nixpkgs/pkgs/misc/drivers/epkowa/firmware_location.patch
Dominik Honnef 55e85a0d62 epkowa: add the GT-S650 plugin
This plugin adds support for the GT-S650, Perfection V19 and
Perfection V39 scanners. I've tested it personally with an Epson
Perfection V39.

This plugin uses the ISCAN_FIRMWARE_DIR environment variable, not
ISCAN_FW_DIR. A quick grep didn't find any use of ISCAN_FW_DIR in the
currently packaged plugins, but a quick Google suggests that this
variable does (or at least used to) exist, so I'm not touching it.
2020-03-20 17:44:20 +01:00

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Diff

Explanation:
in libesci-interpreter-gt-f720.so in
libesci_interpreter_gt_f720_342::libesci_interpreter_gt_f720_348 at 0xdf74: the
binary blob esfw8b.bin is searched either in /usr/share/esci/ or in
$ESCI_FIRMWARE_DIR. But since this library is to be used wia libsane.so in
every binary in the system, we can't wrapProgram the relevant executables to
set this environment variable. Instead, we patch iscan to set this variable
before loading libesci-interpreter-gt-f720.so.
--- backend/channel-usb.c.orig 2017-08-14 11:24:27.669582456 +0200
+++ backend/channel-usb.c 2017-08-14 11:31:40.509010897 +0200
@@ -169,6 +169,10 @@
{
SANE_Status s;
+ setenv("ESCI_FIRMWARE_DIR", NIX_ESCI_PREFIX, 1);
+ setenv("ISCAN_FW_DIR", NIX_ESCI_PREFIX, 1);
+ setenv("ISCAN_FIRMWARE_DIR", NIX_ESCI_PREFIX, 1);
+
s = sanei_usb_open (self->name, &self->fd);
if (SANE_STATUS_GOOD == s)