From 217e51b9101fb4779c8dc00a562f77c0c9a70afe Mon Sep 17 00:00:00 2001
From: Wenlong Zhang <zhangwenlong@loongson.cn>
Date: Wed, 11 Jan 2023 17:28:18 +0800
Subject: [PATCH] add boost context support for loongarch64 new

---
 boost/predef/architecture.h                   |   1 +
 boost/predef/architecture/loongarch.h         |  39 ++++++
 boost/predef/other/endian.h                   |   1 +
 boostcpp.jam                                  |   5 +-
 libs/config/checks/architecture/Jamfile.jam   |   1 +
 libs/config/checks/architecture/loongarch.cpp |  11 ++
 libs/context/CMakeLists.txt                   |   4 +-
 libs/context/build/Jamfile.v2                 |  13 ++
 libs/context/build/architecture.jam           |   4 +
 libs/context/doc/architectures.qbk            |   1 +
 libs/context/doc/context.xml                  |  27 ++++
 .../doc/html/context/architectures.html       |  27 ++++
 .../src/asm/jump_loongarch64_sysv_elf_gas.S   | 121 ++++++++++++++++++
 .../src/asm/make_loongarch64_sysv_elf_gas.S   |  72 +++++++++++
 .../src/asm/ontop_loongarch64_sysv_elf_gas.S  | 118 +++++++++++++++++
 tools/build/src/engine/jam.h                  |   4 +
 .../tools/features/architecture-feature.jam   |   3 +
 17 files changed, 448 insertions(+), 4 deletions(-)
 create mode 100644 boost/predef/architecture/loongarch.h
 create mode 100644 libs/config/checks/architecture/loongarch.cpp
 create mode 100644 libs/context/src/asm/jump_loongarch64_sysv_elf_gas.S
 create mode 100644 libs/context/src/asm/make_loongarch64_sysv_elf_gas.S
 create mode 100644 libs/context/src/asm/ontop_loongarch64_sysv_elf_gas.S

diff --git a/boost/predef/architecture.h b/boost/predef/architecture.h
index 471c263..55d036f 100644
--- a/boost/predef/architecture.h
+++ b/boost/predef/architecture.h
@@ -17,6 +17,7 @@ http://www.boost.org/LICENSE_1_0.txt)
 #include <boost/predef/architecture/convex.h>
 #include <boost/predef/architecture/e2k.h>
 #include <boost/predef/architecture/ia64.h>
+#include <boost/predef/architecture/loongarch.h>
 #include <boost/predef/architecture/m68k.h>
 #include <boost/predef/architecture/mips.h>
 #include <boost/predef/architecture/parisc.h>
diff --git a/boost/predef/architecture/loongarch.h b/boost/predef/architecture/loongarch.h
new file mode 100644
index 0000000..17015d8
--- /dev/null
+++ b/boost/predef/architecture/loongarch.h
@@ -0,0 +1,39 @@
+/*
+Copyright Zhang Na 2022
+Distributed under the Boost Software License, Version 1.0.
+(See accompanying file LICENSE_1_0.txt or copy at
+http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+#ifndef BOOST_PREDEF_ARCHITECTURE_LOONGARCH_H
+#define BOOST_PREDEF_ARCHITECTURE_LOONGARCH_H
+
+#include <boost/predef/version_number.h>
+#include <boost/predef/make.h>
+
+/* tag::reference[]
+= `BOOST_ARCH_LOONGARCH`
+[options="header"]
+|===
+| {predef_symbol} | {predef_version}
+| `+__loongarch__+` | {predef_detection}
+|===
+*/ // end::reference[]
+
+#define BOOST_ARCH_LOONGARCH BOOST_VERSION_NUMBER_NOT_AVAILABLE
+
+#if defined(__loongarch__)
+#   undef BOOST_ARCH_LOONGARCH
+#   define BOOST_ARCH_LOONGARCH BOOST_VERSION_NUMBER_AVAILABLE
+#endif
+
+#if BOOST_ARCH_LOONGARCH
+#   define BOOST_ARCH_LOONGARCH_AVAILABLE
+#endif
+
+#define BOOST_ARCH_LOONGARCH_NAME "LoongArch"
+
+#endif
+
+#include <boost/predef/detail/test.h>
+BOOST_PREDEF_DECLARE_TEST(BOOST_ARCH_LOONGARCH,BOOST_ARCH_LOONGARCH_NAME)
diff --git a/boost/predef/other/endian.h b/boost/predef/other/endian.h
index d8ec63f..b712673 100644
--- a/boost/predef/other/endian.h
+++ b/boost/predef/other/endian.h
@@ -121,6 +121,7 @@ information and acquired knowledge:
         defined(__ARMEL__) || \
         defined(__THUMBEL__) || \
         defined(__AARCH64EL__) || \
+	defined(__loongarch__) || \
         defined(_MIPSEL) || \
         defined(__MIPSEL) || \
         defined(__MIPSEL__) || \
diff --git a/boostcpp.jam b/boostcpp.jam
index f60e85c..c938b72 100644
--- a/boostcpp.jam
+++ b/boostcpp.jam
@@ -634,7 +634,7 @@ rule address-model ( )
     return <conditional>@boostcpp.deduce-address-model ;
 }

