7403 - baremetal/ for apps without a kernel

11 files changed, 16 insertions, 12 deletions

diff --git a/baremetal/README.md b/baremetal/README.md
new file mode 100644
index 00000000..af45760c
--- /dev/null
+++ b/baremetal/README.md
@@ -0,0 +1,2 @@
+Some apps written in SubX and Mu. Where the rest of this repo relies on a few
+Linux syscalls, the apps in this subdirectory interface directly with hardware.
diff --git a/apps/boot.bochsrc b/baremetal/boot.bochsrc
index 521e22d9..521e22d9 100644
--- a/apps/boot.bochsrc
+++ b/baremetal/boot.bochsrc
diff --git a/apps/boot.hex b/baremetal/boot0.hex
index 8b11dbab..793b2b9f 100644
--- a/apps/boot.hex
+++ b/baremetal/boot0.hex
@@ -1,8 +1,10 @@
-# Bootable image that:
+# A minimal bootable image that:
 #   - loads more sectors past the first boot sector (using BIOS primitives)
 #   - switches to 32-bit mode (giving up access to BIOS primitives)
 #   - sets up a handler for keyboard events
-#   - as an example program, prints alphabets to the top-left position on screen (by writing to memory-mapped VGA memory) as they're typed
+#   - as an example program, prints '1' to the top-left position on screen (by writing to memory-mapped VGA memory) when the '1' key is typed
+#
+# When it's ready to accept keys, it prints 'H' to the top-left of the screen.
 #
 # If the initial load fails, it prints 'D' to the top-left of the screen and
 # halts.
@@ -10,12 +12,12 @@
 # To convert to a disk image, first prepare a realistically sized disk image:
 #   dd if=/dev/zero of=disk.img count=20160  # 512-byte sectors, so 10MB
 # Now fill in sectors:
-#   ./bootstrap run apps/hex < apps/boot.hex > boot.bin
+#   ./bootstrap run apps/hex < baremetal/boot0.hex > boot.bin
 #   dd if=boot.bin of=disk.img conv=notrunc
 # To run:
 #   qemu-system-i386 disk.img
 # Or:
-#   bochs -f apps/boot.bochsrc  # boot.bochsrc loads disk.img
+#   bochs -f baremetal/boot.bochsrc  # boot.bochsrc loads disk.img
 #
 # Since we start out in 16-bit mode, we need instructions SubX doesn't
 # support.
@@ -264,7 +266,7 @@ e9 fb ff ff ff  # loop forever
 55 aa
 
 ## sector 2
-# not loaded on boot; loaded by load_disk
+# loaded by load_disk, not automatically on boot
 
 # offset 200 (address 0x7e00): interrupt descriptor table
 # 32 entries * 8 bytes each = 256 bytes (0x100)
diff --git a/apps/bos/3-1.hex b/baremetal/bos/3-1.hex
index 75e10c1f..bf4ef208 100644
--- a/apps/bos/3-1.hex
+++ b/baremetal/bos/3-1.hex
@@ -3,11 +3,11 @@
 # 16-bit real mode.
 #
 # To convert to a disk image:
-#   ./bootstrap run apps/hex < apps/bos/3-1.hex > boot.bin
+#   ./bootstrap run apps/hex < baremetal/bos/3-1.hex > boot.bin
 # To run:
 #   qemu-system-i386 boot.bin
 # Or:
-#   bochs -f apps/bos/bochsrc  # bochsrc loads boot.bin
+#   bochs -f baremetal/bos/bochsrc  # bochsrc loads boot.bin
 #
 # Expected output inside emulator:
 #   Booting from floppy...
diff --git a/apps/bos/3-2.hex b/baremetal/bos/3-2.hex
index a52d2a88..85792e26 100644
--- a/apps/bos/3-2.hex
+++ b/baremetal/bos/3-2.hex
@@ -3,11 +3,11 @@
 # 16-bit real mode.
 #
 # To convert to a disk image:
-#   ./bootstrap run apps/hex < apps/bos/3-2.hex > boot.bin
+#   ./bootstrap run apps/hex < baremetal/bos/3-2.hex > boot.bin
 # To run:
 #   qemu-system-i386 boot.bin
 # Or:
-#   bochs -f apps/bos/bochsrc  # bochsrc loads boot.bin
+#   bochs -f baremetal/bos/bochsrc  # bochsrc loads boot.bin
 #
 # Expected output inside emulator:
 #   Hello
diff --git a/apps/bos/32bit.hex b/baremetal/bos/32bit.hex
index e8b1f21a..5a85aa36 100644
--- a/apps/bos/32bit.hex
+++ b/baremetal/bos/32bit.hex
@@ -2,11 +2,11 @@
 # Must have exactly 512 bytes.
 #
 # To convert to a disk image:
-#   ./bootstrap run apps/hex < apps/bos/32bit.hex > boot.bin
+#   ./bootstrap run apps/hex < baremetal/bos/32bit.hex > boot.bin
 # To run:
 #   qemu-system-i386 boot.bin
 # Or:
-#   bochs -f apps/bos/bochsrc  # bochsrc loads boot.bin
+#   bochs -f baremetal/bos/bochsrc  # bochsrc loads boot.bin
 #
 # Expected output inside emulator:
 #   H
diff --git a/apps/bos/4.asm b/baremetal/bos/4.asm
index 71c51d97..71c51d97 100644
--- a/apps/bos/4.asm
+++ b/baremetal/bos/4.asm
diff --git a/apps/bos/4.xxd b/baremetal/bos/4.xxd
index be677134..be677134 100644
--- a/apps/bos/4.xxd
+++ b/baremetal/bos/4.xxd
diff --git a/apps/bos/README.md b/baremetal/bos/README.md
index 989ebf44..989ebf44 100644
--- a/apps/bos/README.md
+++ b/baremetal/bos/README.md
diff --git a/apps/bos/bochsrc b/baremetal/bos/bochsrc
index de225b4c..de225b4c 100644
--- a/apps/bos/bochsrc
+++ b/baremetal/bos/bochsrc
diff --git a/apps/bos/print-mem-real-mode.hex b/baremetal/bos/print-mem-real-mode.hex
index 5e41d5b3..3610308c 100644
--- a/apps/bos/print-mem-real-mode.hex
+++ b/baremetal/bos/print-mem-real-mode.hex
@@ -1,7 +1,7 @@
 # Experiment: write to video RAM from 16-bit real mode. And it works.
 #
 # To convert to a disk image:
-#   ./bootstrap run apps/hex < apps/bos/print-mem-real-mode.hex > boot.bin
+#   ./bootstrap run apps/hex < baremetal/bos/print-mem-real-mode.hex > boot.bin
 # To run:
 #   qemu-system-i386 boot.bin
 # Or: