Much work on the ELF parser and userspace jumping

13 files changed, 93 insertions, 142 deletions

diff --git a/src/kernel/fs/elf.c b/src/kernel/fs/elf.c
index 7b95c3b..f6cdecb 100644
--- a/src/kernel/fs/elf.c
+++ b/src/kernel/fs/elf.c
@@ -34,7 +34,6 @@ struct process *elf_load(char *path)
 	}
 
 	struct elf_header *header = (struct elf_header *)file;
-	struct elf_program_header *program_header = (void *)header + header->phoff;
 
 	if (!is_elf(header)) {
 		warn("File not valid: %s", path);
@@ -44,35 +43,46 @@ struct process *elf_load(char *path)
 	}
 
 	struct process *proc = process_make_new();
-	strcpy(proc->name, path);
-	proc->registers.eip = header->entry;
+	paging_switch_dir(proc->cr3);
 
-	//paging_switch_directory(proc->cr3);
-	u32 stk = (u32)valloc(PAGE_SIZE);
+	u32 image_low = 0xFFFFFFFF;
+	u32 image_high = 0;
 
-	proc->registers.useresp = 0x40000000 - (PAGE_SIZE / 2);
-	proc->registers.ebp = proc->registers.useresp;
-	proc->registers.esp = proc->registers.useresp;
-	//paging_map_user(stk, 0x40000000 - PAGE_SIZE);
+	// Parse ELF
+	for (u32 i = 0; i < header->shentsize * header->shnum; i += header->shentsize) {
+		struct elf_section_header *sh = (void *)header + (header->shoff + i);
+		if (sh->addr != 0) {
+			log("%x", sh->addr);
+			for (u32 j = 0; j < sh->size; j += PAGE_SIZE) {
+				paging_frame_alloc(paging_get_page(sh->addr + j, proc->cr3));
+				invlpg(sh->addr + j);
+				j += PAGE_SIZE;
+			}
 
-	for (int i = 0; i < header->phnum; i++, program_header++) {
-		switch (program_header->type) {
-		case 0:
-			break;
-		case 1: {
-			u32 loc = (u32)valloc(PAGE_SIZE);
-			//paging_map_user(loc, program_header->vaddr);
-			memcpy((void *)program_header->vaddr,
-			       ((void *)((u32)file) + program_header->offset),
-			       program_header->filesz);
-			assert(program_header->filesz <= PAGE_SIZE);
-			break;
-		}
-		default:
-			warn("Unknown header type");
+			if (sh->type == 8) // Is .bss
+				memset(sh->addr, 0, sh->size);
+			else
+				memcpy(sh->addr, header + sh->offset, sh->size);
+
+			if (sh->addr < image_low)
+				image_low = sh->addr;
+
+			if (sh->addr + sh->size > image_high)
+				image_high = sh->addr + sh->size;
 		}
 	}
 
-	/* paging_switch_directory(page_tables); */
+	// Stack
+	struct page_table_entry *stack_page = paging_get_page(0x400000, proc->cr3);
+	paging_frame_alloc(stack_page);
+	stack_page->writable = 1;
+	invlpg(0x400000);
+
+	strcpy(proc->name, path);
+	proc->brk = image_high;
+	proc->regs.eip = header->entry;
+	proc->regs.esp = 0x401000;
+	proc->regs.useresp = 0x401000;
+
 	return proc;
 }
\ No newline at end of file
diff --git a/src/kernel/interrupts/isr.c b/src/kernel/interrupts/isr.c
index 73e24a3..ae72a0f 100644
--- a/src/kernel/interrupts/isr.c
+++ b/src/kernel/interrupts/isr.c
@@ -128,7 +128,7 @@ void fault_handler(struct regs *r)
 		if (current_proc != NULL) {
 			warn("%s: Suspending process %s with ID %d", message, current_proc->name,
 			     current_proc->pid);
-			memcpy(&current_proc->registers, r, sizeof(struct regs));
+			memcpy(&current_proc->regs, r, sizeof(struct regs));
 			process_suspend(current_proc->pid);
 			process_force_switch();
 		} else {
diff --git a/src/kernel/io/io.c b/src/kernel/io/io.c
index af5f008..1ef82b6 100644
--- a/src/kernel/io/io.c
+++ b/src/kernel/io/io.c
@@ -98,6 +98,11 @@ void cr0_set(u32 cr0)
 	asm volatile("movl %%eax, %%cr0" ::"a"(cr0));
 }
 
