In order to add filesystem support, we will need to be able to seek and
write files. Add the appropriate helper functions.
Signed-off-by: Sean Anderson <sean.ander...@seco.com>
---
(no changes since v1)
arch/arm/lib/semihosting.c | 67 +++++++++++++++++++++++++++++++-------
include/semihosting.h | 20 ++++++++++++
2 files changed, 76 insertions(+), 11 deletions(-)
diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c
index 2943f7b82f..d08003cef1 100644
--- a/arch/arm/lib/semihosting.c
+++ b/arch/arm/lib/semihosting.c
@@ -1,15 +1,13 @@
// SPDX-License-Identifier: GPL-2.0+
/*
+ * Copyright (C) 2022 Sean Anderson <sean.ander...@seco.com>
* Copyright 2014 Broadcom Corporation
*/
/*
- * Minimal semihosting implementation for reading files into memory. If more
- * features like writing files or console output are required they can be
- * added later. This code has been tested on arm64/aarch64 fastmodel only.
- * An untested placeholder exists for armv7 architectures, but since they
- * are commonly available in silicon now, fastmodel usage makes less sense
- * for them.
+ * This code has been tested on arm64/aarch64 fastmodel only. An untested
+ * placeholder exists for armv7 architectures, but since they are commonly
+ * available in silicon now, fastmodel usage makes less sense for them.
*/
#include <common.h>
#include <command.h>
@@ -19,7 +17,9 @@
#define SYSOPEN 0x01
#define SYSCLOSE 0x02
+#define SYSWRITE 0x05
#define SYSREAD 0x06
+#define SYSSEEK 0x0A
#define SYSFLEN 0x0C
#define SYSERRNO 0x13
@@ -80,14 +80,22 @@ long smh_open(const char *fname, enum smh_open_mode mode)
return fd;
}
+/**
+ * struct smg_rdwr_s - Arguments for read and write
+ * @fd: A file descriptor returned from smh_open()
+ * @memp: Pointer to a buffer of memory of at least @len bytes
+ * @len: The number of bytes to read or write
+ */
+struct smh_rdwr_s {
+ long fd;
+ void *memp;
+ size_t len;
+};
+
long smh_read(long fd, void *memp, size_t len)
{
long ret;
- struct smh_read_s {
- long fd;
- void *memp;
- size_t len;
- } read;
+ struct smh_rdwr_s read;
debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
@@ -101,6 +109,24 @@ long smh_read(long fd, void *memp, size_t len)
return len - ret;
}
+long smh_write(long fd, const void *memp, size_t len, ulong *written)
+{
+ long ret;
+ struct smh_rdwr_s write;
+
+ debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
+
+ write.fd = fd;
+ write.memp = (void *)memp;
+ write.len = len;
+
+ ret = smh_trap(SYSWRITE, &write);
+ *written = len - ret;
+ if (ret)
+ return smh_errno();
+ return 0;
+}
+
long smh_close(long fd)
{
long ret;
@@ -125,6 +151,25 @@ long smh_flen(long fd)
return ret;
}
+long smh_seek(long fd, long pos)
+{
+ long ret;
+ struct smh_seek_s {
+ long fd;
+ long pos;
+ } seek;
+
+ debug("%s: fd %ld pos %ld\n", __func__, fd, pos);
+
+ seek.fd = fd;
+ seek.pos = pos;
+
+ ret = smh_trap(SYSSEEK, &seek);
+ if (ret)
+ return smh_errno();
+ return 0;
+}
+
static int smh_load_file(const char * const name, ulong load_addr,
ulong *end_addr)
{
diff --git a/include/semihosting.h b/include/semihosting.h
index d8337b6269..b53c650444 100644
--- a/include/semihosting.h
+++ b/include/semihosting.h
@@ -50,6 +50,17 @@ long smh_open(const char *fname, enum smh_open_mode mode);
*/
long smh_read(long fd, void *memp, size_t len);
+/**
+ * smh_write() - Write data to a file
+ * @fd: A file descriptor returned from smh_open()
+ * @memp: Pointer to a buffer of memory of at least @len bytes
+ * @len: The number of bytes to read
+ * @written: Pointer which will be updated with the actual bytes written
+ *
+ * Return: 0 on success or negative error on failure
+ */
+long smh_write(long fd, const void *memp, size_t len, ulong *written);
+
/**
* smh_close() - Close an open file
* @fd: A file descriptor returned from smh_open()
@@ -66,4 +77,13 @@ long smh_close(long fd);
*/
long smh_flen(long fd);
+/**
+ * smh_seek() - Seek to a position in a file
+ * @fd: A file descriptor returned from smh_open()
+ * @pos: The offset (in bytes) to seek to
+ *
+ * Return: 0 on success or negative error on failure
+ */
+long smh_seek(long fd, long pos);
+
#endif /* _SEMIHOSTING_H */
--
2.25.1
