Prepare system calls

kernel/Makefile

@@ -13,7 +13,7 @@ KERNEL_D_FILES=$(KERNEL_CPP_FILES:%.cpp=%.cpp.d)
 KERNEL_D_STL_FILES=$(KERNEL_CPP_STL_FILES:%.cpp=%.cpp.d)
 
 #TODO Generate also the o files coming from s files automatically, ignoring crti and crtn
-KERNEL_O_FILES=boot_16_64.o boot_32_64.o $(KERNEL_CPP_FILES:%.cpp=%.cpp.o) $(KERNEL_CPP_STL_FILES:%.cpp=%.cpp.o) isrs.s.o irqs.s.o arch.s.o
+KERNEL_O_FILES=boot_16_64.o boot_32_64.o $(KERNEL_CPP_FILES:%.cpp=%.cpp.o) $(KERNEL_CPP_STL_FILES:%.cpp=%.cpp.o) isrs.s.o irqs.s.o arch.s.o syscalls.s.o
 
 CRTBEGIN_OBJ:=$(shell $(CC) $(CFLAGS) -print-file-name=crtbegin.o)
 CRTEND_OBJ:=$(shell $(CC) $(CFLAGS) -print-file-name=crtend.o)

kernel/include/interrupts.hpp

@@ -12,6 +12,9 @@
 
 namespace interrupt {
 
+constexpr const size_t SYSCALL_FIRST = 50;
+constexpr const size_t SYSCALL_MAX = 10;
+
 struct fault_regs {
     uint64_t error_no;
     uint64_t error_code;
@@ -22,9 +25,20 @@ struct fault_regs {
     uint64_t ss;
 } __attribute__((packed));
 
+struct syscall_regs {
+    uint64_t rax;
+    uint64_t rbx;
+    uint64_t rcx;
+    uint64_t rdx;
+    uint64_t rsi;
+    uint64_t rdi;
+} __attribute__((packed));
+
 void setup_interrupts();
 
 void register_irq_handler(size_t irq, void (*handler)());
+void register_syscall_handler(size_t irq, void (*handler)(const syscall_regs&));
+
 
 } //end of interrupt namespace
 

kernel/include/syscalls.hpp

@@ -0,0 +1,26 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#ifndef SYSCALLS_H
+#define SYSCALLS_H
+
+extern "C" {
+
+void _syscall0();
+void _syscall1();
+void _syscall2();
+void _syscall3();
+void _syscall4();
+void _syscall5();
+void _syscall6();
+void _syscall7();
+void _syscall8();
+void _syscall9();
+
+} //end of extern "C"
+
+#endif

kernel/include/system_calls.hpp

@@ -0,0 +1,13 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#ifndef ATA_H
+#define ATA_H
+
+void system_call_entry();
+
+#endif

kernel/src/interrupts.cpp

@@ -12,6 +12,7 @@
 
 #include "isrs.hpp"
 #include "irqs.hpp"
+#include "syscalls.hpp"
 
 #include "stl/types.hpp"
 
@@ -151,6 +152,20 @@ void install_irqs(){
     idt_set_gate(47, _irq15, gdt::LONG_SELECTOR, 0x8E);
 }
 
+void install_syscalls(){
+    idt_set_gate(interrupt::SYSCALL_FIRST, _syscall0, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+1, _syscall1, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+2, _syscall2, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+3, _syscall3, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+4, _syscall4, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+5, _syscall5, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+6, _syscall6, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+7, _syscall7, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+8, _syscall8, gdt::LONG_SELECTOR, 0x8E);
+    idt_set_gate(interrupt::SYSCALL_FIRST+9, _syscall9, gdt::LONG_SELECTOR, 0x8E);
+
+}
+
 void enable_interrupts(){
     __asm__ __volatile__("sti" : : );
 }
@@ -205,7 +220,6 @@ void _fault_handler(interrupt::fault_regs regs){
     k_printf("cr2=%h\n", get_cr2());
 
     //TODO Improve that with kind of blue screen
-    //TODO Display the title of the exception
 
     __asm__ __volatile__("hlt" : : );
 }
@@ -225,6 +239,11 @@ void _irq_handler(size_t code){
     out_byte(0x20, 0x20);
 }
 
+void _syscall_handler(interrupt::syscall_regs regs){
+    //TODO Call handler if any
+    //TODO Otherwise, display error
+}
+
 } //end of extern "C"
 
 void interrupt::register_irq_handler(size_t irq, void (*handler)()){
@@ -236,5 +255,6 @@ void interrupt::setup_interrupts(){
     install_isrs();
     remap_irqs();
     install_irqs();
+    install_syscalls();
     enable_interrupts();
 }

kernel/src/syscalls.s

@@ -0,0 +1,137 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+.intel_syntax noprefix
+
+// Define the base ISRs
+
+.global _syscall0
+.global _syscall0
+.global _syscall1
+.global _syscall2
+.global _syscall3
+.global _syscall4
+.global _syscall5
+.global _syscall6
+.global _syscall7
+.global _syscall8
+.global _syscall9
+
+_syscall0:
+    cli
+
+    push rdi
+    mov rdi, 0
+
+    jmp syscall_common_handler
+
+_syscall1:
+    cli
+
+    push rdi
+    mov rdi, 1
+
+    jmp syscall_common_handler
+
+_syscall2:
+    cli
+
+    push rdi
+    mov rdi, 2
+
+    jmp syscall_common_handler
+
+_syscall3:
+    cli
+
+    push rdi
+    mov rdi, 3
+
+    jmp syscall_common_handler
+
+_syscall4:
+    cli
+
+    push rdi
+    mov rdi, 4
+
+    jmp syscall_common_handler
+
+_syscall5:
+    cli
+
+    push rdi
+    mov rdi, 5
+
+    jmp syscall_common_handler
+
+_syscall6:
+    cli
+
+    push rdi
+    mov rdi, 6
+
+    jmp syscall_common_handler
+
+_syscall7:
+    cli
+
+    push rdi
+    mov rdi, 7
+
+    jmp syscall_common_handler
+
+_syscall8:
+    cli
+
+    push rdi
+    mov rdi, 8
+
+    jmp syscall_common_handler
+
+_syscall9:
+    cli
+
+    push rdi
+    mov rdi, 9
+
+    jmp syscall_common_handler
+
+// Common handler
+
+//TODO Check if really safe to trash r12
+syscall_common_handler:
+    push r8
+    push r9
+    push r10
+    push r11
+    push r12
+    push rax
+    push rbx
+    push rcx
+    push rdx
+    push rsi
+    push rdi
+
+    call _syscall_handler
+
+    pop rdi
+    pop rsi
+    pop rdx
+    pop rcx
+    pop rbx
+    pop rax
+    pop r12
+    pop r11
+    pop r10
+    pop r9
+    pop r8
+
+    //Was pushed by the base handler code
+    pop rdi
+
+    iretq // iret will clean the other automatically pushed stuff