-local deducable-architectures = sw_64 arm mips1 power riscv s390x sparc x86 combined ;
+local deducable-architectures = sw_64 arm loongarch mips1 power riscv s390x sparc x86 combined ;
 feature.feature deduced-architecture : $(deducable-architectures) : propagated optional composite hidden ;
 for a in $(deducable-architectures)
 {
@@ -645,10 +645,11 @@ rule deduce-architecture ( properties * )
 {
     local result ;
     local filtered = [ toolset-properties $(properties) ] ;
-    local names = arm sw_64 mips1 power riscv s390x sparc x86 combined ;
+    local names = arm sw_64 loongarch mips1 power riscv s390x sparc x86 combined ;
     local idx = [ configure.find-builds "default architecture" : $(filtered)
         : /boost/architecture//arm
         : /boost/architecture//sw_64
+        : /boost/architecture//loongarch
         : /boost/architecture//mips1
         : /boost/architecture//power
         : /boost/architecture//riscv
diff --git a/libs/config/checks/architecture/Jamfile.jam b/libs/config/checks/architecture/Jamfile.jam
index f86c732..ee260ff 100644
--- a/libs/config/checks/architecture/Jamfile.jam
+++ b/libs/config/checks/architecture/Jamfile.jam
@@ -19,6 +19,7 @@ obj 64 : 64.cpp ;
 obj arm      : arm.cpp ;
 obj sw_64    : sw_64.cpp ;
 obj combined : combined.cpp ;
+obj loongarch : loongarch.cpp ;
 obj mips1    : mips1.cpp ;
 obj power    : power.cpp ;
 obj riscv    : riscv.cpp ;
diff --git a/libs/config/checks/architecture/loongarch.cpp b/libs/config/checks/architecture/loongarch.cpp
new file mode 100644
index 0000000..5be8cb0
--- /dev/null
+++ b/libs/config/checks/architecture/loongarch.cpp
@@ -0,0 +1,11 @@
+// loongarch.cpp
+//
+// Copyright (c) 2012 Steven Watanabe
+//
+// Distributed under the Boost Software License Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#if !defined(__loongarch__)
+#error "Not LoongArch"
+#endif
diff --git a/libs/context/CMakeLists.txt b/libs/context/CMakeLists.txt
index 99c11b2..f301143 100644
--- a/libs/context/CMakeLists.txt
+++ b/libs/context/CMakeLists.txt
@@ -48,7 +48,7 @@ unset(_default_abi)

 ## Arch-and-model

-set(_all_archs arm arm64 sw_64 mips32 mips64 ppc32 ppc64 riscv64 s390x i386 x86_64 combined)
+set(_all_archs arm arm64 loongarch64 sw_64 mips32 mips64 ppc32 ppc64 riscv64 s390x i386 x86_64 combined)

 # Try at start to auto determine arch from CMake.
 if(CMAKE_SYSTEM_PROCESSOR IN_LIST _all_archs)
@@ -74,7 +74,7 @@ else()
   endif()
 endif()

-set(BOOST_CONTEXT_ARCHITECTURE "${_default_arch}" CACHE STRING "Boost.Context architecture (arm, arm64, mips32, sw_64,  mips64, ppc32, ppc64, riscv64, s390x, i386, x86_64, combined)")
+set(BOOST_CONTEXT_ARCHITECTURE "${_default_arch}" CACHE STRING "Boost.Context architecture (arm, arm64, loongarch64, mips32, sw_64,  mips64, ppc32, ppc64, riscv64, s390x, i386, x86_64, combined)")
 set_property(CACHE BOOST_CONTEXT_ARCHITECTURE PROPERTY STRINGS ${_all_archs})

 unset(_all_archs)
diff --git a/libs/context/build/Jamfile.v2 b/libs/context/build/Jamfile.v2
index 30e9598..6238510 100644
--- a/libs/context/build/Jamfile.v2
+++ b/libs/context/build/Jamfile.v2
@@ -254,6 +254,19 @@ alias asm_sources
      <toolset>darwin
    ;

