Started multitasking

12 files changed, 198 insertions, 13 deletions

diff --git a/apps/Makefile b/apps/Makefile
index 574f135..56e5472 100644
--- a/apps/Makefile
+++ b/apps/Makefile
@@ -1,6 +1,6 @@
 # MIT License, Copyright (c) 2020 Marvin Borner
 
-COBJS = test.o
+COBJS = a.o b.o root.o
 CC = ../cross/opt/bin/i686-elf-gcc
 LD = ../cross/opt/bin/i686-elf-ld
 OC = ../cross/opt/bin/i686-elf-objcopy
@@ -10,7 +10,7 @@ CFLAGS = $(CSFLAGS) -Wall -Wextra -nostdlib -nostdinc -ffreestanding -ffunction-
 all: $(COBJS)
 
 %.o: %.c
-	@mkdir -p ../build/
+	@mkdir -p ../build/apps/
 	@$(CC) -c $(CFLAGS) $< -o $@
 	@$(LD) -o $(@:.o=.elf) -Tlink.ld $@
-	@$(OC) -O binary $(@:.o=.elf) ../build/$(@:.o=)
+	@$(OC) -O binary $(@:.o=.elf) ../build/apps/$(@:.o=)
diff --git a/apps/test.c b/apps/a.c
index ad84996..f09bb96 100644
--- a/apps/test.c
+++ b/apps/a.c
@@ -42,5 +42,5 @@ void serial_print(const char *data)
 
 void main()
 {
-	serial_print("Follow the white rabbit.");
+	serial_print("a");
 }
diff --git a/apps/b.c b/apps/b.c
new file mode 100644
index 0000000..3de20bf
--- /dev/null
+++ b/apps/b.c
@@ -0,0 +1,46 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#include <def.h>
+
+u32 strlen(const char *s)
+{
+	const char *ss = s;
+	while (*ss)
+		ss++;
+	return ss - s;
+}
+
+u8 inb(u16 port)
+{
+	u8 value;
+	__asm__ volatile("inb %1, %0" : "=a"(value) : "Nd"(port));
+	return value;
+}
+
+void outb(u16 port, u8 data)
+{
+	__asm__ volatile("outb %0, %1" ::"a"(data), "Nd"(port));
+}
+
+int is_transmit_empty()
+{
+	return inb(0x3f8 + 5) & 0x20;
+}
+
+void serial_put(char ch)
+{
+	while (is_transmit_empty() == 0)
+		;
+	outb(0x3f8, (u8)ch);
+}
+
+void serial_print(const char *data)
+{
+	for (u32 i = 0; i < strlen(data); i++)
+		serial_put(data[i]);
+}
+
+void main()
+{
+	serial_print("b");
+}
diff --git a/apps/root.c b/apps/root.c
new file mode 100644
index 0000000..e7cbf4e
--- /dev/null
+++ b/apps/root.c
@@ -0,0 +1,48 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#include <def.h>
+
+u32 strlen(const char *s)
+{
+	const char *ss = s;
+	while (*ss)
+		ss++;
+	return ss - s;
+}
+
+u8 inb(u16 port)
+{
+	u8 value;
+	__asm__ volatile("inb %1, %0" : "=a"(value) : "Nd"(port));
+	return value;
+}
+
+void outb(u16 port, u8 data)
+{
+	__asm__ volatile("outb %0, %1" ::"a"(data), "Nd"(port));
+}
+
+int is_transmit_empty()
+{
+	return inb(0x3f8 + 5) & 0x20;
+}
+
+void serial_put(char ch)
+{
+	while (is_transmit_empty() == 0)
+		;
+	outb(0x3f8, (u8)ch);
+}
+
+void serial_print(const char *data)
+{
+	for (u32 i = 0; i < strlen(data); i++)
+		serial_put(data[i]);
+}
+
+void main()
+{
+	serial_print("root loaded\n");
+	while (1) {
+	};
+}
diff --git a/run b/run
index 97fe9e0..cd8a023 100755
--- a/run
+++ b/run
@@ -96,7 +96,7 @@ make_build() {
     mkdir -p mnt/
     sudo mount build/disk.img mnt/
     sudo cp -r disk/* mnt/
-    sudo cp build/test mnt/
+    sudo cp build/apps/* mnt/
     cat disk/**/* >/dev/null
     sudo umount mnt/
     rm -rf mnt/
diff --git a/src/Makefile b/src/Makefile
index 37ad049..e4b11fd 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -13,6 +13,7 @@ COBJS = main.o \
 		features/psf.o \
 		features/gui.o \
 		features/load.o \
+		features/proc.o \
 		lib/str.o \
 		lib/mem.o \
 		lib/math.o \
diff --git a/src/features/load.c b/src/features/load.c
index 958acd7..2cfa546 100644
--- a/src/features/load.c
+++ b/src/features/load.c
@@ -2,15 +2,16 @@
 
