Begin implementation of syscalls.

2 files changed, 89 insertions, 1 deletions

diff --git a/src/kernel/user/process.c b/src/kernel/user/process.c
index 0f4892d..579c33d 100644
--- a/src/kernel/user/process.c
+++ b/src/kernel/user/process.c
@@ -118,6 +118,10 @@ pagedir_t *proc_pagedir(process_t *p) {
 	return p->pd;
 }
 
+int proc_pid(process_t *p) {
+	return p->pid;
+}
+
 // ================================== //
 // MANAGING FILESYSTEMS FOR PROCESSES //
 // ================================== //
@@ -143,7 +147,7 @@ fs_t *proc_find_fs(process_t *p, const char* name) {
 // USER MEMORY REGION MANAGEMENT //
 // ============================= //
 
-static user_region_t *find_user_region(process_t *proc, void* addr) {
+static user_region_t *find_user_region(process_t *proc, const void* addr) {
 	for (user_region_t *it = proc->regions; it != 0; it = it->next) {
 		if (addr >= it->addr && addr < it->addr + it->size) return it;
 	}
@@ -287,4 +291,24 @@ static void proc_usermem_pf(void* p, registers_t *regs, void* addr) {
 	}
 }
 
+void probe_for_read(const void* addr, size_t len) {
+	process_t *proc = current_process();
+	user_region_t *r = find_user_region(proc, addr);
+	if (r == 0 || addr + len > r->addr + r->size || !(r->mode & MM_READ)) {
+		dbg_printf("Access violation on read at 0x%p len 0x%p in process %d : exiting.\n",
+			addr, len, proc->pid);
+		exit();
+	}
+}
+
+void probe_for_write(const void* addr, size_t len) {
+	process_t *proc = current_process();
+	user_region_t *r = find_user_region(proc, addr);
+	if (r == 0 || addr + len > r->addr + r->size || !(r->mode & MM_WRITE)) {
+		dbg_printf("Access violation on write at 0x%p len 0x%p in process %d : exiting.\n",
+			addr, len, proc->pid);
+		exit();
+	}
+}
+
 /* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/src/kernel/user/syscall.c b/src/kernel/user/syscall.c
new file mode 100644
index 0000000..563957c
--- /dev/null
+++ b/src/kernel/user/syscall.c
@@ -0,0 +1,64 @@
+#include <string.h>
+#include <process.h>
+#include <vfs.h>
+
+#include <syscall.h>
+
+typedef uint32_t (*syscall_handler_t)(uint32_t, uint32_t, uint32_t, uint32_t, uint32_t);
+
+static syscall_handler_t sc_handlers[SC_MAX] = { 0 };
+
+// ==================== //
+// THE SYSCALLS CODE !! //
+// ==================== //
+
+static uint32_t exit_sc(uint32_t code, uint32_t uu1, uint32_t uu2, uint32_t uu3, uint32_t uu4) {
+	dbg_printf("Proc %d exit with code %d\n", proc_pid(current_process()), code);
+	// TODO : use code... and process exiting is not supposed to be done this way
+
+	exit();
+	return 0;
+}
+
+static uint32_t yield_sc() {
+	yield();
+	return 0;
+}
+
+static uint32_t dbg_print_sc(uint32_t x, uint32_t uu1, uint32_t uu2, uint32_t uu3, uint32_t uu4) {
+	const char* addr = (const char*)x;
+	probe_for_read(addr, 256);
+
+	char buf[256];
+	memcpy(buf, addr, 256);
+	buf[255] = 0;
+
+	dbg_print(buf);
+
+	return 0;
+}
+
+// ====================== //
+// SYSCALLS SETUP ROUTINE //
+// ====================== //
+
+void setup_syscalls() {
+	sc_handlers[SC_EXIT] = exit_sc;
+	sc_handlers[SC_YIELD] = yield_sc;
+	sc_handlers[SC_DBG_PRINT] = dbg_print_sc;
+}
+
+void syscall_handler(registers_t *regs) {
+	ASSERT(regs->int_no == 64);
+
+	if (regs->eax < SC_MAX) {
+		syscall_handler_t h = sc_handlers[regs->eax];
+		if (h != 0) {
+			regs->eax = h(regs->ebx, regs->ecx, regs->edx, regs->esi, regs->edi);
+		} else {
+			regs->eax = -1;
+		}
+	}
+}
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/