+# LOONGARCH64
+# LOONGARCH64/SYSV/ELF
+alias asm_sources
+   : asm/make_loongarch64_sysv_elf_gas.S
+     asm/jump_loongarch64_sysv_elf_gas.S
+     asm/ontop_loongarch64_sysv_elf_gas.S
+   : <abi>sysv
+     <address-model>64
+     <architecture>loongarch
+     <binary-format>elf
+     <toolset>gcc
+   ;
+
 # MIPS
 # MIPS32/O32/ELF
 alias asm_sources
diff --git a/libs/context/build/architecture.jam b/libs/context/build/architecture.jam
index 4c7d211..78820cd 100644
--- a/libs/context/build/architecture.jam
+++ b/libs/context/build/architecture.jam
@@ -59,6 +59,10 @@ rule deduce-architecture ( properties * )
         {
             return <architecture>sw_64 ;
         }
+        else if [ configure.builds /boost/architecture//loongarch : $(properties) : loongarch ]
+        {
+            return <architecture>loongarch ;
+        }
         else if [ configure.builds /boost/architecture//mips : $(properties) : mips ]
         {
             return <architecture>mips ;
diff --git a/libs/context/doc/architectures.qbk b/libs/context/doc/architectures.qbk
index 4be823c..76d6d58 100644
--- a/libs/context/doc/architectures.qbk
+++ b/libs/context/doc/architectures.qbk
@@ -15,6 +15,7 @@ architectures:
     [[arm (aarch32)] [AAPCS|ELF]      [AAPCS|PE] [-]            [AAPCS|MACH-O]]
     [[arm (aarch64)] [AAPCS|ELF]      [-]        [AAPCS|MACH-O] [AAPCS|MACH-O]]
     [[i386]          [SYSV|ELF]       [MS|PE]    [SYSV|MACH-O]  [-]]
+    [[loongarch64]   [SYSV|ELF]       [-]        [-]            [-]]
     [[mips]          [O32|N64|ELF]    [-]        [-]            [-]]
     [[ppc32]         [SYSV|ELF|XCOFF] [-]        [SYSV|MACH-O]  [-]]
     [[ppc64]         [SYSV|ELF|XCOFF] [-]        [SYSV|MACH-O]  [-]]
diff --git a/libs/context/doc/context.xml b/libs/context/doc/context.xml
index d83439d..ef920cd 100644
--- a/libs/context/doc/context.xml
+++ b/libs/context/doc/context.xml
@@ -3379,6 +3379,33 @@
               </para>
             </entry>
           </row>
+          <row>
+            <entry>
+              <para>
+                loongarch64
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|ELF
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+          </row>
           <row>
             <entry>
               <para>
diff --git a/libs/context/doc/html/context/architectures.html b/libs/context/doc/html/context/architectures.html
index 416627d..29bd803 100644
--- a/libs/context/doc/html/context/architectures.html
+++ b/libs/context/doc/html/context/architectures.html
@@ -151,6 +151,33 @@
             </td>
 </tr>
 <tr>
+<td>
+              <p>
+                loongarch64
+              </p>
+            </td>
+<td>
+              <p>
+                SYSV|ELF
+              </p>
+            </td>
+<td>
+              <p>
+                -
+              </p>
+            </td>
+<td>
+              <p>
+                -
+              </p>
+            </td>
+<td>
+              <p>
+                -
+              </p>
+            </td>
+</tr>
+<tr>
 <td>
               <p>
                 mips
diff --git a/libs/context/src/asm/jump_loongarch64_sysv_elf_gas.S b/libs/context/src/asm/jump_loongarch64_sysv_elf_gas.S
new file mode 100644
index 0000000..74c081e
--- /dev/null
+++ b/libs/context/src/asm/jump_loongarch64_sysv_elf_gas.S
@@ -0,0 +1,121 @@
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |     0     |     8     |    16     |     24    |  *
+ *  -------------------------------------------------  *
+ *  |    FS0    |    FS1    |    FS2    |    FS3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |     32    |    40     |     48    |     56    |  *
+ *  -------------------------------------------------  *
+ *  |    FS4    |    FS5    |    FS6    |    FS7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |     64    |    72     |     80    |     88    |  *
