From 878d1e8704f0d0387379598aa222d7d7fab86d6b Mon Sep 17 00:00:00 2001 From: Peter Marheine Date: Fri, 25 Mar 2022 04:05:35 +0000 Subject: flashrom.8.tmpl: document realtek_mst_i2c_spi This programmer was undocumented. Signed-off-by: Peter Marheine Change-Id: Idde5a8de014fe84c4a472f8fbfd3562350997d39 Reviewed-on: https://review.coreboot.org/c/flashrom/+/63103 Tested-by: build bot (Jenkins) Reviewed-by: Edward O'Callaghan Reviewed-by: Nikolai Artemiev --- flashrom.8.tmpl | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/flashrom.8.tmpl b/flashrom.8.tmpl index 3e4bc5e4..92dff68f 100644 --- a/flashrom.8.tmpl +++ b/flashrom.8.tmpl @@ -393,6 +393,8 @@ bitbanging adapter) .sp .BR "* stlinkv3_spi" " (for SPI flash ROMs attached to STMicroelectronics STLINK V3 devices)" .sp +.BR "* realtek_mst_i2c_spi" " (for SPI flash ROMs attached to Realtek DisplayPort hubs accessible through I2C)" +.sp Some programmers have optional or mandatory parameters which are described in detail in the .B PROGRAMMER-SPECIFIC INFORMATION @@ -1415,6 +1417,46 @@ syntax where \fBfrequency\fP is the SPI clock frequency in kHz. If the passed frequency is not supported by the adapter the nearest lower supported frequency will be used. .SS +.BR "realtek_mst_i2c_spi " programmer +.IP +This programmer supports SPI flash programming for chips attached to Realtek +DisplayPort MST hubs, themselves accessed through I2C (tunneling SPI flash +commands through the MST hub's I2C connection with the host). + +The I2C bus on which the hub is reachable must be specified by either a device +path with the \fBdevpath\fP option: +.sp +.B " flashrom \-p realtek_mst_i2c_spi:devpath=/dev/i2c-8" +.sp +or by a bus number with the \fBbus\fP option, which implies a device path like +/dev/i2c-N where N is the specified bus number: +.sp +.B " flashrom \-p realtek_mst_i2c_spi:bus=8" +.TP +.B In-system programming (ISP) mode +.sp +The \fBreset-mcu\fP and \fBenter-isp\fP options provide control over device +mode changes, where each can be set to 0 or 1 to enable or disable the +corresponding mode transition. + +\fBenter-isp\fP defaults to 1, and if enabled will issue commands to the MST +hub when beginning operation to put it into ISP mode. + +\fBreset-mcu\fP defaults to 0, and if enabled will issue a reset command to +the MST hub on programming completion, causing it to exit ISP mode and to +reload its own firmware from flash. + +The hub must be in ISP mode for SPI flash access to be possible, so it is +usually only useful to disable \fBenter-isp\fP if an earlier invocation avoided +resetting it on completion. For instance, to erase the flash and +rewrite it with the contents of a file without resetting in between (which +could render it nonfunctional if attempting to load firmware from a blank +flash): +.sp +.B " flashrom -p realtek_mst_i2c_spi:bus=0,enter-isp=1,reset-mcu=0 -E" +.br +.B " flashrom -p realtek_mst_i2c_spi:bus=0,enter-isp=0,reset-mcu=1 -w new.bin" +.sp .SH EXAMPLES To back up and update your BIOS, run @@ -1493,6 +1535,9 @@ permissions are set. .B ogp needs PCI configuration space read access and raw memory access. .sp +.B realtek_mst_i2c_spi +needs userspace access to the selected I2C bus. +.sp On OpenBSD, you can obtain raw access permission by setting .B "securelevel=-1" in -- cgit v1.2.3