diff --git a/Makefile b/Makefile
index eb6a5cd..7663e96 100644
--- a/Makefile
+++ b/Makefile
@@ -25,8 +25,15 @@ install: writeimg
 	install -m 0755 $< $(DESTDIR)$(PREFIX)/bin/$<
 	install -m 0644 $<.1 $(DESTDIR)$(PREFIX)/share/man/man1/$<.1
 
+# Note that this bypasses PREFIX, since
+# bash does not source /usr/local by default
+install_bash: writeimg_completion_bash.sh
+	install -d $(DESTDIR)/etc/bash_completion.d
+	install -m 0644 $< $(DESTDIR)/etc/bash_completion.d/$<
+
 uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/writeimg
 	rm -f $(DESTDIR)$(PREFIX)/share/man/man1/writeimg.1
+	rm -f $(DESTDIR)/etc/bash_completion.d/writeimg*
 
 .PHONY: clean install uninstall
diff --git a/README.md b/README.md
index 6dfebd5..f864c59 100644
--- a/README.md
+++ b/README.md
@@ -1,13 +1,17 @@
-# Simple dd-like image writer with additional security checks.
+# WriteIMG Image Writer
 
-This tool verifies your image automatically. The block size is currently set to
-1 MiB, which should be enough to avoid trouble.
+WriteIMG is a simple dd-like image writer with additional security checks for
+Linux and soon FreeBSD. It tells you what you're about to do and warns you
+about potential problems before they occur. It also features automatic image
+verifications, and uses a suitable block size for fast and gentle writing.  
+
+Say goodbye to fried flash and overwritten bootloaders, no more footguns!
 
 ```
-writeimg v0.2.0, Rev. 5323932-dirty
+WriteIMG v0.2.3, Rev. d02fc5f
 In honor of SwePwnage - the OG disk destroyer
 Copyright (C) 2026 Imbus, BSD-2-Clause
-Build date: 2026-02-07
+Build date: 2026-02-21
 
 Usage:
    writeimg [-v] -d <device> <file.img>
@@ -17,12 +21,18 @@ Args:
    -v                  Verify only
    -d device           Target block device
    -h, --help          Print this help message
-   -n, --noconfirm     Do not ask for premission
+   -n, --noconfirm     Do not ask for permission
    -V, --version       Print version
 ```
 
+We also provide a manpage, which targets OpenBSD-level quality. Incorrect or
+outdated information is a bug.
+
 ## Testing
 
+For testing, there is a shell script "test.sh" included. It sets up a block dev
+and writes (and verifies) a bunch of nonsense to it. It boils down to:
+
 ```
 dd if=/dev/zero of=./disk.img bs=1M count=1024
 losetup -fP ./disk.img
@@ -30,6 +40,75 @@ losetup -a
 losedup -d /dev/loop0
 ```
 
