arch: i386: add a spinlock implementation

Add two functions to control thread-local spinlocks.

Signed-off-by: Danny Holman <dholman@gymli.org>

5 files changed, 131 insertions, 10 deletions

diff --git a/arch/i386/include/kernel/asm.h b/arch/i386/include/kernel/asm.h
index cf394e1..3c7bc00 100644
--- a/arch/i386/include/kernel/asm.h
+++ b/arch/i386/include/kernel/asm.h
@@ -1,6 +1,7 @@
 #ifndef I386_ASM_H
 #define I386_ASM_H
 
+#include <kernel/gdt.h>
 #include <stdint.h>
 
 extern uintptr_t _kernel_start;
@@ -8,19 +9,30 @@ extern uintptr_t _kernel_end;
 #define KSTART          ((uintptr_t)&_kernel_start)
 #define KEND            ((uintptr_t)&_kernel_end - 0xC0000000)
 
-#define HIMEM_START     0x00100000
 #define PAGE_SIZE       4096
 
-struct thread_block {
+#define PCI_CONFIG_ADDR 0xCF8
+#define PCI_CONFIG_DATA 0xCFC
+
+#define COM_PORT        0x3F8
+
+struct regs {
+        uint32_t eax;
+        uint32_t ebx;
+        uint32_t ecx;
+        uint32_t edx;
+        uint32_t esi;
+        uint32_t edi;
+        uint32_t ebp;
         uint32_t esp;
+
+        uint32_t cr0;
+        uint32_t cr2;
         uint32_t cr3;
-        unsigned int tid;
-        unsigned int tgid;
-        unsigned int state;
-        struct thread_block *next;
+        uint32_t cr4;
 };
 
-struct regs {
+struct isr_frame {
         uint32_t cr4;
         uint32_t cr3;
         uint32_t cr2;
@@ -92,16 +104,41 @@ void irq_stub_15(void);
 
 void syscall_stub(void);
 
+void aquire_lock(int *lock);
+void release_lock(int *lock);
+
+void enable_paging(uint32_t new_cr3);
+
 static inline void outb(uint16_t port, uint8_t value) {
         __asm__ volatile("outb %0, %1" : : "a"(value), "Nd"(port));
 }
 
+static inline void outw(uint16_t port, uint16_t value) {
+        __asm__ volatile("outw %0, %1" : : "a"(value), "Nd"(port));
+}
+
+static inline void outl(uint16_t port, uint32_t value) {
+        __asm__ volatile("outl %0, %1" : : "a"(value), "Nd"(port));
+}
+
 static inline uint8_t inb(uint16_t port) {
         uint8_t ret;
         __asm__ volatile("inb %1, %0" : "=a"(ret) : "Nd"(port));
         return ret;
 }
 
