arm: smh: Add some functions for working with the host console

This adds three wrappers around the semihosting commands for reading and
writing to the host console. We use the more standard getc/putc/puts
names instead of readc/writec/write0 for familiarity.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>

diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c
index 57ab252..7595dbc 100644 (file)
--- a/arch/arm/lib/semihosting.c
+++ b/arch/arm/lib/semihosting.c
@@ -15,8 +15,11 @@
 
 #define SYSOPEN                0x01
 #define SYSCLOSE       0x02
+#define SYSWRITEC      0x03
+#define SYSWRITE0      0x04
 #define SYSWRITE       0x05
 #define SYSREAD                0x06
+#define SYSREADC       0x07
 #define SYSSEEK                0x0A
 #define SYSFLEN                0x0C
 #define SYSERRNO       0x13
@@ -167,3 +170,18 @@ long smh_seek(long fd, long pos)
                return smh_errno();
        return 0;
 }
+
+int smh_getc(void)
+{
+       return smh_trap(SYSREADC, NULL);
+}
+
+void smh_putc(char ch)
+{
+       smh_trap(SYSWRITEC, &ch);
+}
+
+void smh_puts(const char *s)
+{
+       smh_trap(SYSWRITE0, (char *)s);
+}

diff --git a/include/semihosting.h b/include/semihosting.h
index b53c650..6f3c297 100644 (file)
--- a/include/semihosting.h
+++ b/include/semihosting.h
@@ -86,4 +86,23 @@ long smh_flen(long fd);
  */
 long smh_seek(long fd, long pos);
 
+/**
+ * smh_getc() - Read a character from stdin
+ *
+ * Return: The character read, or a negative error on failure
+ */
+int smh_getc(void);
+
+/**
+ * smh_putc() - Print a character on stdout
+ * @ch: The character to print
+ */
+void smh_putc(char ch);
+
+/**
+ * smh_write0() - Print a nul-terminated string on stdout
+ * @s: The string to print
+ */
+void smh_puts(const char *s);
+
 #endif /* _SEMIHOSTING_H */