minimal file writing, shutdown keybinding (Win+Shift+Q)

1 files changed, 26 insertions, 1 deletions

diff --git a/src/kernel/idt.c b/src/kernel/idt.c
index c79ae7b..1a78da0 100644
--- a/src/kernel/idt.c
+++ b/src/kernel/idt.c
@@ -52,6 +52,12 @@ uint32_t sc_file_get_size(uint32_t handle) {
   return drives[handle >> 8].get_file_length(drives + (handle >> 8), handle & 0xff);
 }
 
+void sc_file_set_size(uint32_t handle, uint32_t new_size) {
+  if (!handle)
+    return;
+  drives[handle >> 8].set_file_length(drives + (handle >> 8), handle & 0xff, new_size);
+}
+
 uint32_t sc_file_read(uint32_t handle, uint32_t file_offset, uint32_t count, void *buffer) {
   if (!handle)
     return 0;
@@ -62,6 +68,23 @@ uint32_t sc_file_read(uint32_t handle, uint32_t file_offset, uint32_t count, voi
   return count;
 }
 
+uint32_t sc_file_write(uint32_t handle, uint32_t file_offset, uint32_t count, void *buffer) {
+  if (!handle)
+    return 0;
+  const struct drive *const d = drives + (handle >> 8);
+  const fs_id_t fid = handle & 0xff;
+
+  if (!d->is_writable(d, fid))
+    return 0;
+
+  const uint32_t l = d->get_file_length(d, fid);
+  if (file_offset + count > l)
+    count = l - file_offset;
+
+  mfcpy(d, fid, file_offset, buffer, count);
+  return count;
+}
+
 uint32_t sc_start_task(uint32_t drive_number, char *path, const char *pass, uint32_t io_task) {
   switch_to_kernel_cr3();
   uint32_t process_id = try_elf_run(drives + drive_number, vma_to_pma(active_task->page_directory, path), pass, io_task);
@@ -183,7 +206,9 @@ void const *syscall_table[] = {
   &find_unread_ipc,
   &sc_wait_ipc_read,
   &sc_is_task_running,
-  &sc_get_timestamp
+  &sc_get_timestamp,
+  &sc_file_write,
+  &sc_file_set_size
 };
 
 //these aren't really void ()'s, but gcc complains if we take an address of a void, so we give it a type