52 lines
1.6 KiB
Forth
52 lines
1.6 KiB
Forth
# Demo of reading and writing to disk.
|
|
#
|
|
# Steps for trying it out:
|
|
# 1. Translate this example into a disk image code.img.
|
|
# ./translate apps/ex9.mu
|
|
# 2. Build a second disk image data.img containing some text.
|
|
# dd if=/dev/zero of=data.img count=20160
|
|
# echo 'abc def ghi' |dd of=data.img conv=notrunc
|
|
# 3. Familiarize yourself with how the data disk looks within xxd:
|
|
# xxd data.img |head
|
|
# 4. Run in an emulator, either Qemu or Bochs.
|
|
# qemu-system-i386 -hda code.img -hdb data.img
|
|
# bochs -f bochsrc.2disks
|
|
# 5. Exit the emulator.
|
|
# 6. Notice that the data disk now contains the word count of the original text.
|
|
# xxd data.img |head
|
|
|
|
fn main screen: (addr screen), keyboard: (addr keyboard), data-disk: (addr disk) {
|
|
var text-storage: (stream byte 0x200)
|
|
var text/esi: (addr stream byte) <- address text-storage
|
|
load-sectors data-disk, 0/lba, 1/num-sectors, text
|
|
|
|
var word-count/eax: int <- word-count text
|
|
|
|
var result-storage: (stream byte 0x10)
|
|
var result/edi: (addr stream byte) <- address result-storage
|
|
write-int32-decimal result, word-count
|
|
store-sectors data-disk, 0/lba, 1/num-sectors, result
|
|
}
|
|
|
|
fn word-count in: (addr stream byte) -> _/eax: int {
|
|
var result/edi: int <- copy 0
|
|
{
|
|
var done?/eax: boolean <- stream-empty? in
|
|
compare done?, 0/false
|
|
break-if-!=
|
|
var g/eax: grapheme <- read-grapheme in
|
|
{
|
|
compare g, 0x20/space
|
|
break-if-!=
|
|
result <- increment
|
|
}
|
|
{
|
|
compare g, 0xa/newline
|
|
break-if-!=
|
|
result <- increment
|
|
}
|
|
loop
|
|
}
|
|
return result
|
|
}
|