[PATCH v3 05/12] xtensa: Bring in semihosting headers and config options

Jiaxun Yang jiaxun.yang at flygoat.com
Tue Jun 18 15:56:05 CEST 2024


They are all directly imported from Linux kernel.

Reviewed-by: Max Filippov <jcmvbkbc at gmail.com>
Tested-by: Max Filippov <jcmvbkbc at gmail.com>
Signed-off-by: Jiaxun Yang <jiaxun.yang at flygoat.com>
---
 arch/xtensa/Kconfig                              |  27 ++++++
 arch/xtensa/include/asm/platform/simcall-gdbio.h |  34 +++++++
 arch/xtensa/include/asm/platform/simcall-iss.h   |  73 +++++++++++++++
 arch/xtensa/include/asm/platform/simcall.h       | 110 +++++++++++++++++++++++
 4 files changed, 244 insertions(+)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 8f668cc67ed0..4afd56bca095 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -41,6 +41,33 @@ config SPL_SYS_DCACHE_OFF
 	help
 	  Do not enable data cache in SPL.
 
+config XTENSA_SEMIHOSTING
+	bool "Support semihosting"
+	help
+	  Enable Xtensa semihosting debugging support.
+
+choice
+	prompt "Semihosting interface"
+	default XTENSA_SIMCALL_ISS
+	depends on XTENSA_SEMIHOSTING
+	help
+	  Choose semihosting interface that will be used for serial port,
+	  block device and networking.
+
+config XTENSA_SIMCALL_ISS
+	bool "simcall"
+	help
+	  Use simcall instruction. simcall is only available on simulators,
+	  it does nothing on hardware.
+
+config XTENSA_SIMCALL_GDBIO
+	bool "GDBIO"
+	help
+	  Use break instruction. It is available on real hardware when GDB
+	  is attached to it via JTAG.
+
+endchoice
+
 source "board/cadence/xtfpga/Kconfig"
 
