[PATCH v11 01/26] target/loongarch: Add README

[Song Gao]

This patch gives an introduction to the LoongArch target.

Signed-off-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 MAINTAINERS             |  5 ++++
 target/loongarch/README | 76 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+)
 create mode 100644 target/loongarch/README

diff --git a/MAINTAINERS b/MAINTAINERS
index d3879aa..935bbce 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -213,6 +213,11 @@ S: Maintained
 F: target/hppa/
 F: disas/hppa.c
 
+LoongArch TCG CPUS
+M: Song Gao <gaosong@loongson.cn>
+S: Maintained
+F: target/loongarch/
+
 M68K TCG CPUs
 M: Laurent Vivier <laurent@vivier.eu>
 S: Maintained
diff --git a/target/loongarch/README b/target/loongarch/README
new file mode 100644
index 0000000..09f809c
--- /dev/null
+++ b/target/loongarch/README
@@ -0,0 +1,76 @@
+- Introduction
+
+  LoongArch is the general processor architecture of Loongson.
+
+  The following versions of the LoongArch core are supported
+    core: 3A5000
+    
https://github.com/loongson/LoongArch-Documentation/releases/download/2021.08.17/LoongArch-Vol1-v1.00-EN.pdf
+
+  We can get the latest loongarch documents at 
https://github.com/loongson/LoongArch-Documentation/tags.
+
+
+- Linux-user emulation
+
+  We already support Linux user emulation. We can use LoongArch cross-tools to 
build LoongArch executables on X86 machines,
+  and We can also use qemu-loongarch64 to run LoongArch executables.
+
+  1. Install LoongArch cross-tools on X86 machines.
+
+    Download cross-tools.
+
+      wget 
https://github.com/loongson/build-tools/releases/latest/download/loongarch64-clfs-20210831-cross-tools.tar.xz
+
+      tar -vxf loongarch64-clfs-20210831-cross-tools.tar.xz -C /opt
+
+    Config cross-tools env.
+
+      . setenv.sh
+
+      setenv.sh:
+
+          #!/bin/sh
+          set -x
+          CC_PREFIX=/opt/cross-tools
+
+          export PATH=$CC_PREFIX/bin:$PATH
+          export LD_LIBRARY_PATH=$CC_PREFIX/lib:$LD_LIBRARY_PATH
+          export 
LD_LIBRARY_PATH=$CC_PREFIX/loongarch64-unknown-linux-gnu/lib/:$LD_LIBRARY_PATH
+          set +x
+
+  2. Test tests/tcg/multiarch.
+
+    ./configure --disable-rdma --disable-pvrdma --prefix=/usr  \
+            --target-list="loongarch64-linux-user"  \
+            --disable-libiscsi --disable-libnfs --disable-libpmem \
+            --disable-glusterfs --enable-libusb --enable-usb-redir \
+            --disable-opengl --disable-xen --enable-spice --disable-werror \
+            --enable-debug --disable-capstone --disable-kvm --enable-profiler
+
+    cd  build/
+
+    make && make check-tcg
+
+  3. Run LoongArch system basic command with loongarch-clfs-system.
+
+    Download clfs-system.
+
+      wget 
https://github.com/loongson/build-tools/releases/latest/download/loongarch64-clfs-system-2021-08-31.tar.bz2
+
+      tar -vxf loongarch64-clfs-system-2021-08-31.tar.bz2 -C /opt/clfs
+
+    Config env.
+
+      cp /opt/clfs/lib64/ld-linux-loongarch64.so.1   /lib64
+
+      export LD_LIBRARY_PATH="/opt/clfs/lib64"
+
+    Run LoongArch system basic command.
+
+      ./qemu-loongarch64  /opt/clfs/usr/bin/bash
+      ./qemu-loongarch64  /opt/clfs/usr/bin/ls
+      ./qemu-loongarch64  /opt/clfs/usr/bin/pwd
+      ...
+
+
+- Note.
+  We can get the latest LoongArch documents or LoongArch tools at 
https://github.com/loongson/
-- 
1.8.3.1