+ *  -------------------------------------------------  *
+ *  |    S0     |    S1     |     S2    |     S3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    S4     |    S5     |     S6    |     S7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    S8     |    FP     |     RA    |     PC    |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "jump_loongarch64_sysv_elf_gas.S"
+.text
+.globl jump_fcontext
+.align 2
+.type jump_fcontext,@function
+jump_fcontext:
+    # reserve space on stack
+    addi.d  $sp, $sp, -160
+
+    # save fs0 - fs7
+    fst.d  $fs0, $sp, 0
+    fst.d  $fs1, $sp, 8
+    fst.d  $fs2, $sp, 16
+    fst.d  $fs3, $sp, 24
+    fst.d  $fs4, $sp, 32
+    fst.d  $fs5, $sp, 40
+    fst.d  $fs6, $sp, 48
+    fst.d  $fs7, $sp, 56
+
+    # save s0 - s8, fp, ra
+    st.d  $s0, $sp, 64
+    st.d  $s1, $sp, 72
+    st.d  $s2, $sp, 80
+    st.d  $s3, $sp, 88
+    st.d  $s4, $sp, 96
+    st.d  $s5, $sp, 104
+    st.d  $s6, $sp, 112
+    st.d  $s7, $sp, 120
+    st.d  $s8, $sp, 128
+    st.d  $fp, $sp, 136
+    st.d  $ra, $sp, 144
+
+    # save RA as PC
+    st.d  $ra, $sp, 152
+
+    # store SP (pointing to context-data) in A2
+    move  $a2, $sp
+
+    # restore SP (pointing to context-data) from A0
+    move  $sp, $a0
+
+    # load fs0 - fs7
+    fld.d  $fs0, $sp, 0
+    fld.d  $fs1, $sp, 8
+    fld.d  $fs2, $sp, 16
+    fld.d  $fs3, $sp, 24
+    fld.d  $fs4, $sp, 32
+    fld.d  $fs5, $sp, 40
+    fld.d  $fs6, $sp, 48
+    fld.d  $fs7, $sp, 56
+
+    #load s0 - s7
+    ld.d  $s0, $sp, 64
+    ld.d  $s1, $sp, 72
+    ld.d  $s2, $sp, 80
+    ld.d  $s3, $sp, 88
+    ld.d  $s4, $sp, 96
+    ld.d  $s5, $sp, 104
+    ld.d  $s6, $sp, 112
+    ld.d  $s7, $sp, 120
+    ld.d  $s8, $sp, 128
+    ld.d  $fp, $sp, 136
+    ld.d  $ra, $sp, 144
+
+    # return transfer_t from jump
+    # pass transfer_t as first arg in context function
+    # a0 == FCTX, a1 == DATA
+    move  $a0, $a2
+
+    # load PC
+    ld.d  $a2, $sp, 152
+
+    # restore stack
+    addi.d  $sp, $sp, 160
+
+    # jump to context
+    jr  $a2
+.size jump_fcontext, .-jump_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/libs/context/src/asm/make_loongarch64_sysv_elf_gas.S b/libs/context/src/asm/make_loongarch64_sysv_elf_gas.S
new file mode 100644
index 0000000..5506270
--- /dev/null
+++ b/libs/context/src/asm/make_loongarch64_sysv_elf_gas.S
@@ -0,0 +1,72 @@
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |     0     |     8     |    16     |     24    |  *
+ *  -------------------------------------------------  *
+ *  |    FS0    |    FS1    |    FS2    |    FS3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |     32    |    40     |     48    |     56    |  *
+ *  -------------------------------------------------  *
+ *  |    FS4    |    FS5    |    FS6    |    FS7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |     64    |    72     |     80    |     88    |  *
+ *  -------------------------------------------------  *
+ *  |    S0     |    S1     |     S2    |     S3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    S4     |    S5     |     S6    |     S7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    S8     |    FP     |     RA    |     PC    |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "make_loongarch64_sysv_elf_gas.S"
+.text
+.globl make_fcontext
+.align 2
+.type make_fcontext,@function
+make_fcontext:
+    # shift address in A0 to lower 16 byte boundary
+    bstrins.d $a0, $zero, 3, 0
+
+    # reserve space for context-data on context-stack
+    addi.d  $a0, $a0, -160
+
+    # third arg of make_fcontext() == address of context-function
+    st.d  $a2, $a0, 152
+
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    la.local  $a4, finish
+    st.d  $a4, $a0, 144
+
+    # return pointer to context-data
+    jr  $ra
+
+finish:
+    # exit code is zero