+static inline uint16_t inw(uint16_t port) {
+        uint16_t ret;
+        __asm__ volatile("inw %1, %0" : "=a"(ret) : "Nd"(port));
+        return ret;
+}
+
+static inline uint32_t inl(uint16_t port) {
+        uint32_t ret;
+        __asm__ volatile("inl %1, %0" : "=a"(ret) : "Nd"(port));
+        return ret;
+}
+
 static inline void enable_ints(void) {
         __asm__ volatile("sti");
 }
diff --git a/arch/i386/kernel/spinlock.s b/arch/i386/kernel/spinlock.s
new file mode 100644
index 0000000..c8235ca
--- /dev/null
+++ b/arch/i386/kernel/spinlock.s
@@ -0,0 +1,30 @@
+.section .text
+
+.global aquire_lock
+.type aquire_lock, @function
+aquire_lock:
+        pushl %ebp
+        movl %esp, %ebp
+locked:
+        movl 8(%esp), %eax
+        lock incl (%eax)
+        jc spin_wait
+
+        popl %ebp
+        ret
+spin_wait:
+        test %eax, 1
+        jnz spin_wait
+        jmp locked
+
+.global release_lock
+.type release_lock, @function
+release_lock:
+        pushl %ebp
+        movl %esp, %ebp
+
+        movl 8(%ebp), %eax
+        lock decl (%eax)
+
+        popl %ebp
+        ret
diff --git a/arch/i386/make.config b/arch/i386/make.config
index d4d98a7..82d0733 100644
--- a/arch/i386/make.config
+++ b/arch/i386/make.config
@@ -7,15 +7,13 @@ KERNEL_ARCH_OBJS=$(ARCHDIR)/boot/boot.o \
                  $(ARCHDIR)/kernel/idt.o \
                  $(ARCHDIR)/kernel/gdt.o \
                  $(ARCHDIR)/kernel/isr.o \
-                 $(ARCHDIR)/kernel/framebuffer.o \
                  $(ARCHDIR)/kernel/multiboot.o \
-                 $(ARCHDIR)/kernel/keyboard.o \
                  $(ARCHDIR)/kernel/serial.o \
                  $(ARCHDIR)/kernel/pic.o \
                  $(ARCHDIR)/kernel/timer.o \
+                 $(ARCHDIR)/kernel/spinlock.o \
                  $(ARCHDIR)/kernel/syscall.o \
                  $(ARCHDIR)/kernel/paging.o \
                  $(ARCHDIR)/kernel/pmem.o \
                  $(ARCHDIR)/kernel/kmalloc.o \
-                 $(ARCHDIR)/kernel/jump_userspace.o \
                  $(ARCHDIR)/kernel/switch_thread.o \
diff --git a/include/kernel/video/framebuffer.h b/include/kernel/video/framebuffer.h
new file mode 100644
index 0000000..500e71b
--- /dev/null
+++ b/include/kernel/video/framebuffer.h
@@ -0,0 +1,23 @@
+#ifndef KERNEL_FRAMEBUFFER_H
+#define KERNEL_FRAMEBUFFER_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define VGA_WIDTH       80
+#define VGA_HEIGHT      25
+
+static uint16_t *const VGA_MEMORY = (uint16_t*)0xC03FF000;
+
+void fb_init(void);
+void fb_setcolor(uint8_t color);
+void fb_putchar(char c);
+void fb_setpos(int x, int y);
+void fb_offsetpos(int dx, int dy);
+
+static inline void fb_write(const char *data, size_t size) {
+        for (size_t i = 0; i < size; i++)
+                fb_putchar(data[i]);
+}
+
+#endif
diff --git a/include/kernel/video/vga.h b/include/kernel/video/vga.h
new file mode 100644
index 0000000..b639a3c
--- /dev/null
+++ b/include/kernel/video/vga.h
@@ -0,0 +1,33 @@
+#ifndef KERNEL_VGA_H
+#define KERNEL_VGA_H
+
+#include <stdint.h>
+
+enum vga_color {
+        VGA_COLOR_BLACK = 0,
+        VGA_COLOR_BLUE = 1,
+        VGA_COLOR_GREEN = 2,
+        VGA_COLOR_CYAN = 3,
+        VGA_COLOR_RED = 4,
+        VGA_COLOR_MAGENTA = 5,
+        VGA_COLOR_BROWN = 6,
+        VGA_COLOR_LIGHT_GREY = 7,
+        VGA_COLOR_DARK_GREY = 8,
+        VGA_COLOR_LIGHT_BLUE = 9,
+        VGA_COLOR_LIGHT_GREEN = 10,
+        VGA_COLOR_LIGHT_CYAN = 11,
+        VGA_COLOR_LIGHT_RED = 12,
+        VGA_COLOR_LIGHT_MAGENTA = 13,
+        VGA_COLOR_LIGHT_BROWN = 14,
+        VGA_COLOR_LIGHT_WHITE = 15,
+};
+
+static inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg) {
+        return fg | bg << 4;
+}
+
+static inline uint16_t vga_entry(unsigned char uc, uint8_t color) {
+        return (uint16_t)uc | (uint16_t)color << 8;
+}
+
+#endif