 #include <def.h>
 #include <fs.h>
-#include <load.h>
+#include <mem.h>
 #include <print.h>
+#include <proc.h>
 
-void bin_load(char *path)
+void bin_load(char *path, struct proc *proc)
 {
 	char *data = read_file(path);
+	u32 stack = (u32)malloc(0x1000) + 0x1000;
 
-	void (*entry)();
-	*(void **)(&entry) = data;
-
-	entry();
+	proc->regs.ebp = stack;
+	proc->regs.esp = stack;
+	proc->regs.eip = (u32)&data;
 }
diff --git a/src/features/proc.c b/src/features/proc.c
new file mode 100644
index 0000000..92e17f1
--- /dev/null
+++ b/src/features/proc.c
@@ -0,0 +1,64 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#include <interrupts.h>
+#include <load.h>
+#include <mem.h>
+#include <print.h>
+#include <proc.h>
+#include <timer.h>
+
+u32 pid = 0;
+struct proc *root;
+struct proc *current;
+struct proc *last;
+
+void scheduler(struct regs *regs)
+{
+	printf(".");
+	memcpy(&current->regs, regs, sizeof(struct regs));
+
+	timer_handler();
+
+	if (!current->next)
+		current = root;
+	else
+		current = current->next;
+
+	while (current->state == PROC_ASLEEP)
+		if (!current->next)
+			current = root;
+		else
+			current = current->next;
+
+	memcpy(regs, &current->regs, sizeof(struct regs));
+}
+
+void proc_attach(struct proc *proc)
+{
+	if (!last->next) {
+		last->next = proc;
+	} else {
+		struct proc *save = last;
+		while (save->next)
+			save = save->next;
+		save->next = proc;
+	}
+}
+
+struct proc *proc_make()
+{
+	struct proc *proc = (struct proc *)malloc(sizeof(*proc));
+	proc->pid = pid++;
+	proc->state = PROC_RUNNING;
+	if (current)
+		proc_attach(proc);
+	last = proc;
+	return proc;
+}
+
+void proc_init()
+{
+	current = root = proc_make();
+	bin_load("/root", root);
+	irq_install_handler(0, scheduler);
+}
diff --git a/src/inc/load.h b/src/inc/load.h
index a02afc0..60fecf9 100644
--- a/src/inc/load.h
+++ b/src/inc/load.h
@@ -3,6 +3,8 @@
 #ifndef LOAD_H
 #define LOAD_H
 
-void bin_load(char *path);
+#include <proc.h>
+
+void bin_load(char *path, struct proc *proc);
 
 #endif
diff --git a/src/inc/proc.h b/src/inc/proc.h
new file mode 100644
index 0000000..dc8b9e9
--- /dev/null
+++ b/src/inc/proc.h
@@ -0,0 +1,22 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#ifndef PROC_H
+#define PROC_H
+
+#include <def.h>
+#include <interrupts.h>
+
+enum state { PROC_RUNNING, PROC_ASLEEP };
+
+struct proc {
+	u32 pid;
+	enum state state;
+	struct regs regs;
+	/* struct proc *parent; */
+	struct proc *next;
+};
+
+void proc_init();
+struct proc *proc_make();
+
+#endif
diff --git a/src/inc/timer.h b/src/inc/timer.h
index 4b2bb8c..7c4f077 100644
--- a/src/inc/timer.h
+++ b/src/inc/timer.h
@@ -6,5 +6,6 @@
 #include <def.h>
 
 void timer_install();
+void timer_handler(); // For scheduler
 
 #endif
diff --git a/src/main.c b/src/main.c
index ba390fa..0e08229 100644
--- a/src/main.c
+++ b/src/main.c
@@ -42,7 +42,7 @@ void kernel_main(struct mem_info *mem_info, struct vid_info *vid_info)
 	gui_init(FONT_PATH);
 
 	gui_term_write("Wake up, " USERNAME "...\n");
-	bin_load("/test");
+	proc_init();
 
 	while (1) {
 	};