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authorJonathan Corbet <corbet@lwn.net>2023-03-23 23:30:24 +0300
committerJonathan Corbet <corbet@lwn.net>2023-03-30 22:00:35 +0300
commit0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b (patch)
tree6a0b03f29021f29544e19a07ae3ef9dee53301ea /Documentation/arch
parentd47a97bd38a3ac295ff8a23b979ef1f9a9fc36e7 (diff)
downloadlinux-0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b.tar.xz
docs: move openrisc documentation under Documentation/arch/
Architecture-specific documentation is being moved into Documentation/arch/ as a way of cleaning up the top-level documentation directory and making the docs hierarchy more closely match the source hierarchy. Move Documentation/openrisc into arch/ and fix all in-tree references. Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Acked-by: Alex Shi <alexs@kernel.org> Reviewed-by: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/arch')
-rw-r--r--Documentation/arch/index.rst2
-rw-r--r--Documentation/arch/openrisc/features.rst3
-rw-r--r--Documentation/arch/openrisc/index.rst20
-rw-r--r--Documentation/arch/openrisc/openrisc_port.rst121
-rw-r--r--Documentation/arch/openrisc/todo.rst15
5 files changed, 160 insertions, 1 deletions
diff --git a/Documentation/arch/index.rst b/Documentation/arch/index.rst
index 792f58e30f25..65945daa40fe 100644
--- a/Documentation/arch/index.rst
+++ b/Documentation/arch/index.rst
@@ -17,7 +17,7 @@ implementation.
../m68k/index
../mips/index
../nios2/index
- ../openrisc/index
+ openrisc/index
../parisc/index
../powerpc/index
../riscv/index
diff --git a/Documentation/arch/openrisc/features.rst b/Documentation/arch/openrisc/features.rst
new file mode 100644
index 000000000000..3f7c40d219f2
--- /dev/null
+++ b/Documentation/arch/openrisc/features.rst
@@ -0,0 +1,3 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. kernel-feat:: $srctree/Documentation/features openrisc
diff --git a/Documentation/arch/openrisc/index.rst b/Documentation/arch/openrisc/index.rst
new file mode 100644
index 000000000000..6879f998b87a
--- /dev/null
+++ b/Documentation/arch/openrisc/index.rst
@@ -0,0 +1,20 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+OpenRISC Architecture
+=====================
+
+.. toctree::
+ :maxdepth: 2
+
+ openrisc_port
+ todo
+
+ features
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
diff --git a/Documentation/arch/openrisc/openrisc_port.rst b/Documentation/arch/openrisc/openrisc_port.rst
new file mode 100644
index 000000000000..657ac4af7be6
--- /dev/null
+++ b/Documentation/arch/openrisc/openrisc_port.rst
@@ -0,0 +1,121 @@
+==============
+OpenRISC Linux
+==============
+
+This is a port of Linux to the OpenRISC class of microprocessors; the initial
+target architecture, specifically, is the 32-bit OpenRISC 1000 family (or1k).
+
+For information about OpenRISC processors and ongoing development:
+
+ ======= =============================
+ website https://openrisc.io
+ email openrisc@lists.librecores.org
+ ======= =============================
+
+---------------------------------------------------------------------
+
+Build instructions for OpenRISC toolchain and Linux
+===================================================
+
+In order to build and run Linux for OpenRISC, you'll need at least a basic
+toolchain and, perhaps, the architectural simulator. Steps to get these bits
+in place are outlined here.
+
+1) Toolchain
+
+Toolchain binaries can be obtained from openrisc.io or our github releases page.
+Instructions for building the different toolchains can be found on openrisc.io
+or Stafford's toolchain build and release scripts.
