ARM: Add support for semihosting

Add semihosting API implementation and implement a filesystem driver
to access debugging host filesystem using it.

Tested on Freescale SabreSD board (i.MX6Q) using OpenOCD

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/arm/include/asm/semihosting.h b/arch/arm/include/asm/semihosting.h
new file mode 100644
index 0000000000..b478dadb3a
--- /dev/null
+++ b/arch/arm/include/asm/semihosting.h
@@ -0,0 +1,19 @@
+#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);
+
+#endif