syscalls and page fault take a register_state_t* instead of registers…

…_state_t

README.md

@@ -13,6 +13,7 @@ Features
 * Compositing window manager with clipping and alpha blending
 * Text renderer with SSAA antialiasing
 * Auto-boots in 1024x768 full RGB
+* FAT filesystem with IDE hard-drive driver, and an initrd.
 * ELF loader
 * Newlib port
 * MLFQ scheduler

src/kernel/interrupts/int_handler_stubs.s

@@ -158,7 +158,7 @@ irq_common_stub:
 
     call irq_receive
 
-    ; push registers_t* arg back into esp
+    ; pop registers_t* arg back into esp
     pop esp
 
     ; restore data segment selector

src/kernel/interrupts/interrupts.c

@@ -81,6 +81,7 @@ void irq_receive(register_state_t* regs) {
 	}
 
     pic_signal_end_of_interrupt(int_no);
+
 	return ret;
 }
 

src/kernel/syscall/syscall.c

@@ -8,7 +8,7 @@
 
 #define MAX_SYSCALLS 128
 
-static int syscall_handler(register_state_t regs);
+static int syscall_handler(register_state_t* regs);
 
 array_m* syscalls = {0};
 
@@ -33,16 +33,16 @@ void syscall_add(void* syscall) {
 	array_m_insert(syscalls, syscall);
 }
 
-static int syscall_handler(register_state_t regs) {
+static int syscall_handler(register_state_t* regs) {
 	//check requested syscall number
 	//stored in eax
-	if (!syscalls || regs.eax >= MAX_SYSCALLS) {
-		printf_err("Syscall %d called but not defined", regs.eax);
+	if (!syscalls || regs->eax >= MAX_SYSCALLS) {
+		printf_err("Syscall %d called but not defined", regs->eax);
 		return -1;
 	}
 
 	//location of syscall funcptr
-	int (*location)() = (int(*)())array_m_lookup(syscalls, regs.eax);
+	int (*location)() = (int(*)())array_m_lookup(syscalls, regs->eax);
 
 	//we don't know how many arguments the function wants.
 	//so just push them all on the stack in correct order
@@ -61,7 +61,7 @@ static int syscall_handler(register_state_t regs) {
 		pop %%ebx;	\
 		pop %%ebx;	\
 		pop %%ebx;	\
-	" : "=a" (ret) : "r" (regs.edi), "r" (regs.esi), "r" (regs.edx), "r" (regs.ecx), "r" (regs.ebx), "r" (location));
-	regs.eax = ret;
+	" : "=a" (ret) : "r" (regs->edi), "r" (regs->esi), "r" (regs->edx), "r" (regs->ecx), "r" (regs->ebx), "r" (location));
+	regs->eax = ret;
 	return ret;
 }

src/kernel/vmm/vmm.c

@@ -12,7 +12,7 @@
 #define PAGES_IN_PAGE_TABLE 1024
 #define PAGE_TABLES_IN_PAGE_DIR 1024
 
-static void page_fault(register_state_t regs);
+static void page_fault(const register_state_t* regs);
 static uint32_t vmm_page_table_idx_for_virt_addr(uint32_t addr);
 static uint32_t vmm_page_idx_within_table_for_virt_addr(uint32_t addr);
 static void vmm_page_table_alloc_for_virt_addr(vmm_pdir_t* dir, uint32_t addr);
@@ -117,18 +117,18 @@ uint32_t vmm_get_phys_for_virt(uint32_t virtualaddr) {
     return (uint32_t)((pt[ptindex] & ~0xFFF) + ((unsigned long)virtualaddr & 0xFFF));
 }
 
-static void page_fault(register_state_t regs) {
+static void page_fault(const register_state_t* regs) {
 	//page fault has occured
 	//faulting address is stored in CR2 register
 	uint32_t faulting_address;
 	asm volatile("mov %%cr2, %0" : "=r" (faulting_address));
 
 	//error code tells us what happened
-	int present = !(regs.err_code & 0x1); //page not present
-	int rw = regs.err_code & 0x2; //write operation?
-	int us = regs.err_code & 0x4; //were we in user mode?
-	int reserved = regs.err_code & 0x8; //overwritten CPU-reserved bits of page entry?
-	int id = regs.err_code & 0x10; //caused by instruction fetch?
+	int present = !(regs->err_code & 0x1); //page not present
+	int rw = regs->err_code & 0x2; //write operation?
+	int us = regs->err_code & 0x4; //were we in user mode?
+	int reserved = regs->err_code & 0x8; //overwritten CPU-reserved bits of page entry?
+	int id = regs->err_code & 0x10; //caused by instruction fetch?
 
 	//if this page was present, attempt to recover by allocating the page
 	if (present) {
@@ -152,10 +152,10 @@ static void page_fault(register_state_t regs) {
 	if (reserved) printf_err("Overwrote CPU-resereved bits of page entry");
 	if (id) printf_err("Faulted during instruction fetch");
 
-	bool caused_by_execution = (regs.eip == faulting_address);
+	bool caused_by_execution = (regs->eip == faulting_address);
 	printf("Caused by %s unpaged memory\n", caused_by_execution ? "executing" : "reading");
     printf("Kernel spinlooping due to unhandled page fault\n");
-    asm("sti");
+    //asm("sti");
     while (1) {}
 }