Semi-working C-based userspace syscalls

9 files changed, 47 insertions, 16 deletions

diff --git a/Makefile b/Makefile
index 0d5d541..bd3753a 100644
--- a/Makefile
+++ b/Makefile
@@ -34,13 +34,19 @@ build: clean
 	i686-elf-objcopy -O binary ./build/font.o ./build/font.bin; \
 	rm ./build/font.o; \
 
+	# Userspace
+	nasm -f elf ./src/userspace/start.asm -o ./build/user_start.o || exit; \
+	i686-elf-gcc -c ./src/userspace/main.c -o ./build/user_main.o -I ./src/mlibc -std=gnu99 -ffreestanding -O3 -Wall -Wextra -Wno-unused-parameter || exit; \
+	i686-elf-gcc -I ./src/mlibc -o ./build/user.o -std=gnu99 -ffreestanding -O2 -nostdlib ./build/user_start.o ./build/user_main.o || exit; \
+	i686-elf-objcopy -O binary ./build/user.o ./build/user.bin; \
+
 	# Create ISO
 	mkdir -p ./iso/boot/; \
 	mv ./build/melvix.bin ./iso/boot/kernel.bin; \
 	nasm ./src/bootloader/cd.asm -f bin -o ./iso/boot/cd.bin || exit; \
 	nasm ./src/bootloader/hdd1.asm -f bin -o ./iso/boot/hdd1.bin || exit; \
 	nasm ./src/bootloader/hdd2.asm -f bin -o ./iso/boot/hdd2.bin || exit; \
-	nasm ./src/userspace/main.asm -f bin -o ./iso/user.bin || exit; \
+	cp ./build/user.bin ./iso/user.bin || exit; \
 	cp ./build/font.bin ./iso/font.bin || exit; \
 	genisoimage -quiet -input-charset utf-8 -no-emul-boot -b boot/cd.bin -o ./build/melvix.iso ./iso;
 
diff --git a/src/kernel/fs/install.c b/src/kernel/fs/install.c
index 358bd98..1d8fe2e 100644
--- a/src/kernel/fs/install.c
+++ b/src/kernel/fs/install.c
@@ -78,7 +78,6 @@ void install_melvix()
     if (!font_e)
         panic("Font not found!");
     uint8_t *font = kmalloc(font_e->length + 2048);
-    serial_write_hex(font_e->length + 2048);
     ATAPI_granular_read(1 + (font_e->length / 2048), font_e->lba, font);
     marfs_new_file(font_e->length, font, 0, 0, 0);
     kfree(font);
diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index eb78257..f54eed2 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -51,8 +51,8 @@ void kernel_main()
     info("Switching to user mode...");
     syscalls_install();
     tss_flush();
-    uint32_t userspace = paging_alloc_pages(2);
-    paging_set_user(userspace, 2);
+    uint32_t userspace = paging_alloc_pages(10);
+    paging_set_user(userspace, 10);
     marfs_read_whole_file(4, (uint8_t *) (userspace + 4096));
     jump_userspace(userspace + 4096);
 
diff --git a/src/kernel/syscall/actions/sys_write.c b/src/kernel/syscall/actions/sys_write.c
index c537d12..fceaaab 100644
--- a/src/kernel/syscall/actions/sys_write.c
+++ b/src/kernel/syscall/actions/sys_write.c
@@ -1,8 +1,10 @@
 #include <stdint-gcc.h>
 #include <mlibc/stdio.h>
+#include <kernel/io/io.h>
 
 uint32_t sys_write(char *buf, uint32_t count)
 {
+    serial_write("WRITE");
     for (uint32_t i = 0; i < count; i++)
         writec(*(buf++));
     return count;
diff --git a/src/kernel/syscall/syscall.c b/src/kernel/syscall/syscall.c
index 289274b..bb32965 100644
--- a/src/kernel/syscall/syscall.c
+++ b/src/kernel/syscall/syscall.c
@@ -1,6 +1,7 @@
 #include <stdint.h>
 #include <kernel/syscall/syscall.h>
 #include <kernel/interrupts/interrupts.h>
+#include <kernel/io/io.h>
 
 void syscalls_install()
 {
@@ -10,6 +11,8 @@ void syscalls_install()
 
 uint32_t syscall_handler(uint32_t id, uint32_t arg0, uint32_t arg1, uint32_t arg2)
 {
+    serial_write("Received syscall!\n");
+
     switch (id) {
         case 1:
             return sys_write((char *) arg0, arg1);
diff --git a/src/kernel/syscall/syscall.h b/src/kernel/syscall/syscall.h
index 7fe7862..304008d 100644
--- a/src/kernel/syscall/syscall.h
+++ b/src/kernel/syscall/syscall.h
@@ -2,6 +2,7 @@
 #define MELVIX_SYSCALL_H
 
 extern void idt_syscall();
+
 void syscalls_install();
 
 uint32_t sys_write(char *buf, uint32_t count);
diff --git a/src/userspace/main.asm b/src/userspace/main.asm
deleted file mode 100644
index 4369f10..0000000
--- a/src/userspace/main.asm
+++ /dev/null
@@ -1,12 +0,0 @@
-bits 32
-mov esp, ebp
-
-mov eax, 1
-lea edi, [ebp+welcome]
-mov esi, welcome_sz
-int 0x80
-
-jmp $
-
-welcome db "Welcome to the userspace!", 0x0A, 0x0A
-welcome_sz equ $ - welcome
\ No newline at end of file
diff --git a/src/userspace/main.c b/src/userspace/main.c
new file mode 100644
index 0000000..22bb42a
--- /dev/null
+++ b/src/userspace/main.c
@@ -0,0 +1,10 @@
+#include <stddef.h>
+
+extern void syscall();
+
+void user_main()
+{
+    syscall();
+
+    while (1) {};
+}
\ No newline at end of file
diff --git a/src/userspace/start.asm b/src/userspace/start.asm
new file mode 100644
index 0000000..498f5f5
--- /dev/null
+++ b/src/userspace/start.asm
@@ -0,0 +1,22 @@
+bits 32
+section .start_section
+    dd _start
+
+section .text
+    global _start
+    extern user_main
+    _start:
+        mov esp, ebp
+        call user_main
+
+    global syscall
+    syscall:
+        mov eax, 1
+        lea edi, [ebp+welcome]
+        mov esi, welcome_sz
+        int 0x80
+        ret
+
+section .data
+        welcome db "Welcome to the userspace", 0x0A, 0x0A
+        welcome_sz equ $ - welcome
\ No newline at end of file