 endmenu
diff --git a/arch/xtensa/include/asm/platform/simcall-gdbio.h b/arch/xtensa/include/asm/platform/simcall-gdbio.h
new file mode 100644
index 000000000000..e642860e25a8
--- /dev/null
+++ b/arch/xtensa/include/asm/platform/simcall-gdbio.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2021 Cadence Design Systems Inc. */
+
+#ifndef _XTENSA_PLATFORM_ISS_SIMCALL_GDBIO_H
+#define _XTENSA_PLATFORM_ISS_SIMCALL_GDBIO_H
+
+/*
+ *  System call like services offered by the GDBIO host.
+ */
+
+#define SYS_open	-2
+#define SYS_close	-3
+#define SYS_read	-4
+#define SYS_write	-5
+#define SYS_lseek	-6
+
+static int errno;
+
+static inline int __simc(int a, int b, int c, int d)
+{
+	register int a1 asm("a2") = a;
+	register int b1 asm("a6") = b;
+	register int c1 asm("a3") = c;
+	register int d1 asm("a4") = d;
+	__asm__ __volatile__ (
+			"break 1, 14\n"
+			: "+r"(a1), "+r"(c1)
+			: "r"(b1), "r"(d1)
+			: "memory");
+	errno = c1;
+	return a1;
+}
+
+#endif /* _XTENSA_PLATFORM_ISS_SIMCALL_GDBIO_H */
diff --git a/arch/xtensa/include/asm/platform/simcall-iss.h b/arch/xtensa/include/asm/platform/simcall-iss.h
new file mode 100644
index 000000000000..5a1e7a1f182e
--- /dev/null
+++ b/arch/xtensa/include/asm/platform/simcall-iss.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2021 Cadence Design Systems Inc. */
+
+#ifndef _XTENSA_PLATFORM_ISS_SIMCALL_ISS_H
+#define _XTENSA_PLATFORM_ISS_SIMCALL_ISS_H
+
+/*
+ *  System call like services offered by the simulator host.
+ */
+
+#define SYS_nop		0	/* unused */
+#define SYS_exit	1	/*x*/
+#define SYS_fork	2
+#define SYS_read	3	/*x*/
+#define SYS_write	4	/*x*/
+#define SYS_open	5	/*x*/
+#define SYS_close	6	/*x*/
+#define SYS_rename	7	/*x 38 - waitpid */
+#define SYS_creat	8	/*x*/
+#define SYS_link	9	/*x (not implemented on WIN32) */
+#define SYS_unlink	10	/*x*/
+#define SYS_execv	11	/* n/a - execve */
+#define SYS_execve	12	/* 11 - chdir */
+#define SYS_pipe	13	/* 42 - time */
+#define SYS_stat	14	/* 106 - mknod */
+#define SYS_chmod	15
+#define SYS_chown	16	/* 202 - lchown */
+#define SYS_utime	17	/* 30 - break */
+#define SYS_wait	18	/* n/a - oldstat */
+#define SYS_lseek	19	/*x*/
+#define SYS_getpid	20
+#define SYS_isatty	21	/* n/a - mount */
+#define SYS_fstat	22	/* 108 - oldumount */
+#define SYS_time	23	/* 13 - setuid */
+#define SYS_gettimeofday 24	/*x 78 - getuid (not implemented on WIN32) */
+#define SYS_times	25	/*X 43 - stime (Xtensa-specific implementation) */
+#define SYS_socket      26
+#define SYS_sendto      27
+#define SYS_recvfrom    28
+#define SYS_select_one  29      /* not compatible select, one file descriptor at the time */
+#define SYS_bind        30
+#define SYS_ioctl	31
+
+#define SYS_iss_argc	1000	/* returns value of argc */
+#define SYS_iss_argv_size 1001	/* bytes needed for argv & arg strings */
+#define SYS_iss_set_argv 1002	/* saves argv & arg strings at given addr */
+
+/*
+ * SYS_select_one specifiers
+ */
+
+#define  XTISS_SELECT_ONE_READ    1
+#define  XTISS_SELECT_ONE_WRITE   2
+#define  XTISS_SELECT_ONE_EXCEPT  3
+
+static int errno;
+
+static inline int __simc(int a, int b, int c, int d)
+{
+	register int a1 asm("a2") = a;
+	register int b1 asm("a3") = b;
+	register int c1 asm("a4") = c;
+	register int d1 asm("a5") = d;
+	__asm__ __volatile__ (
+			"simcall\n"
+			: "+r"(a1), "+r"(b1)
+			: "r"(c1), "r"(d1)
+			: "memory");
+	errno = b1;
+	return a1;
+}
+
+#endif /* _XTENSA_PLATFORM_ISS_SIMCALL_ISS_H */
diff --git a/arch/xtensa/include/asm/platform/simcall.h b/arch/xtensa/include/asm/platform/simcall.h
new file mode 100644
index 000000000000..a1cb269e68f0
--- /dev/null
+++ b/arch/xtensa/include/asm/platform/simcall.h
@@ -0,0 +1,110 @@
+/*
+ * include/asm-xtensa/platform-iss/simcall.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 Tensilica Inc.
+ * Copyright (C) 2017 - 2021 Cadence Design Systems Inc.
+ */
+
+#ifndef _XTENSA_PLATFORM_ISS_SIMCALL_H
+#define _XTENSA_PLATFORM_ISS_SIMCALL_H
+
+#include <linux/bug.h>
+
+#ifdef CONFIG_XTENSA_SIMCALL_ISS
+#include <asm/platform/simcall-iss.h>
+#endif
+#ifdef CONFIG_XTENSA_SIMCALL_GDBIO
+#include <asm/platform/simcall-gdbio.h>
+#endif
+
+static inline int simc_exit(int exit_code)
+{
+#ifdef SYS_exit
+	return __simc(SYS_exit, exit_code, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return -1;
+#endif
+}
+
+static inline int simc_open(const char *file, int flags, int mode)
+{
+	return __simc(SYS_open, (int) file, flags, mode);
+}
+
+static inline int simc_close(int fd)
+{
+	return __simc(SYS_close, fd, 0, 0);
+}
+
+static inline int simc_ioctl(int fd, int request, void *arg)
+{
+#ifdef SYS_ioctl
+	return __simc(SYS_ioctl, fd, request, (int) arg);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return -1;
+#endif
+}
+
+static inline int simc_read(int fd, void *buf, size_t count)
+{
+	return __simc(SYS_read, fd, (int) buf, count);
+}
+
+static inline int simc_write(int fd, const void *buf, size_t count)
+{
+	return __simc(SYS_write, fd, (int) buf, count);
+}
+
+static inline int simc_poll(int fd)
+{
+#ifdef SYS_select_one
+	long timeval[2] = { 0, 0 };
+
+	return __simc(SYS_select_one, fd, XTISS_SELECT_ONE_READ, (int)&timeval);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return -1;
+#endif
+}
+
+static inline int simc_lseek(int fd, uint32_t off, int whence)
+{
+	return __simc(SYS_lseek, fd, off, whence);
+}
+
+static inline int simc_argc(void)
+{
+#ifdef SYS_iss_argc
+	return __simc(SYS_iss_argc, 0, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return 0;
+#endif
+}
+
+static inline int simc_argv_size(void)
+{
+#ifdef SYS_iss_argv_size
+	return __simc(SYS_iss_argv_size, 0, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return 0;
+#endif
+}
+
+static inline void simc_argv(void *buf)
+{
+#ifdef SYS_iss_set_argv
+	__simc(SYS_iss_set_argv, (int)buf, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+#endif
+}
+
+#endif /* _XTENSA_PLATFORM_ISS_SIMCALL_H */

-- 
2.43.0



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