1 files changed, 42 insertions, 0 deletions
diff --git a/ex2.hex b/ex2.hex
new file mode 100644
index 00000000..6c06565f
--- /dev/null
+++ b/ex2.hex
@@ -0,0 +1,42 @@
+# Test out the video mode by filling in the screen with pixels.
+#
+# To run, first prepare a realistically sized disk image:
+#   dd if=/dev/zero of=disk.img count=20160  # 512-byte sectors, so 10MB
+# Load the program on the disk image:
+#   cat baremetal/boot.hex baremetal/ex2.hex  |./bootstrap run apps/hex  > a.bin
+#   dd if=a.bin of=disk.img conv=notrunc
+# To run:
+#   qemu-system-i386 disk.img
+# Or:
+#   bochs -f baremetal/boot.bochsrc  # boot.bochsrc loads disk.img
+#
+# Expected output:
+#   html/baremetal.png
+
+# main:  (address 0x9400)
+
+# ecx <- LFB
+8b  # copy *rm32 to r32
+  0d  # 00/mod/indirect 001/r32/ecx 101/rm32/use-disp32
+  28 81 00 00 # disp32 [label]
+
+# eax <- LFB + 0xbffff (1024*768 - 1)
+8d  # copy-address rm32 to r32
+  81  # 10/mod/*+disp32 000/r32/eax 001/rm32/ecx
+  ff ff 0b 00  # disp32
+
+# $loop:
+# if (eax < ecx) break
+39  # compare rm32 with r32
+  c8  # 11/mod/direct 001/r32/ecx 000/rm32/eax
+7c 05  # break if < [label]
+# *eax <- al
+88  # copy r8 to m8 at r32
+  00  # 00/mod/indirect 000/r8/AL 000/rm32/eax
+48  # decrement eax
+eb f7  # loop to -9 bytes [label]
+
+# $break:
+e9 fb ff ff ff  # hang indefinitely
+
+# vim:ft=subx