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

1 files changed, 36 insertions, 0 deletions

diff --git a/src/kernel/util.c b/src/kernel/util.c
index ea0496e..279616c 100644
--- a/src/kernel/util.c
+++ b/src/kernel/util.c
@@ -2,7 +2,15 @@
 #include <stdint.h>
 #include "drive.h"
 
+#include "log.h"
+#define ACROSS 0x04004e60
+
 void memcpy(void *to, const void *from, uint32_t n) {
+  if (((uint32_t)to <= ACROSS) && ((uint32_t)(to + n) > ACROSS)) {
+    logf(LOG_WARN, "memcpy across 0x%h!", ACROSS);
+    logf(LOG_INFO, "was: memcpy(0x%h, 0x%h, %d)", to, from, n);
+  }
+
   uint32_t *tp = to;
   const uint32_t *fp = from;
   while (n >= 4) {
@@ -39,4 +47,32 @@ void fmcpy(void *to, const struct drive *d, file_id_t f, uint32_t from, uint32_t
 
   d->load_sector(d, f, fsi, buf);
   memcpy(to + i, buf, n);
+}
+
+void mfcpy(const struct drive *d, file_id_t f, uint32_t to, const void *from, uint32_t n) {
+  uint8_t buf[512];
+
+  const uint16_t first_batch = to % 512 + n >= 512 ? 512 - to % 512 : n;
+  if (first_batch) {
+    d->load_sector(d, f, to / 512, buf);
+    memcpy(buf + to % 512, from, first_batch);
+    d->save_sector(d, f, to / 512, buf);
+    n -= first_batch;
+    from += first_batch;
+  }
+
+  uint32_t sector_on = to / 512 + 1;
+  while (n >= 512) {
+    memcpy(buf, from, 512);
+    d->save_sector(d, f, sector_on, buf);
+    n -= 512;
+    from += 512;
+    ++sector_on;
+  }
+
+  if (n) {
+    d->load_sector(d, f, sector_on, buf);
+    memcpy(buf, from, n);
+    d->save_sector(d, f, sector_on, buf);
+  }
 }
\ No newline at end of file