Merge branch 'for-next/semihosting' into next

arch/arm/Kconfig

@@ -372,7 +372,7 @@ config ARM_UNWIND
 
 config ARM_SEMIHOSTING
 	bool "enable ARM semihosting support"
-	depends on !CPU_V8
+	select SEMIHOSTING
 	help
 	  This option enables ARM semihosting support in barebox. ARM
 	  semihosting is a communication discipline that allows code

arch/arm/cpu/Makefile

@@ -23,6 +23,8 @@ obj-pbl-y += setupc_$(S64_32).o cache_$(S64_32).o
 
 obj-$(CONFIG_ARM_PSCI_CLIENT) += psci-client.o
 
+obj-$(CONFIG_ARM_SEMIHOSTING) += semihosting-trap_$(S64_32).o
+
 #
 # Any variants can be called as start-armxyz.S
 #

arch/arm/lib32/semihosting-trap.S → arch/arm/cpu/semihosting-trap_32.S

@@ -2,7 +2,7 @@
 /* SPDX-FileCopyrightText: 2015 Zodiac Inflight Innovations */
 
 /*
- * semihosting-trap.S -- Assembly code needed to make a semihosting call
+ * semihosting-trap_32.S -- Assembly code needed to make a semihosting call
  *
  * Author: Andrey Smirnov <[email protected]>
  */

arch/arm/cpu/semihosting-trap_64.S

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <linux/linkage.h>
+#include <asm/unified.h>
+
+.section .text.semihosting_trap
+ENTRY(semihosting_trap)
+	hlt	#0xf000
+	ret
+ENDPROC(semihosting_trap)

arch/arm/include/asm/debug_ll.h

@@ -35,6 +35,10 @@
 #include <mach/layerscape/debug_ll.h>
 #endif
 
+#ifdef CONFIG_DEBUG_SEMIHOSTING
+#include <debug_ll/semihosting.h>
+#endif
+
 #ifdef CONFIG_DEBUG_QEMU_ARM64_VIRT
 #define DEBUG_LL_UART_ADDR		0x9000000
 #include <debug_ll/pl011.h>

arch/arm/include/asm/semihosting.h

@@ -3,19 +3,38 @@
 #ifndef __ASM_ARM_SEMIHOSTING_H
 #define __ASM_ARM_SEMIHOSTING_H
 
-int semihosting_open(const char *fname, int flags);
-int semihosting_close(int fd);
-int semihosting_writec(char c);
-int semihosting_write0(const char *str);
-ssize_t semihosting_write(int fd, const void *buf, size_t count);
-ssize_t semihosting_read(int fd, void *buf, size_t count);
-int semihosting_readc(void);
-int semihosting_isatty(int fd);
-int semihosting_seek(int fd, loff_t pos);
-int semihosting_flen(int fd);
-int semihosting_remove(const char *fname);
-int semihosting_rename(const char *fname1, const char *fname2);
-int semihosting_errno(void);
-int semihosting_system(const char *command);
+#include <asm-generic/semihosting.h>
+#include <asm/unified.h>
+
+static inline void semihosting_putc(void *unused, int c)
+{
+	/* We may not be relocated yet here, so we push
+	 * to stack and take address of that
+	 */
+#ifdef CONFIG_CPU_64
+	asm volatile (
+		"stp %0, xzr, [sp, #-16]!\n"
+		"mov x1, sp\n"
+		"mov x0, #0x03\n"
+	 	"hlt #0xf000\n"
+		"add sp, sp, #16\n"
+		: /* No outputs */
+		: "r" ((long)c)
+		: "x0", "x1", "x2", "x3", "x12", "memory"
+	);
+#else
+	asm volatile (
+		"push {%0}\n"
+		"mov r1, sp\n"
+		"mov r0, #0x03\n"
+	 ARM(	"bkpt #0x123456\n")
+	 THUMB(	"bkpt #0xAB\n")
+		"pop {%0}\n"
+		: /* No outputs */
+		: "r" (c)
+		: "r0", "r1", "r2", "r3", "r12", "memory"
+	);
+#endif
+}
 
 #endif

arch/arm/lib32/Makefile

@@ -23,7 +23,6 @@ pbl-y	+= runtime-offset.o
 obj-$(CONFIG_ARM_OPTIMZED_STRING_FUNCTIONS)	+= memcpy.o
 obj-$(CONFIG_ARM_OPTIMZED_STRING_FUNCTIONS)	+= memset.o
 obj-$(CONFIG_ARM_UNWIND) += unwind.o
-obj-$(CONFIG_ARM_SEMIHOSTING) += semihosting-trap.o semihosting.o
 obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_ARM_MODULE_PLTS) += module-plts.o
 extra-y += barebox.lds

common/Kconfig.debug_ll

@@ -337,6 +337,19 @@ config DEBUG_QEMU_ARM64_VIRT
 	bool "QEMU ARM64 Virt PL011 console"
 	depends on ARCH_ARM64_VIRT
 
