diff --git a/tests/asm/include/common.S b/tests/asm/include/common.S
index 25622de..3275877 100644
--- a/tests/asm/include/common.S
+++ b/tests/asm/include/common.S
@@ -5,6 +5,7 @@
 #define NR_write     4
 #define NR_rt_sigaction 174
 #define NR_rt_sigreturn 173
+#define NR_access_hw_stacks 254
 
 #define SCRATCH_REG0 %g23
 #define SCRATCH_REG1 %g22
@@ -165,6 +166,38 @@
         }
     .endm
 
+#define READ_CHAIN_STACK            0
+#define READ_PROCEDURE_STACK        1
+#define WRITE_PROCEDURE_STACK       2
+#define GET_CHAIN_STACK_OFFSET      3
+#define GET_CHAIN_STACK_SIZE        4
+#define GET_PROCEDURE_STACK_SIZE    5
+#define READ_CHAIN_STACK_EX         6
+#define READ_PROCEDURE_STACK_EX     7
+#define WRITE_PROCEDURE_STACK_EX    8
+#define WRITE_CHAIN_STACK_EX        9
+
+    .macro sys_access_hw_stacks mode, frame_addr=0, buf_addr=0, buf_size=0, size_addr=0
+    {
+        setwd wsz=8, nfx=1
+        sdisp %ctpr1, 0x3
+    }
+    {
+        addd,0 0, NR_access_hw_stacks, %r8
+        addd,1 0, \mode, %r9
+    }
+    {
+        nop 2
+        addd,0 0, \frame_addr, %r10
+        addd,1 0, \buf_addr, %r11
+    }
+    {
+        addd,0 0, \buf_size, %r12
+        addd,1 0, \size_addr, %r13
+        call %ctpr1, wbs=4
+    }
+    .endm
+
 #define assert_(PRED, MSG) \
             ibranch local(ok) ? PRED; \
             write("assert at " __FILE__ ":" str(__LINE__) ":\n" \
@@ -225,8 +258,11 @@
             set_exit_code 1; \
     local(ok):
 
-#define assert_ne_i32(LEFT, RIGHT, MSG) assert_ne(cmpesb, LEFT, RIGHT, MSG)
-#define assert_ne_i64(LEFT, RIGHT, MSG) assert_ne(cmpedb, LEFT, RIGHT, MSG)
+#define assert_ne_i32(LEFT, RIGHT) assert_ne(cmpesb, LEFT, RIGHT, "")
+#define assert_ne_i64(LEFT, RIGHT) assert_ne(cmpedb, LEFT, RIGHT, "")
+
+#define assert_ne_i32m(LEFT, RIGHT, MSG) assert_ne(cmpesb, LEFT, RIGHT, MSG)
+#define assert_ne_i64m(LEFT, RIGHT, MSG) assert_ne(cmpedb, LEFT, RIGHT, MSG)
 
 #define test_helper(OP, CMP, S1, S2, EXPECTED) \
         { \
diff --git a/tests/asm/meson.build b/tests/asm/meson.build
index fef21d4..d48d10a 100644
--- a/tests/asm/meson.build
+++ b/tests/asm/meson.build
@@ -164,6 +164,14 @@ asm_tests = {
     'dam-1': {},
     'dam-2': {},
   },
+  'syscall': {
+    'get-ps-size-1': {},
+    'get-pcs-size-1': {},
+    'get-pcs-offset-1': {},
+    'read-ps-ex-1': {},
+    'read-ps-ex-unaligned-1': { 'should_fail': true },
+    'write-ps-ex-1': {},
+  },
 }
 
