lgdt (%ecx)
-
     mov %cr0, %eax
     btr $31, %eax
     mov %eax, %cr0
@@ -31,7 +33,6 @@ trampoline:
     mov %ebx, %eax
     mov $2, %ebx
 
-    mov $0x7c00, %esp
     jmp *%eax
 
 .global trampoline_end
diff --git a/zealbooter/zealbooter.c b/zealbooter/zealbooter.c
index 0c1b4fce..51a5374d 100644
--- a/zealbooter/zealbooter.c
+++ b/zealbooter/zealbooter.c
@@ -203,14 +203,6 @@ void _start(void) {
     CKernel->boot_base = (uintptr_t)&CKernel->jmp - (uintptr_t)kernel->address;
     CKernel->boot_base += final_address;
 
-    CKernel->sys_gdt.boot_ds.lo = 0x00CF92000000FFFF;
-    CKernel->sys_gdt.boot_cs.lo = 0x00CF9A000000FFFF;
-    CKernel->sys_gdt.cs32.lo = 0x00CF9A000000FFFF;
-    CKernel->sys_gdt.cs64.lo = 0x00209A0000000000;
-    CKernel->sys_gdt.cs64_ring3.lo = 0x0020FA0000000000;
-    CKernel->sys_gdt.ds.lo = 0x00CF92000000FFFF;
-    CKernel->sys_gdt.ds_ring3.lo = 0x00CFF2000000FFFF;
-
     CKernel->sys_gdt_ptr.limit = sizeof(CKernel->sys_gdt) - 1;
     CKernel->sys_gdt_ptr.base = (void *)&CKernel->sys_gdt - (uintptr_t)kernel->address;
     CKernel->sys_gdt_ptr.base += final_address;
@@ -251,8 +243,8 @@ void _start(void) {
 
     void *trampoline_phys = (void *)final_address - ((uintptr_t)trampoline_end - (uintptr_t)trampoline);
 
-    memcpy(trampoline_phys, trampoline, ((uintptr_t)trampoline_end - (uintptr_t)trampoline));
-    memcpy((void *)final_address, CKernel, kernel->size);
+    memmove(trampoline_phys, trampoline, ((uintptr_t)trampoline_end - (uintptr_t)trampoline));
+    memmove((void *)final_address, CKernel, kernel->size);
 
     asm volatile (
         "jmp *%0"