建立工程，成功创建两个虚拟串口

source/OpenAMP/libmetal/lib/system/linux/shmem.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2015, Xilinx Inc. and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * @file	linux/shmem.c
+ * @brief	Linux libmetal shared memory handling.
+ */
+
+#include <metal/shmem.h>
+#include <metal/sys.h>
+#include <metal/utilities.h>
+
+struct metal_shmem {
+	struct metal_io_region	io;
+	metal_phys_addr_t	*phys;
+};
+
+static void metal_shmem_io_close(struct metal_io_region *io)
+{
+	metal_unmap(io->virt, io->size);
+	free((void *)io->physmap);
+}
+
+static const struct metal_io_ops metal_shmem_io_ops = {
+	NULL, NULL, NULL, NULL, NULL, metal_shmem_io_close
+};
+
+static int metal_shmem_try_map(struct metal_page_size *ps, int fd, size_t size,
+			       struct metal_io_region **result)
+{
+	size_t pages, page, phys_size;
+	struct metal_io_region *io;
+	metal_phys_addr_t *phys;
+	uint8_t *virt;
+	void *mem;
+	int error;
+
+	size = metal_align_up(size, ps->page_size);
+	pages = size / ps->page_size;
+
+	error = metal_map(fd, 0, size, 1, ps->mmap_flags, &mem);
+	if (error) {
+		metal_log(METAL_LOG_ERROR, "failed to mmap shmem - %s\n",
+			  strerror(-error));
+		return error;
+	}
+
+	error = metal_mlock(mem, size);
+	if (error) {
+		metal_log(METAL_LOG_WARNING, "failed to mlock shmem - %s\n",
+			  strerror(-error));
+	}
+
+	phys_size = sizeof(*phys) * pages;
+	phys = malloc(phys_size);
+	if (!phys) {
+		metal_unmap(mem, size);
+		return -ENOMEM;
+	}
+
+	io = malloc(sizeof(*io));
+	if (!io) {
+		free(phys);
+		metal_unmap(mem, size);
+		return -ENOMEM;
+	}
+
+	if (_metal.pagemap_fd < 0) {
+		phys[0] = 0;
+		metal_log(METAL_LOG_WARNING,
+		"shmem - failed to get va2pa mapping. use offset as pa.\n");
+		metal_io_init(io, mem, phys, size, -1, 0, &metal_shmem_io_ops);
+	} else {
+		for (virt = mem, page = 0; page < pages; page++) {
+			size_t offset = page * ps->page_size;
+			error = metal_virt2phys(virt + offset, &phys[page]);
+			if (error < 0)
+				phys[page] = METAL_BAD_OFFSET;
+		}
+		metal_io_init(io, mem, phys, size, ps->page_shift, 0,
+			&metal_shmem_io_ops);
+	}
+	*result = io;
+
+	return 0;
+}
+
+int metal_shmem_open(const char *name, size_t size,
+		     struct metal_io_region **result)
+{
+	struct metal_page_size *ps;
+	int fd, error;
+
+	error = metal_shmem_open_generic(name, size, result);
+	if (!error)
+		return error;
+
+	error = metal_open(name, 1);
+	if (error < 0) {
+		metal_log(METAL_LOG_ERROR, "Failed to open shmem file :%s\n", name);
+		return error;
+	}
+	fd = error;
+
+	/* Iterate through page sizes in decreasing order. */
+	metal_for_each_page_size_down(ps) {
+		if (ps->page_size > 2 * size)
+			continue;
+		error = metal_shmem_try_map(ps, fd, size, result);
+		if (!error)
+			break;
+	}
+
+	close(fd);
+	return error;
+}