From 90318f861b20587db3246c2c2344c221ab769ad8 Mon Sep 17 00:00:00 2001
From: Kyle Isom <kyle@imap.cc>
Date: Fri, 24 Jun 2022 14:36:51 -0700
Subject: [PATCH] Add EEPROM image generator.

---
 cmd/eig/main.go | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 cmd/eig/main.go

diff --git a/cmd/eig/main.go b/cmd/eig/main.go
new file mode 100644
index 0000000..a79ecfd
--- /dev/null
+++ b/cmd/eig/main.go
@@ -0,0 +1,52 @@
+package main
+
+import (
+	"flag"
+	"os"
+
+	"git.sr.ht/~kisom/goutils/die"
+)
+
+// size of a kilobit in bytes
+const kilobit = 128
+const pageSize = 4096
+
+func main() {
+	size := flag.Int("s", 256*kilobit, "size of EEPROM image in kilobits")
+	fill := flag.Uint("f", 0, "byte to fill image with")
+	flag.Parse()
+
+	if *fill > 256 {
+		die.With("`fill` argument must be a byte value")
+	}
+
+	path := "eeprom.img"
+
+	if flag.NArg() > 0 {
+		path = flag.Arg(0)
+	}
+
+	fillByte := uint8(*fill)
+
+	buf := make([]byte, pageSize)
+	for i := 0; i < pageSize; i++ {
+		buf[i] = fillByte
+	}
+
+	pages := *size / pageSize
+	last := *size % pageSize
+
+	file, err := os.Create(path)
+	die.If(err)
+	defer file.Close()
+
+	for i := 0; i < pages; i++ {
+		_, err = file.Write(buf)
+		die.If(err)
+	}
+
+	if last != 0 {
+		_, err = file.Write(buf[:last])
+		die.If(err)
+	}
+}