 foreach suite, tests : asm_tests
diff --git a/tests/asm/syscall/get-pcs-offset-1.S b/tests/asm/syscall/get-pcs-offset-1.S
new file mode 100644
index 0000000..eb96a36
--- /dev/null
+++ b/tests/asm/syscall/get-pcs-offset-1.S
@@ -0,0 +1,22 @@
+#include "test_start.S"
+
+        setwd wsz=8, nfx=1
+        rrd,0 %pcsp.lo, %g16
+        rrd,0 %pcsp.hi, %g17
+    {
+        andd,0 %g16, (1ULL << 48) - 1, %g16
+        andd,1 %g17, (1ULL << 32) - 1, %g17
+    }
+        addd,0 %g16, %g17, %g16
+        std,2 %g16, [ frame ]
+        sys_access_hw_stacks GET_CHAIN_STACK_OFFSET, frame, 0, 0, offset
+        assert_eq_i64(%r8, 0)
+
+#include "test_end.S"
+
+    .data
+    .balign 8
+frame:
+    .quad 0
+offset:
+    .quad 0
diff --git a/tests/asm/syscall/get-pcs-size-1.S b/tests/asm/syscall/get-pcs-size-1.S
new file mode 100644
index 0000000..5cdf431
--- /dev/null
+++ b/tests/asm/syscall/get-pcs-size-1.S
@@ -0,0 +1,15 @@
+#include "test_start.S"
+
+        setwd wsz=8, nfx=1
+        sys_access_hw_stacks GET_CHAIN_STACK_SIZE, 0, 0, 0, size
+        assert_eq_i64(%r8, 0)
+        ldd,0 [ size ], %g16
+        assert_ne_i64(%g16, 0)
+
+#include "test_end.S"
+
+    .data
+    .balign 8
+    .byte 0
+size:
+    .quad 0
diff --git a/tests/asm/syscall/get-ps-size-1.S b/tests/asm/syscall/get-ps-size-1.S
new file mode 100644
index 0000000..61b0192
--- /dev/null
+++ b/tests/asm/syscall/get-ps-size-1.S
@@ -0,0 +1,15 @@
+#include "test_start.S"
+
+        setwd wsz=8, nfx=1
+        sys_access_hw_stacks GET_PROCEDURE_STACK_SIZE, 0, 0, 0, size
+        assert_eq_i64(%r8, 0)
+        ldd,0 [ size ], %g16
+        assert_ne_i64(%g16, 0)
+
+#include "test_end.S"
+
+    .data
+    .balign 8
+    .byte 0
+size:
+    .quad 0
diff --git a/tests/asm/syscall/read-ps-ex-1.S b/tests/asm/syscall/read-ps-ex-1.S
new file mode 100644
index 0000000..330fdf4
--- /dev/null
+++ b/tests/asm/syscall/read-ps-ex-1.S
@@ -0,0 +1,46 @@
+#include "test_start.S"
+
+    {
+        setwd wsz=8, nfx=1
+        disp %ctpr1, 0f
+    }
+    {
+        addd,0 0, 0xdeadbeef, %r8
+        addd,1 0, 8, %r9
+        call %ctpr1, wbs=4
+    }
+
+#include "test_end.S"
+
+0:
+    {
+        setwd wsz=8, nfx=1
+        disp %ctpr1, 0b
+    }
+    {
+        cmpedb,0 %r1, 0, %pred0
+        addd,1 0, 0xdeadbeef, %r8
+        subd,2 %r1, 1, %r9
+    }
+        call %ctpr1, wbs=4 ? ~%pred0
+        ibranch 0f ? ~%pred0
+
+        sys_access_hw_stacks GET_PROCEDURE_STACK_SIZE, 0, 0, 0, size
+        ldd,0 [ size ], %g16
+        subd,0 %g16, 128, %g16
+        std,2 %g16, [ frame ]
+        sys_access_hw_stacks READ_PROCEDURE_STACK_EX, frame, buf, 128
+        ldd,0 0, buf, %g16
+        assert_eq_i64(%g16, 0xdeadbeef)
+0:
+        return %ctpr3
+        ct %ctpr3
+
+    .data
+    .balign 8
+buf:
+    .fill 64, 1, 0
+size:
+    .quad 0
+frame:
+    .quad 0
diff --git a/tests/asm/syscall/read-ps-ex-unaligned-1.S b/tests/asm/syscall/read-ps-ex-unaligned-1.S
new file mode 100644
index 0000000..c16303a
--- /dev/null
+++ b/tests/asm/syscall/read-ps-ex-unaligned-1.S
@@ -0,0 +1,47 @@
+#include "test_start.S"
+
+    {
+        setwd wsz=8, nfx=1
+        disp %ctpr1, 0f
+    }
+    {
+        addd,0 0, 0xdeadbeef, %r8
+        addd,1 0, 8, %r9
+        call %ctpr1, wbs=4
+    }
+
+#include "test_end.S"
+
+0:
+    {
+        setwd wsz=8, nfx=1
+        disp %ctpr1, 0b
+    }
+    {
+        cmpedb,0 %r1, 0, %pred0
+        addd,1 0, 0xdeadbeef, %r8
+        subd,2 %r1, 1, %r9
+    }
+        call %ctpr1, wbs=4 ? ~%pred0
+        ibranch 0f ? ~%pred0
+
+        sys_access_hw_stacks GET_PROCEDURE_STACK_SIZE, 0, 0, 0, size
+        ldd,0 [ size ], %g16
+        subd,0 %g16, 128, %g16
+        std,2 %g16, [ frame ]
+        sys_access_hw_stacks READ_PROCEDURE_STACK_EX, frame, buf, 128
+        ldd,0 0, buf, %g16
+        assert_eq_i64(%g16, 0xdeadbeef)
+0:
+        return %ctpr3
+        ct %ctpr3
+
+    .data
+    .balign 8
+    .byte 0
+buf:
+    .fill 64, 1, 0
+size:
+    .quad 0
+frame:
+    .quad 0
diff --git a/tests/asm/syscall/write-ps-ex-1.S b/tests/asm/syscall/write-ps-ex-1.S
new file mode 100644
index 0000000..d168935
--- /dev/null
+++ b/tests/asm/syscall/write-ps-ex-1.S
@@ -0,0 +1,33 @@
+#include "test_start.S"
+
+    {
+        setwd wsz=8, nfx=1
+        disp %ctpr1, 0f
+    }
+    {
+        addd,0 0, 0, %r0
+        call %ctpr1, wbs=4
+    }
+        assert_eq_i64(%r0, 0xdeadbeef)
+
+#include "test_end.S"
+
+0:
+        setwd wsz=8, nfx=1
+        sys_access_hw_stacks GET_PROCEDURE_STACK_SIZE, 0, 0, 0, size
+        ldd,0 [ size ], %g16
+        subd,0 %g16, 256, %g16
+        std,2 %g16, [ frame ]
+        sys_access_hw_stacks WRITE_PROCEDURE_STACK_EX, frame, buf, 8
+        assert_eq_i64(%r8, 0)
+        return %ctpr3
+        ct %ctpr3
+
+    .data
+    .balign 8
+buf:
+    .quad 0xdeadbeef
+size:
+    .quad 0
+frame:
+    .quad 0