+
+ ========== =================================================
+ binaries https://github.com/openrisc/or1k-gcc/releases
+ toolchains https://openrisc.io/software
+ building https://github.com/stffrdhrn/or1k-toolchain-build
+ ========== =================================================
+
+2) Building
+
+Build the Linux kernel as usual::
+
+ make ARCH=openrisc CROSS_COMPILE="or1k-linux-" defconfig
+ make ARCH=openrisc CROSS_COMPILE="or1k-linux-"
+
+3) Running on FPGA (optional)
+
+The OpenRISC community typically uses FuseSoC to manage building and programming
+an SoC into an FPGA. The below is an example of programming a De0 Nano
+development board with the OpenRISC SoC. During the build FPGA RTL is code
+downloaded from the FuseSoC IP cores repository and built using the FPGA vendor
+tools. Binaries are loaded onto the board with openocd.
+
+::
+
+ git clone https://github.com/olofk/fusesoc
+ cd fusesoc
+ sudo pip install -e .
+
+ fusesoc init
+ fusesoc build de0_nano
+ fusesoc pgm de0_nano
+
+ openocd -f interface/altera-usb-blaster.cfg \
+ -f board/or1k_generic.cfg
+
+ telnet localhost 4444
+ > init
+ > halt; load_image vmlinux ; reset
+
+4) Running on a Simulator (optional)
+
+QEMU is a processor emulator which we recommend for simulating the OpenRISC
+platform. Please follow the OpenRISC instructions on the QEMU website to get
+Linux running on QEMU. You can build QEMU yourself, but your Linux distribution
+likely provides binary packages to support OpenRISC.
+
+ ============= ======================================================
+ qemu openrisc https://wiki.qemu.org/Documentation/Platforms/OpenRISC
+ ============= ======================================================
+
+---------------------------------------------------------------------
+
+Terminology
+===========
+
+In the code, the following particles are used on symbols to limit the scope
+to more or less specific processor implementations:
+
+========= =======================================
+openrisc: the OpenRISC class of processors
+or1k: the OpenRISC 1000 family of processors
+or1200: the OpenRISC 1200 processor
+========= =======================================
+
+---------------------------------------------------------------------
+
+History
+========
+
+18-11-2003 Matjaz Breskvar (phoenix@bsemi.com)
+ initial port of linux to OpenRISC/or32 architecture.
+ all the core stuff is implemented and seams usable.
+
+08-12-2003 Matjaz Breskvar (phoenix@bsemi.com)
+ complete change of TLB miss handling.
+ rewrite of exceptions handling.
+ fully functional sash-3.6 in default initrd.
+ a much improved version with changes all around.
+
+10-04-2004 Matjaz Breskvar (phoenix@bsemi.com)
+ alot of bugfixes all over.
+ ethernet support, functional http and telnet servers.
+ running many standard linux apps.
+
+26-06-2004 Matjaz Breskvar (phoenix@bsemi.com)
+ port to 2.6.x
+
+30-11-2004 Matjaz Breskvar (phoenix@bsemi.com)
+ lots of bugfixes and enhancments.
+ added opencores framebuffer driver.
+
+09-10-2010 Jonas Bonn (jonas@southpole.se)
+ major rewrite to bring up to par with upstream Linux 2.6.36
diff --git a/Documentation/arch/openrisc/todo.rst b/Documentation/arch/openrisc/todo.rst
new file mode 100644
index 000000000000..420b18b87eda
--- /dev/null
+++ b/Documentation/arch/openrisc/todo.rst
@@ -0,0 +1,15 @@
+====
+TODO
+====
+
+The OpenRISC Linux port is fully functional and has been tracking upstream
+since 2.6.35. There are, however, remaining items to be completed within
+the coming months. Here's a list of known-to-be-less-than-stellar items
+that are due for investigation shortly, i.e. our TODO list:
+
+- Implement the rest of the DMA API... dma_map_sg, etc.
+
+- Finish the renaming cleanup... there are references to or32 in the code
+ which was an older name for the architecture. The name we've settled on is
+ or1k and this change is slowly trickling through the stack. For the time
+ being, or32 is equivalent to or1k.