Remove fbdev, add term_getsizes() syscall to get terminal width+height

kernel/syscall/syscall.c

@@ -78,4 +78,5 @@ SyscallFn SYSCALL_TABLE[SYSCALLS_MAX] = {
   [SYS_IPC_MBUSDTTCH]   = &sys_ipc_mbusdttch,
 
   [SYS_TERM_WRITE]    = &sys_term_write,
+  [SYS_TERM_GETSIZES] = &sys_term_getsizes,
 };

kernel/syscall/term.c

@@ -1,6 +1,7 @@
 #include <stdint.h>
 #include <stddef.h>
 #include "syscall/syscall.h"
+#include "bootinfo/bootinfo.h"
 #include "kprintf.h"
 #include "errors.h"
 
@@ -16,3 +17,17 @@ int32_t SYSCALL2(sys_term_write, buffer1, len1) {
 
   return E_OK;
 }
+
+int32_t SYSCALL2(sys_term_getsizes, w1, h1) {
+  uint16_t *w = (uint16_t *)w1;
+  uint16_t *h = (uint16_t *)h1;
+
+  if (w == NULL || h == NULL) {
+    return E_INVALIDARGUMENT;
+  }
+
+  *w = (uint16_t)(BOOT_INFO.fb->width / 16);
+  *h = (uint16_t)(BOOT_INFO.fb->height / 16);
+
+  return E_OK;
+}

kernel/syscall/term.h

@@ -6,5 +6,6 @@
 #include "syscall/syscall.h"
 
 int32_t SYSCALL2(sys_term_write, buffer1, len1);
+int32_t SYSCALL2(sys_term_getsizes, w1, h1);
 
 #endif // SYSCALL_TERM_H_