+config DEBUG_SEMIHOSTING
+	bool "Semihosting console"
+	depends on SEMIHOSTING
+	help
+	  Semihosting enables code to use the I/O facilities on a
+	  host debugger/emulator through a simple supervisor call.
+	  The host debugger or emulator must have semihosting enabled
+	  for the supervisor call to be trapped, otherwise barebox
+	  will crash.
+
+	  Say Y here if you want low-level debugging support
+	  using semihosting writec.
+
 endchoice
 
 config DEBUG_LL_NS16550

drivers/firmware/Kconfig

@@ -1,6 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0-only
 menu "Firmware Drivers"
 
+config SEMIHOSTING
+	bool
+	select HAS_DEBUG_LL
+
 config FIRMWARE_ALTERA_SERIAL
 	bool "Altera SPI programming"
 	depends on OFDEVICE

drivers/firmware/Makefile

@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_SEMIHOSTING) += semihosting.o
 obj-$(CONFIG_FIRMWARE_ALTERA_SERIAL) += altera_serial.o
 obj-$(CONFIG_FIRMWARE_ALTERA_SOCFPGA) += socfpga.o socfpga_sdr.o
 obj-$(CONFIG_FIRMWARE_ZYNQMP_FPGA) += zynqmp-fpga.o

arch/arm/lib32/semihosting.c → drivers/firmware/semihosting.c

@@ -41,9 +41,15 @@ enum {
 	SEMIHOSTING_SYS_SYSTEM	= 0x12,
 };
 
-uint32_t semihosting_trap(uint32_t sysnum, void *addr);
+long semihosting_trap(ulong sysnum, void *addr);
 
-static uint32_t semihosting_flags_to_mode(int flags)
+static long semihosting_call(ulong sysnum, void *addr)
+{
+	long ret = semihosting_trap(sysnum, addr);
+	return ret >= 0 ? ret : -semihosting_errno();
+}
+
+static ulong semihosting_flags_to_mode(int flags)
 {
 	static const int semihosting_open_modeflags[12] = {
 		O_RDONLY,
@@ -72,148 +78,153 @@ static uint32_t semihosting_flags_to_mode(int flags)
 int semihosting_open(const char *fname, int flags)
 {
 	struct __packed {
-		uint32_t fname;
-		uint32_t mode;
-		uint32_t len;
+		ulong fname;
+		ulong mode;
+		ulong len;
 	} open = {
-		.fname = (uint32_t)fname,
+		.fname = virt_to_phys(fname),
 		.len = strlen(fname),
 		.mode = semihosting_flags_to_mode(flags),
 	};
 
-	return semihosting_trap(SEMIHOSTING_SYS_OPEN, &open);
+	return semihosting_call(SEMIHOSTING_SYS_OPEN, &open);
 }
 EXPORT_SYMBOL(semihosting_open);
 
 int semihosting_close(int fd)
 {
-	return semihosting_trap(SEMIHOSTING_SYS_CLOSE, &fd);
+	return semihosting_call(SEMIHOSTING_SYS_CLOSE, &fd);
 }
 EXPORT_SYMBOL(semihosting_close);
 
-int semihosting_writec(char c)
+void semihosting_writec(char c)
 {
-	return semihosting_trap(SEMIHOSTING_SYS_WRITEC, &c);
+	(void)semihosting_trap(SEMIHOSTING_SYS_WRITEC, &c);
 }
 EXPORT_SYMBOL(semihosting_writec);
 
-int semihosting_write0(const char *str)
+void semihosting_write0(const char *str)
 {
-	return semihosting_trap(SEMIHOSTING_SYS_WRITE0, (void *)str);
+	(void)semihosting_trap(SEMIHOSTING_SYS_WRITE0, (void *)str);
 }
 EXPORT_SYMBOL(semihosting_write0);
 
 struct __packed semihosting_file_io {
-	uint32_t fd;
-	uint32_t memp;
-	uint32_t len;
+	ulong fd;
+	ulong memp;
+	ulong len;
 };
 
 ssize_t semihosting_write(int fd, const void *buf, size_t count)
 {
+	ssize_t ret;
 	struct semihosting_file_io write = {
 		.fd = fd,
-		.memp = (uint32_t)buf,
+		.memp = virt_to_phys(buf),
 		.len = count,
 	};
 
-	return semihosting_trap(SEMIHOSTING_SYS_WRITE, &write);
+	ret = semihosting_call(SEMIHOSTING_SYS_WRITE, &write);
+
+	return ret >= 0 ? count - ret : ret;
 }
 EXPORT_SYMBOL(semihosting_write);
 
 ssize_t semihosting_read(int fd, void *buf, size_t count)
 {
+	ssize_t ret;
 	struct semihosting_file_io read = {
 		.fd = fd,
-		.memp = (uint32_t)buf,
+		.memp = virt_to_phys(buf),
 		.len = count,
 	};
 