+Writes to a regular files is not currently in scope, although it would simplify
+testing.
+
+## Design Considerations
+
+Most of the sanity checking is currently highly Linux specific. We should
+prefer general/posix solutions that reach **at least** FreeBSD, preferably
+OpenBSD and Solaris as well. FreeBSD did implement procfs, but its a Linux-ism
+and it has since been deprecated. I would prefer not to turn this rather simple
+code into macro-mozaic, as i've seen other similar projects do. After all, this
+is just a juiced-up dd-rewrite at its core.  
+
+**Apple products are unsupported.** Im simply not interested in ensuring
+compatibility with a walled-garden ecosystem. If *you* are, we can change that.  
+
+At the time of writing, my FreeBSD server is down for maintenance, which means
+all of my development and testing is focused on AMD64, AArch64 and AArch32
+Linux.  
+
+In the setup phase of the program, we can absolutely afford to do lots of
+sanity checking via syscalls. Between each block write, we flush the disk
+buffers. These flushes are larger (1 MiB when buffer is full) than the sector
+size (often 4k or 64k) of the flash, so as far as i know, this is a gentle way
+to write flash, and should not incur any significant performance overhead. 1
+MiB is also a multiple of the most common sector sizes. We could write it all
+with no flushing, but that would mean the progress indicator will measure
+buffered writes, which is useless.  
+
+It should be possible to induce optimal block size, but this idea has not been
+explored yet.  
+
+Currently when verifying the written data, we read from both the input file and
+the output block device and do a byte-by-byte comparison. A CRC32 is also
+calculated in the first pass of the input file read. In the second pass (the
+verification stage), we calculate the CRC32 of the block device data and
+compare that to our previous result. **This means that we currently use two
+separate methods of verification**. The program allocates **two** separate
+buffers in the startup phase for comparisons. This will change in the coming
+releases, and we will rely only on the CRC.  
+
+De-allocation is handled in the interrupt vector as well as in the 'sad-paths',
+but ultimately this program can be regarded as samurai-principled. We try to
+handle deallocation, but exit on failure and let the kernel handle the rest.  
+
+The use of a crypto-grade checksumming algorithm was considered, but was
+ultimately rejected in favour of a lookup based CRC32. Its simpler, faster and
+easier to understand (See: [crc32.h](./crc32.h)). We may include a compile-time
+option to disable the lookup table to reduce size for really small targets, but
+we speculate that those targets are already satisfied with busybox-dd.  
+
+We also considered using libudev or any of its analogues, to determine the type
+of block device (spinning or flash), but my somewhat inconclusive research
+indicates that it does not include functionality to determine the medium type
+(usb/sd/sata), which is ultimately what i would like to warn the user about.
+The libudev library is also Linux specific.  
+
+We also need completion scripts for the most common shells. This includes csh,
+bash and zsh. Should be easy enough when we set our minds to it.  
+
+See:
+ - `grep -nE 'BLK[A-Za-z0-9]+' /usr/include/linux/fs.h`  
+   In particular, we're interested in BLKGETSIZE64 and BLKFLSBUF for now.
+
+We can read the device info from:
+ - /sys/class/block/[name]/*
+Like:
+ - /sys/class/block/[name]/device/model
+ - /sys/class/block/[name]/size
+
 ## Inspiration
 
 See:
diff --git a/test.sh b/test.sh
index 70cfae9..1eb6280 100644
--- a/test.sh
+++ b/test.sh
@@ -4,13 +4,17 @@ set -e
 # set -x # For debugging
 
 # If you ever mess this up:
-#  $ sudo mknod /dev/loop-control c 10 237
-#  $ sudo chmod 600 /dev/loop-control
-#  $ sudo chown root:root /dev/loop-control
+#  $ mknod /dev/loop-control c 10 237
+#  $ chmod 600 /dev/loop-control
+#  $ chown root:root /dev/loop-control
 #
 # For cleanup:
-#  $ sudo find /dev -maxdepth 1 -type b -name 'loop[0-9]*' -exec rm -f {} \;
+#  $ find /dev -maxdepth 1 -type b -name 'loop[0-9]*' -exec rm -f {} \;
 
+if [ "$(id -u)" -ne 0 ]; then
+    echo "Run as root. We need permissions to write and setup a loop device."
+    exit 1
+fi
 
 DISKFILE="/tmp/disk.img"
 BINFILE="/tmp/file.bin"
@@ -22,9 +26,9 @@ echo "Using device: ${LOOPDEV}"
 cleanup() {
     echo "Cleaning up..."
     set +e -x
-    sudo losetup -d ${LOOPDEV}
-    sudo rm ${LOOPDEV}
-    sudo rm ${BINFILE} ${DISKFILE}
+    losetup -d ${LOOPDEV}
+    rm ${LOOPDEV}
+    rm ${BINFILE} ${DISKFILE}
 }
 
 trap cleanup EXIT INT TERM
@@ -36,28 +40,31 @@ if losetup ${LOOPDEV} >/dev/null 2>&1; then
 fi
 
 if [ ! -f ${DISKFILE} ]; then
+    echo "Creating ${DISKFILE}"
     dd if=/dev/zero of=${DISKFILE} bs=1M count=256
 fi
 
 if [ ! -f ${BINFILE} ]; then
+    echo "Creating ${BINFILE}"
     dd if=/dev/urandom of=${BINFILE} bs=1M count=64
 fi
 
 if [ ! -e ${LOOPDEV} ]; then
-    sudo losetup ${LOOPDEV} ${DISKFILE}
+    mknod ${LOOPDEV} b 7 ${LOOPNUM} # busybox needs this
+    losetup ${LOOPDEV} ${DISKFILE}
 fi
 