+    li.d  $a0, 0
+    # call _exit(0)
+    b  %plt(_exit)
+
+.size make_fcontext, .-make_fcontext
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/libs/context/src/asm/ontop_loongarch64_sysv_elf_gas.S b/libs/context/src/asm/ontop_loongarch64_sysv_elf_gas.S
new file mode 100644
index 0000000..c6ea044
--- /dev/null
+++ b/libs/context/src/asm/ontop_loongarch64_sysv_elf_gas.S
@@ -0,0 +1,118 @@
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |     0     |     8     |    16     |     24    |  *
+ *  -------------------------------------------------  *
+ *  |    FS0    |    FS1    |    FS2    |    FS3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |     32    |    40     |     48    |     56    |  *
+ *  -------------------------------------------------  *
+ *  |    FS4    |    FS5    |    FS6    |    FS7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |     64    |    72     |     80    |     88    |  *
+ *  -------------------------------------------------  *
+ *  |    S0     |    S1     |     S2    |     S3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    S4     |    S5     |     S6    |     S7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    S8     |    FP     |     RA    |     PC    |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "ontop_loongarch64_sysv_elf_gas.S"
+.text
+.globl ontop_fcontext
+.align 2
+.type ontop_fcontext,@function
+ontop_fcontext:
+    # reserve space on stack
+    addi.d  $sp, $sp, -160
+
+    # save fs0 - fs7
+    fst.d  $fs0, $sp, 0
+    fst.d  $fs1, $sp, 8
+    fst.d  $fs2, $sp, 16
+    fst.d  $fs3, $sp, 24
+    fst.d  $fs4, $sp, 32
+    fst.d  $fs5, $sp, 40
+    fst.d  $fs6, $sp, 48
+    fst.d  $fs7, $sp, 56
+
+    # save s0 - s8, fp, ra
+    st.d  $s0, $sp, 64
+    st.d  $s1, $sp, 72
+    st.d  $s2, $sp, 80
+    st.d  $s3, $sp, 88
+    st.d  $s4, $sp, 96
+    st.d  $s5, $sp, 104
+    st.d  $s6, $sp, 112
+    st.d  $s7, $sp, 120
+    st.d  $s8, $sp, 128
+    st.d  $fp, $sp, 136
+    st.d  $ra, $sp, 144
+
+    # save RA as PC
+    st.d  $ra, $sp, 152
+
+    # store SP (pointing to context-data) in A3
+    move  $a3, $sp
+
+    # restore SP (pointing to context-data) from A0
+    move  $sp, $a0
+
+    # load fs0 - fs11
+    fld.d  $fs0, $sp, 0
+    fld.d  $fs1, $sp, 8
+    fld.d  $fs2, $sp, 16
+    fld.d  $fs3, $sp, 24
+    fld.d  $fs4, $sp, 32
+    fld.d  $fs5, $sp, 40
+    fld.d  $fs6, $sp, 48
+    fld.d  $fs7, $sp, 56
+
+    #load s0 - s11, fp, ra
+    ld.d  $s0, $sp, 64
+    ld.d  $s1, $sp, 72
+    ld.d  $s2, $sp, 80
+    ld.d  $s3, $sp, 88
+    ld.d  $s4, $sp, 96
+    ld.d  $s5, $sp, 104
+    ld.d  $s6, $sp, 112
+    ld.d  $s7, $sp, 120
+    ld.d  $s8, $sp, 128
+    ld.d  $fp, $sp, 136
+    ld.d  $ra, $sp, 144
+
+    # return transfer_t from jump
+    # pass transfer_t as first arg in context function
+    # a0 == FCTX, a1 == DATA
+    move  $a0, $a3
+
+    # adjust stack
+    addi.d  $sp, $sp, 160
+
+    # jump to context
+    jr  $a2
+.size ontop_fcontext, .-ontop_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/tools/build/src/engine/jam.h b/tools/build/src/engine/jam.h
index 59e5f82..76a7869 100644
--- a/tools/build/src/engine/jam.h
+++ b/tools/build/src/engine/jam.h
@@ -446,6 +446,10 @@
     #define OSPLAT "OSPLAT=PARISC"
 #endif

+#ifdef __loongarch64
+    #define OSPLAT "OSPLAT=LOONGARCH64"
+#endif
+
 #ifndef OSPLAT
     #define OSPLAT ""
 #endif
diff --git a/tools/build/src/tools/features/architecture-feature.jam b/tools/build/src/tools/features/architecture-feature.jam
index e320307..124b4be 100644
--- a/tools/build/src/tools/features/architecture-feature.jam
+++ b/tools/build/src/tools/features/architecture-feature.jam
@@ -45,6 +45,9 @@ feature.feature architecture
         # RISC-V
         riscv

+       # loongarch
+       loongarch
+
         # z Systems (aka s390x)
         s390x
     :
--
2.33.0