1FXLOAD(8) Linux Programmer's Manual FXLOAD(8)
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6 fxload - Firmware download to EZ-USB devices
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9 fxload [ -v ] [ -D devpath ] [ -I hexfile ] [ -t type ] [ -c config ] [
10 -s loader ]
11 fxload [ -D devpath ] [ -L link ] [ -m mode ]
12 fxload [ -V ]
13
15 fxload is a program which downloads firmware to USB devices based on
16 AnchorChips EZ-USB, Cypress EZ-USB FX, or Cypress EZ-USB FX2 microcon‐
17 trollers. These have 8-bit 8051 cores with special extensions for USB
18 I/O. The FX2 supports high speed USB 2.0 transfers (480 Mbit/sec) as
19 well as full speed USB 1.1 transfers (12 Mbit/sec), while the earlier
20 parts supports only full speed transfers. These controllers have sev‐
21 eral package options, and can be set up with external memory (on-chip
22 memory is usually about 8K), EEPROMs, and ROMs when device costs allow.
23 This uses "usbfs" (older name: "usbdevfs") to access devices, and
25 issues vendor specific control requests to download and reset the EZ-
26 USB devices. Normally, firmware will then "renumerate" by disconnect‐
27 ing from USB and then reconnecting as a new device. It then appears
28 with new device descriptors and functionality, as provided by the
29 firmware which has been downloaded.
30 To support some non-firmware applications, this can also set up sym‐
32 bolic links for those usbfs names. It can also change their access
33 modes. Both of these can help simplify software applications that need
34 to talk to USB devices using user mode drivers, don't want to run with
35 privileges or to examine all of the existing USB devices, and which
36 don't need more kernel drivers.
37 See the Linux-Hotplug web site for information about how to use fxload
39 to download device firmware when hotplugging USB devices, using driver-
40 specific scripts stored in the /etc/hotplug/usb directory.
41
43 At least one of the following options must be specified. Note that as
44 usual with UNIX and Linux commands, the order of command option flags
45 does not matter. You may use these in any order.
46 -I hexfile
48 Downloads the specified firmware file. This firmware is pro‐
49 vided in standard Intel hexfile format. (Common naming conven‐
50 tions include *.hex and *.ihx.) Depending on the device and
51 firmware in use, the -s option may also be necessary to specify
52 a second stage loader. Firmware is normally downloaded to RAM
53 and executed, but there is also an option for downloading into
54 bootable I2C EEPROMs.
55 -L link
57 Creates the specified symbolic link to the usbfs device path.
58 This would typically be used to create a name in a directory
59 that would be searched by an application. The symlink would be
60 removed by some other component on device unplug.
61 -m mode
63 Changes permissions on the "usbfs" device node. By default,
64 those nodes are only accessible by privileged users, which
65 doesn't help when the user mode device driver needs to run with‐
66 out root privileges. Note that usbfs mount options like dev‐
67 mode=0666 are also available.
68 -V Identifies the version of fxload being invoked, and exits with‐
70 out performing other actions.
71 Note that when downloading firmware that renumerates, there's no point
73 in changing the device permissions or creating a symbolic link.
74
76 By default, fxload assumes the device uses an EZ-USB or EZ-USB FX. It
77 also assumes that the device in question has been specified by USB ker‐
78 nel hotplugging conventions, using the DEVICE environment variable to
79 name a "usbfs" file that can be used to talk to the device.
80 -c config
82 Indicates the specified firmware should be downloaded to an I2C
83 boot EEPROM rather than to RAM. The parameter is the EZ-USB FX
84 or FX2 configuration byte, and for AnchorChips devices the value
85 should be zero. This requires a second stage loader that knows
86 how to write to I2C EEPROMs specified using the -s option, as
87 well as a device that's provided with an EEPROM large enough to
88 store the boot firmware. After downloading to a device's EEP‐
89 ROM, you should retest it starting from power off.
90 -s loader
92 This identifies the hex file holding a second stage loader (in
93 the same hex file format as the firmware itself), which is
94 loaded into internal memory. This loader understands additional
95 vendor control requests, beyond the one built into all EZ-USB
96 hardware, which are needed to write external RAM or EEPROM. As
97 a last step when loading firmware, fxload normally overwrites
98 this second stage loader with parts of the firmware residing on-
99 chip.
100 -t type
102 Indicates which type of microcontroller is used in the device;
103 type may be one of an21 (the original AnchorChips devices), fx
104 (Cypress' updated version, the EZ-USB FX), or fx2 (the Cypress
105 EZ-USB FX2, supporting high speed transfers). Except when writ‐
106 ing to EEPROM, all that normally matters when downloading
107 firmware is whether or not the device uses an FX2.
108 -v Prints some diagnostics, such as download addresses and sizes,
110 to standard error. Repeat the flag (-vv, -vvv) to get more
111 diagnostics.
112 -D devpath
114 Specifies the "usbfs" path name for the device in question, such
115 as /proc/bus/usb/004/080. This takes precedence over any DEVICE
116 environment variable that may be set.
117
119 This program implements one extension to the standard "hex file" for‐
120 mat. Lines beginning with a "#" character are ignored, and may be used
121 to hold copyright statements and other information. Other tools may
122 not handle hexfiles using this extension.
123 At this writing, "usbfs" is a kernel configuration option. That means
125 that device drivers relying on user mode firmware downloading may need
126 to depend on that kernel configuration option. A less preferable
127 alternative involves compiling the firmware into the kernel and manag‐
128 ing downloads and renumeration there. This is less preferable in part
129 because much device firmware is provided with GPL-incompatible licens‐
130 ing, and in part because storing such firmware firmware wastes kernel
131 memory.
132 For EZ-USB family devices, the hardware's first stage loader (support‐
134 ing the 0xA0 vendor request) can't write into external memory. Config‐
135 urations that put firmware into external memory thus need a second
136 stage loader. For typical "flat" memory architectures, a loader sup‐
137 porting the 0xA3 vendor request is used to write into that memory.
138 Similarly, a second stage loader that supports the 0xA2 vendor request
139 is needed when writing boot firmware into an I2C EEPROM. These 0xA2
140 and 0xA3 vendor commands are conventions defined by Cypress. Devices
141 that use bank switching or similar mechanisms to stretch the 64KByte
142 address space may need different approach to loading firmware.
143 Not all devices support EEPROM updates. Some EZ-USB based devices
145 don't have an I2C EEPROM; many such EEPROMs are too small to store
146 firmware; and some firmware can't be placed in bootable I2C EEPROMs.
147
149 DEVICE normally names a "usbfs" file that will be used to talk to the
150 device. This is provided by the Linux kernel as part of USB
151 hotplugging.
152
154 hotplug(8)
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157 Linux Hotplugging Project http://linux-hotplug.sourceforge.net/
158 April 2002 FXLOAD(8)