On 3/22/22 6:05 PM, Heinrich Schuchardt wrote:
On 3/22/22 21:59, Sean Anderson wrote:
This converts the semihosting readme to rST. I have tried to make only cosmetic changes, but I did fix up the first link (which was broken).
Signed-off-by: Sean Anderson sean.anderson@seco.com
(no changes since v1)
doc/usage/index.rst | 1 + .../semihosting.rst} | 35 +++++++++++-------- 2 files changed, 21 insertions(+), 15 deletions(-) rename doc/{README.semihosting => usage/semihosting.rst} (53%)
diff --git a/doc/usage/index.rst b/doc/usage/index.rst index 750102830b..bfa59f2217 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -11,6 +11,7 @@ Use U-Boot netconsole partitions cmdline + semihosting
Shell commands -------------- diff --git a/doc/README.semihosting b/doc/usage/semihosting.rst similarity index 53% rename from doc/README.semihosting rename to doc/usage/semihosting.rst index f382d0131e..ed16e4d582 100644 --- a/doc/README.semihosting +++ b/doc/usage/semihosting.rst @@ -1,35 +1,40 @@ -SPDX-License-Identifier: GPL-2.0+ -/*
- Copyright 2014 Broadcom Corporation.
- */
+.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright 2014 Broadcom Corporation.
+Semihosting +===========
Semihosting is ARM's way of having a real or virtual target communicate
Thank you for starting the conversion. I think this document needs some rework in a future patch:
Semihosting is not ARM specific. See https://qemu.readthedocs.io/en/latest/system/invocation.html
Ah, I was only aware of the RISC-V version (which is basically ARM but with a different trap instruction). However, for this patch I am trying not to modify the original source of this file too much (except to fix the links and maybe some spelling).
with a host or host debugger for basic operations such as file I/O, -console I/O, etc. Please see -http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0471c/Bgbjjgi... for more information. +console I/O, etc. Please see `Arm's semihosting documentation +https://developer.arm.com/documentation/100863/latest/`_ for more +information.
For developing on armv8 virtual fastmodel platforms, semihosting is a valuable tool since it allows access to image/configuration files before eMMC or other NV media are available.
There are two main ARM virtual Fixed Virtual Platform (FVP) models, -Versatile Express (VE) FVP and BASE FVP (See -http://www.arm.com/products/tools/models/fast-models/foundation-model.php) +`Versatile Express (VE) FVP and BASE FVP +http://www.arm.com/products/tools/models/fast-models/foundation-model.php`_. The initial vexpress64 u-boot board created here runs on the VE virtual platform using the license-free Foundation_v8 simulator. Fortunately, the Foundation_v8 simulator also supports the BASE_FVP model which companies can purchase licenses for and contain much more functionality.
This does not capture the usage of QEMU's semihosting at all.
-So we can, in u-boot, run either model by either using the VE FVP (default), -or turning on CONFIG_BASE_FVP for the more full featured model. +So we can, in U-Boot, run either model by either using the VE FVP (default), +or turning on ``CONFIG_BASE_FVP`` for the more full featured model.
-Rather than create a new armv8 board similar to armltd/vexpress64, add -semihosting calls to the existing one, enabled with CONFIG_SEMIHOSTING -and CONFIG_BASE_FVP both set. Also reuse the existing board config file +Rather than create a new armv8 board similar to ``armltd/vexpress64``, add
%s/create/creating/
This is correct (though clumsy).
+semihosting calls to the existing one, enabled with ``CONFIG_SEMIHOSTING`` +and ``CONFIG_BASE_FVP`` both set. Also reuse the existing board config file vexpress_aemv8.h but differentiate the two models by the presence or -absence of CONFIG_BASE_FVP. This change is tested and works on both the +absence of ``CONFIG_BASE_FVP``. This change is tested and works on both the Foundation and Base fastmodel simulators.
-The semihosting code adds a command: +Loading files +-------------
+The semihosting code adds a "hostfs"::
Do you mean:
"Semihosting provides access to the host file system via the smhload command:"
Yes, that is better, though I think I accidentally changed the wording here when creating this commit.
smhload <image> <address> [env var]
Can this command be removed once you can bind semihosting as a host filesystem (patch 12/29)? It seems duplicate to 'load host'.
Yes. See patch 17/29.
--Sean