4 files changed, 30 insertions, 29 deletions
diff --git a/.gitignore b/.gitignore
index a5d1bde8..3bcf7b3f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,4 @@
 /build
 /clone
 /git
-/pdf
 /trash
diff --git a/pdf.sh b/pdf.sh
deleted file mode 100755
index 90c73de1..00000000
--- a/pdf.sh
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/bin/sh
-set -e -u
-
-mkdir -p pdf
-
-fetch() {
-	[ -f "pdf/$1" ] && return
-	curl --silent --show-error --output "pdf/$1" "$2"
-	echo "pdf/$1"
-}
-
-elf() {
-	fetch "$1" "http://refspecs.linuxbase.org/elf/$2"
-}
-intel() {
-	fetch "$1" "https://software.intel.com/sites/default/files/managed/$2"
-}
-
-elf abi.pdf x86_64-abi-0.99.pdf
-elf elf.pdf elf.pdf
-fetch multiboot.pdf 'https://www.gnu.org/software/grub/manual/multiboot/multiboot.pdf'
-intel intel-64-opt.pdf 9e/bc/64-ia-32-architectures-optimization-manual.pdf
-intel intel-64-sdm-vol-1.pdf a4/60/253665-sdm-vol-1.pdf
-intel intel-64-sdm-vol-2.pdf a4/60/325383-sdm-vol-2abcd.pdf
-intel intel-64-sdm-vol-3.pdf a4/60/325384-sdm-vol-3abcd.pdf
-intel intel-64-sdm-vol-4.pdf 22/0d/335592-sdm-vol-4.pdf
-
-chmod 444 pdf/*.pdf
diff --git a/pdf/.gitignore b/pdf/.gitignore
new file mode 100644
index 00000000..a1363379
--- /dev/null
+++ b/pdf/.gitignore
@@ -0,0 +1 @@
+*.pdf
diff --git a/pdf/Makefile b/pdf/Makefile
new file mode 100644
index 00000000..6d1d1561
--- /dev/null
+++ b/pdf/Makefile
@@ -0,0 +1,29 @@
+PDFS += abi.pdf
+PDFS += elf.pdf
+PDFS += intel-64-opt.pdf
+PDFS += intel-64-sdm-vol-1.pdf
+PDFS += intel-64-sdm-vol-2.pdf
+PDFS += intel-64-sdm-vol-3.pdf
+PDFS += intel-64-sdm-vol-4.pdf
+PDFS += multiboot.pdf
+
+ELF = http://refspecs.linuxbase.org/elf
+INTEL = https://software.intel.com/sites/default/files/managed
+
+URL_abi.pdf = ${ELF}/x64_64-abi-0.99.pdf
+URL_elf.pdf = ${ELF}/elf.pdf
+URL_intel-64-opt.pdf = ${INTEL}/9e/bc/64-ia-32-architectures-optimization-manual.pdf
+URL_intel-64-sdm-vol-1.pdf = ${INTEL}/a4/60/253665-sdm-vol-1.pdf
+URL_intel-64-sdm-vol-2.pdf = ${INTEL}/a4/60/325383-sdm-vol-2abcd.pdf
+URL_intel-64-sdm-vol-3.pdf = ${INTEL}/a4/60/325384-sdm-vol-3abcd.pdf
+URL_intel-64-sdm-vol-4.pdf = ${INTEL}/22/0d/335592-sdm-vol-4.pdf
+URL_multiboot.pdf = https://www.gnu.org/software/grub/manual/multiboot/multiboot.pdf
+
+all: ${PDFS}
+
+${PDFS}:
+	curl -o $@ ${URL_$@}
+	chmod 444 $@
+
+clean:
+	rm -f ${PDFS}