+void invlpg(u32 addr)
+{
+	asm volatile("invlpg (%0)" ::"r"(addr) : "memory");
+}
+
 void serial_install()
 {
 	outb(0x3f8 + 1, 0x00);
diff --git a/src/kernel/io/io.h b/src/kernel/io/io.h
index ce3c72b..9274dfb 100644
--- a/src/kernel/io/io.h
+++ b/src/kernel/io/io.h
@@ -55,6 +55,7 @@ u32 cr3_get();
 void cr3_set(u32 cr3);
 u32 cr0_get();
 void cr0_set(u32 cr0);
+void invlpg(u32 addr);
 
 /**
  * Initialize the serial conenction
diff --git a/src/kernel/memory/paging.c b/src/kernel/memory/paging.c
index 1d9f6b1..e2c48b8 100644
--- a/src/kernel/memory/paging.c
+++ b/src/kernel/memory/paging.c
@@ -1,5 +1,6 @@
 #include <io/io.h>
 #include <lib/lib.h>
+#include <memory/alloc.h>
 #include <memory/mmap.h>
 #include <memory/paging.h>
 #include <stdint.h>
@@ -27,9 +28,16 @@ void paging_install()
 	kernel_page_directory->entries[0].writable = 1;
 	kernel_page_directory->entries[0].address = SHIFT((u32)page_table);
 
-	paging_switch_directory((u32)kernel_page_directory);
+	paging_switch_dir((u32)kernel_page_directory);
 	paging_enable();
 	info("Installed paging");
+
+	// Test mallocing
+	u32 *c = malloc(2048);
+	c[42] = 0x4242;
+	assert(c[42] == 0x4242);
+	free(c);
+	info("Malloc test succeeded!");
 }
 
 void paging_disable()
@@ -48,7 +56,7 @@ void paging_enable()
 	paging_enabled = 1;
 }
 
-void paging_switch_directory(u32 dir)
+void paging_switch_dir(u32 dir)
 {
 	cr3_set(dir);
 }
diff --git a/src/kernel/memory/paging.h b/src/kernel/memory/paging.h
index ac0dbfa..af7d4a2 100644
--- a/src/kernel/memory/paging.h
+++ b/src/kernel/memory/paging.h
@@ -49,7 +49,7 @@ struct page_dir {
 void paging_install();
 void paging_enable();
 void paging_disable();
-void paging_switch_directory(u32 dir);
+void paging_switch_dir(u32 dir);
 
 struct page_table_entry *paging_get_page(u32 address, struct page_dir *page_dir);
 void paging_frame_alloc(struct page_table_entry *page);
diff --git a/src/kernel/syscall/actions/sys_wait.c b/src/kernel/syscall/actions/sys_wait.c
index 01deef3..23d4639 100644
--- a/src/kernel/syscall/actions/sys_wait.c
+++ b/src/kernel/syscall/actions/sys_wait.c
@@ -4,7 +4,7 @@
 
 u32 sys_wait(u32 pid, u32 *status, u32 options)
 {
-	if (pid > 0)
-		return process_wait_pid(pid, status);
+	/* if (pid > 0) */
+	/* 	return process_wait_pid(pid, status); */
 	return -1;
 }
\ No newline at end of file
diff --git a/src/kernel/tasks/process.c b/src/kernel/tasks/process.c
index 0b13b6b..a4c1c79 100644
--- a/src/kernel/tasks/process.c
+++ b/src/kernel/tasks/process.c
@@ -8,7 +8,6 @@
 #include <stdint.h>
 #include <system.h>
 #include <tasks/process.h>
-#include <tasks/userspace.h>
 #include <timer/timer.h>
 
 u32 pid = 0;
@@ -36,7 +35,7 @@ void scheduler(struct regs *regs)
 	}
 
 	serial_put('+');
-	memcpy(&current_proc->registers, regs, sizeof(struct regs));
+	memcpy(&current_proc->regs, regs, sizeof(struct regs));
 
 	timer_handler(regs);
 