-sudo ./writeimg -nd ${LOOPDEV} ${BINFILE}
-sudo ./writeimg -vnd ${LOOPDEV} ${BINFILE}
+./writeimg -nd ${LOOPDEV} ${BINFILE}
+./writeimg -vnd ${LOOPDEV} ${BINFILE}
 
-sudo ./writeimg -nd ${LOOPDEV} ./writeimg
-sudo ./writeimg -vnd ${LOOPDEV} ./writeimg
+./writeimg -nd ${LOOPDEV} ./writeimg
+./writeimg -vnd ${LOOPDEV} ./writeimg
 
-sudo ./writeimg -nd ${LOOPDEV} ./LICENSE
-sudo ./writeimg -vnd ${LOOPDEV} ./LICENSE
+./writeimg -nd ${LOOPDEV} ./LICENSE
+./writeimg -vnd ${LOOPDEV} ./LICENSE
 
 # Redirect this to avoid confusion
-! sudo ./writeimg -vnd ${LOOPDEV} ./crc32.h 2>/dev/null
+! ./writeimg -vnd ${LOOPDEV} ./crc32.h 2>/dev/null
 
 GREEN="\e[32m"
 RESET="\e[0m"
diff --git a/writeimg.c b/writeimg.c
index e839930..2219acb 100644
--- a/writeimg.c
+++ b/writeimg.c
@@ -72,7 +72,7 @@ const char help[] =
     "   -v                  Verify only\n"
     "   -d device           Target block device\n"
     "   -h, --help          Print this help message\n"
-    "   -n, --noconfirm     Do not ask for premission\n"
+    "   -n, --noconfirm     Do not ask for permission\n"
     "   -V, --version       Print version\n"
     "\0";
 // clang-format on
@@ -278,7 +278,11 @@ int main(int argc, char *argv[]) {
             exit(EXIT_FAILURE);
         }
 
+#ifdef __GLIBC__
         if (ioctl(fd, BLKGETSIZE64, &device_size) < 0) {
+#else /* With musl, ioctl's take ints, kheaders provide unsigned longs. Passes tests. */
+        if (ioctl(fd, (int)BLKGETSIZE64, &device_size) < 0) {
+#endif
             perror("ioctl");
             close(fd);
             exit(EXIT_FAILURE);
diff --git a/writeimg_completion_bash.sh b/writeimg_completion_bash.sh
new file mode 100644
index 0000000..305cf95
--- /dev/null
+++ b/writeimg_completion_bash.sh
@@ -0,0 +1,25 @@
+_writeimg_completion() {
+    local cur prev opts
+
+    cur="${COMP_WORDS[COMP_CWORD]}"
+    prev="${COMP_WORDS[COMP_CWORD-1]}"
+
+    opts="-v -d -h --help -n --noconfirm -V --version"
+
+    # Devices
+    if [[ "$prev" == "-d" ]]; then
+        COMPREPLY=( $(compgen -W "$(ls -d /dev/sd* /dev/nvme* /dev/mmcblk* 2>/dev/null)" -- "$cur") )
+        return 0
+    fi
+
+    # Flags
+    if [[ "$cur" != -* ]]; then
+        COMPREPLY=( $(compgen -f -- "$cur") )
+        return 0
+    fi
+
+    # Files
+    COMPREPLY=( $(compgen -W "$opts" -- "$cur") )
+}
+
+complete -F _writeimg_completion writeimg