-	return semihosting_trap(SEMIHOSTING_SYS_READ, &read);
+	ret = semihosting_call(SEMIHOSTING_SYS_READ, &read);
+
+	return ret >= 0 ? count - ret : ret;
 }
 EXPORT_SYMBOL(semihosting_read);
 
 int semihosting_readc(void)
 {
-	return semihosting_trap(SEMIHOSTING_SYS_READC, NULL);
+	return semihosting_call(SEMIHOSTING_SYS_READC, NULL);
 }
 EXPORT_SYMBOL(semihosting_readc);
 
 int semihosting_isatty(int fd)
 {
-	return semihosting_trap(SEMIHOSTING_SYS_ISATTY, &fd);
+	return semihosting_call(SEMIHOSTING_SYS_ISATTY, &fd);
 }
 EXPORT_SYMBOL(semihosting_isatty);
 
-int semihosting_seek(int fd, loff_t pos)
+off_t semihosting_seek(int fd, off_t pos)
 {
 	struct __packed {
-		uint32_t fd;
-		uint32_t pos;
+		ulong fd;
+		ulong pos;
 	} seek = {
 		.fd = fd,
 		.pos = pos,
 	};
 
-	return semihosting_trap(SEMIHOSTING_SYS_SEEK, &seek);
+	return semihosting_call(SEMIHOSTING_SYS_SEEK, &seek);
 }
 EXPORT_SYMBOL(semihosting_seek);
-
-int semihosting_flen(int fd)
+off_t semihosting_flen(int fd)
 {
-	return semihosting_trap(SEMIHOSTING_SYS_FLEN, &fd);
+	return semihosting_call(SEMIHOSTING_SYS_FLEN, &fd);
 }
 EXPORT_SYMBOL(semihosting_flen);
 
 int semihosting_remove(const char *fname)
 {
 	struct __packed {
-		uint32_t fname;
-		uint32_t fname_length;
+		ulong fname;
+		ulong fname_length;
 	} remove = {
-		.fname = (uint32_t)fname,
+		.fname = virt_to_phys(fname),
 		.fname_length = strlen(fname),
 	};
 
-	return semihosting_trap(SEMIHOSTING_SYS_REMOVE, &remove);
+	return semihosting_call(SEMIHOSTING_SYS_REMOVE, &remove);
 }
 EXPORT_SYMBOL(semihosting_remove);
 
 int semihosting_rename(const char *fname1, const char *fname2)
 {
 	struct __packed {
-		uint32_t fname1;
-		uint32_t fname1_length;
-		uint32_t fname2;
-		uint32_t fname2_length;
+		ulong fname1;
+		ulong fname1_length;
+		ulong fname2;
+		ulong fname2_length;
 	} rename = {
-		.fname1 = (uint32_t)fname1,
+		.fname1 = virt_to_phys(fname1),
 		.fname1_length = strlen(fname1),
-		.fname2 = (uint32_t)fname2,
+		.fname2 = virt_to_phys(fname2),
 		.fname2_length = strlen(fname2),
 	};
 
-	return semihosting_trap(SEMIHOSTING_SYS_RENAME, &rename);
+	return semihosting_call(SEMIHOSTING_SYS_RENAME, &rename);
 }
 EXPORT_SYMBOL(semihosting_rename);
 
 int semihosting_errno(void)
 {
-	return semihosting_trap(SEMIHOSTING_SYS_ERRNO, NULL);
+	return semihosting_call(SEMIHOSTING_SYS_ERRNO, NULL);
 }
 EXPORT_SYMBOL(semihosting_errno);
 
 
 int semihosting_system(const char *command)
 {
 	struct __packed {
-		uint32_t cmd;
-		uint32_t cmd_len;
+		ulong cmd;
+		ulong cmd_len;
 	} system = {
-		.cmd = (uint32_t)command,
+		.cmd = virt_to_phys(command),
 		.cmd_len = strlen(command),
 	};
 
-	return semihosting_trap(SEMIHOSTING_SYS_SYSTEM, &system);
+	return semihosting_call(SEMIHOSTING_SYS_SYSTEM, &system);
 }
 EXPORT_SYMBOL(semihosting_system);

drivers/serial/Kconfig

@@ -151,4 +151,12 @@ config SERIAL_SBI
 	  Select this option if you are building barebox for a RISCV platform
 	  that implements a serial over SBI.
 
+config SERIAL_SEMIHOSTING
+	bool "Semihosting console"
+	depends on SEMIHOSTING
+	help
+	  Select this option if you want barebox to be able to output to
+	  the semihosting console implemented by a debugger or emulator.
+	  This console can not be read from.
+
 endmenu

drivers/serial/Makefile

@@ -25,3 +25,4 @@ obj-$(CONFIG_VIRTIO_CONSOLE)			+= virtio_console.o
 obj-$(CONFIG_SERIAL_SIFIVE)			+= serial_sifive.o
 obj-$(CONFIG_SERIAL_SBI)			+= serial_sbi.o
 obj-$(CONFIG_SOC_LITEX)				+= serial_litex.o
+obj-$(CONFIG_SERIAL_SEMIHOSTING)		+= serial_semihosting.o