@@ -55,10 +54,18 @@ void scheduler(struct regs *regs)
 		}
 	}
 
-	memcpy(regs, &current_proc->registers, sizeof(struct regs));
-	paging_switch_directory(current_proc->cr3);
+	memcpy(regs, &current_proc->regs, sizeof(struct regs));
+	paging_switch_dir(current_proc->cr3);
+	if (regs->cs != 0x1B) {
+		regs->gs = 0x23;
+		regs->fs = 0x23;
+		regs->es = 0x23;
+		regs->ds = 0x23;
+		regs->cs = 0x1B;
+		regs->ss = 0x23;
+	}
+
 	locked = 0;
-	cli();
 }
 
 void process_force_switch()
@@ -68,6 +75,9 @@ void process_force_switch()
 	//scheduler(regs);
 }
 
+u32 hl_cr3;
+u32 hl_eip;
+u32 hl_esp;
 void process_init(struct process *proc)
 {
 	log("Initializing process %d", pid);
@@ -78,7 +88,15 @@ void process_init(struct process *proc)
 
 	current_proc = root;
 	irq_install_handler(0, scheduler);
-	userspace_enter(proc);
+
+	hl_eip = proc->regs.eip;
+	hl_esp = proc->regs.esp;
+	//paging_switch_dir(proc->cr3);
+
+	debug("Jumping to userspace!");
+	extern void userspace_jump();
+	userspace_jump();
+	panic("This should not happen!");
 }
 
 // Only for debugging purposes
@@ -113,25 +131,6 @@ u32 process_spawn(struct process *process)
 	return process->pid;
 }
 
-u32 process_wait_pid(u32 pid, u32 *status)
-{
-	struct process *i = current_proc->next;
-
-	while (i != NULL) {
-		if (i->pid == pid) {
-			if (i->state == PROC_ASLEEP) {
-				*status = i->registers.ebx;
-				return i->pid;
-			} else {
-				return WAIT_OKAY;
-			}
-		}
-		i = i->next;
-	}
-
-	return WAIT_ERROR;
-}
-
 void process_suspend(u32 pid)
 {
 	debug("Suspending process %d", pid);
@@ -175,15 +174,20 @@ struct process *process_from_pid(u32 pid)
 	return PID_NOT_FOUND;
 }
 
+void no_entry()
+{
+	panic("No entry point given!");
+}
+
 struct process *process_make_new()
 {
 	debug("Making new process %d", pid);
 	struct process *proc = (struct process *)valloc(sizeof(struct process));
-	proc->registers.cs = 0x1B;
-	proc->registers.ds = 0x23;
-	proc->registers.ss = 0x23;
+	proc->regs.cs = 0x1B;
+	proc->regs.ds = 0x23;
+	proc->regs.ss = 0x23;
+	proc->regs.eip = no_entry;
 	proc->cr3 = paging_make_dir();
-	proc->brk = 0x50000000;
 	proc->pid = pid++;
 	return proc;
 }
diff --git a/src/kernel/tasks/process.h b/src/kernel/tasks/process.h
index 5c72e64..493dbe5 100644
--- a/src/kernel/tasks/process.h
+++ b/src/kernel/tasks/process.h
@@ -14,7 +14,7 @@ struct mmap {
 
 struct process {
 	u32 cr3;
-	struct regs registers;
+	struct regs regs;
 
 	u32 pid;
 	char name[256];
@@ -35,9 +35,6 @@ u32 process_spawn(struct process *process);
 void process_suspend(u32 pid);
 void process_wake(u32 pid);
 
