Fixed cnputc crash on 1.76

Author: AlexAltea

build.sh

@@ -25,6 +25,7 @@ make -j4
 
 # Generate GRUB image
 cd ${path_orbital}
+tar -C resources -cf ${path_bin}/memdisk.tar boot
 ${path_grub}/grub-mkimage -d ${path_grub}/grub-core \
-  -O i386-pc -o bin/boot.img -p /boot/grub -c resources/boot.cfg \
-  biosdisk part_msdos part_gpt gfxterm_menu fat bsd
+  -O i386-pc -o bin/boot.img -m bin/memdisk.tar -c resources/boot/grub/boot.cfg \
+  memdisk biosdisk part_msdos part_gpt gfxterm_menu fat tar bsd memrw configfile

orbital-grub

@@ -0,0 +1,3 @@
+korbis (hd0,1)/orbisys-176
+source (memdisk)/boot/grub/env-176.cfg
+boot

resources/boot.cfg

@@ -0,0 +1,13 @@
+# Enable cn_mute flag
+# ===================
+# During initialization in `hammer_time`, the function `pmap_bootstrap` is
+# called which will always call `printf` (and thus `cnputc`) on success.
+# This requires the `cn_devlist` data structure to be filled by `cninit`.
+# However, `cninit` is not called until after `pmap_bootstrap` has returned.
+# To prevent this issue, we manually enable the `cn_mute` flag, which will be
+# set or unset during `cninit` based on boot flags.
+# Values:
+# - 0x0  Disable cn_mute
+# - 0x1  Enable cn_mute
+write_dword 0x32B3A98 0x1
+