-u32 process_wait_gid(u32 gid, u32 *status);
-u32 process_wait_pid(u32 pid, u32 *status);
-
 struct process *process_from_pid(u32 pid);
 
 void process_init(struct process *proc);
diff --git a/src/kernel/tasks/userspace.asm b/src/kernel/tasks/userspace.asm
index ebdcf26..6881bdf 100644
--- a/src/kernel/tasks/userspace.asm
+++ b/src/kernel/tasks/userspace.asm
@@ -1,9 +1,9 @@
-global jump_userspace
+global userspace_jump
 extern hl_cr3
 extern hl_esp
 extern hl_eip
 
-jump_userspace:
+userspace_jump:
 	mov ax, 0x23
 	mov ds, ax
 	mov es, ax
diff --git a/src/kernel/tasks/userspace.c b/src/kernel/tasks/userspace.c
deleted file mode 100644
index 3164965..0000000
--- a/src/kernel/tasks/userspace.c
+++ /dev/null
@@ -1,59 +0,0 @@
-#include <interrupts/interrupts.h>
-#include <io/io.h>
-#include <lib/lib.h>
-#include <memory/paging.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <system.h>
-#include <tasks/process.h>
-#include <tasks/userspace.h>
-
-struct process *proc_bottom = NULL;
-
-u32 hl_cr3;
-u32 hl_eip;
-u32 hl_esp;
-
-u32 spawn_child(struct process *child)
-{
-	return (u32)-1;
-}
-
-void userspace_enter(struct process *proc)
-{
-	proc_bottom = proc;
-	hl_eip = proc->registers.eip;
-	hl_esp = proc->registers.esp;
-	paging_switch_directory(proc->cr3);
-
-	//debug("Jumping to userspace!");
-	jump_userspace();
-}
-
-void single_yield(struct process *proc, struct regs *regs)
-{
-	memcpy(&proc_bottom->registers, regs, sizeof(struct regs));
-
-	if (proc == proc_bottom)
-		panic("Can't return from parent process");
-
-	proc->next = proc_bottom;
-	proc_bottom = proc;
-
-	memcpy(regs, &proc->registers, sizeof(struct regs));
-	paging_switch_directory(proc->cr3);
-}
-
-u32 single_exit(struct regs *regs)
-{
-	u32 hold = regs->ebx;
-	proc_bottom = proc_bottom->next;
-
-	if (proc_bottom == NULL)
-		panic("Return from process with no parent");
-
-	memcpy(regs, &proc_bottom->registers, sizeof(struct regs));
-	paging_switch_directory(proc_bottom->cr3);
-
-	return hold;
-}
\ No newline at end of file
diff --git a/src/kernel/tasks/userspace.h b/src/kernel/tasks/userspace.h
deleted file mode 100644
index d66ba54..0000000
--- a/src/kernel/tasks/userspace.h
+++ /dev/null
@@ -1,17 +0,0 @@
-#ifndef MELVIX_USERSPACE_H
-#define MELVIX_USERSPACE_H
-
-#include <interrupts/interrupts.h>
-#include <stdint.h>
-#include <tasks/process.h>
-
-u32 spawn_child(struct process *child);
-
-void userspace_enter(struct process *proc);
-
-void single_yield(struct process *proc, struct regs *regs);
-u32 single_exit(struct regs *regs);
-
-extern void jump_userspace();
-
-#endif
\ No newline at end of file
diff --git a/src/userspace/programs/init.c b/src/userspace/programs/init.c
index 51aea63..8e5887f 100644
--- a/src/userspace/programs/init.c
+++ b/src/userspace/programs/init.c
@@ -21,6 +21,8 @@ int interrupts_enabled()
 
 void main()
 {
+	while (1) {
+	};
 	if (get_pid() != 1) {
 		printf("Wrong PID!\n");
 		exit(1);