mboxd: Add support for file-backed flash devices.

This commit adds a new file based backing source.  The file based
backing source takes a raw pnor image that is usually flashed to a mtd
device.

This backing source enabled rapid testing of pnor images.

Tested on Witherspoon with the VPNOR and file backends, and Romulus for
the MTD and file backends.

Change-Id: I253ecfa6b58d071c7982f153ad50da8e4ad39fa2
Signed-off-by: Evan Lojewski <github@meklort.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>

1 files changed, 282 insertions, 0 deletions

diff --git a/file/backend.c b/file/backend.c
new file mode 100644
index 0000000..224719d
--- /dev/null
+++ b/file/backend.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (C) 2018 IBM Corp.
+// Copyright (C) 2018 Evan Lojewski.
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <mtd/mtd-abi.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/timerfd.h>
+#include <sys/types.h>
+#include <syslog.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "backend.h"
+#include "lpc.h"
+#include "mboxd.h"
+
+#define MIN(__x__, __y__)  (((__x__) < (__y__)) ? (__x__) : (__y__))
+
+#define FILE_ERASE_SIZE (4 * 1024)
+
+struct file_data {
+	int fd;
+};
+
+static int file_dev_init(struct backend *backend, void *data)
+{
+	struct mtd_info_user info;
+	const char *path = data;
+	struct file_data *priv;
+	struct stat statbuf;
+	int rc = 0;
+
+	if (!path) {
+		MSG_ERR("No PNOR file specified\n");
+		return -EINVAL;
+	}
+
+	priv = malloc(sizeof(*priv));
+	if (!priv)
+		return -errno;
+
+	MSG_DBG("Opening %s\n", path);
+
+	priv->fd = open(path, O_RDWR);
+	if (priv->fd < 0) {
+		MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n", path,
+			strerror(errno));
+		rc = -errno;
+		goto cleanup_data;
+	}
+
+	/* Don't attach to mtd devices. */
+	rc = ioctl(priv->fd, MEMGETINFO, &info);
+	if (rc != -1) {
+		rc = -errno;
+		goto cleanup_fd;
+	}
+
+	rc = fstat(priv->fd, &statbuf);
+	if (rc < 0) {
+		rc = -errno;
+		goto cleanup_fd;
+	}
+
+	if (backend->flash_size == 0) {
+		MSG_INFO("Flash size should be supplied on the commandline.\n");
+		backend->flash_size = statbuf.st_size;
+	}
+
+	/* Pick an erase size congruent with partition alignment */
+	backend->erase_size_shift = log_2(FILE_ERASE_SIZE);
+	backend->block_size_shift = backend->erase_size_shift;
+	MSG_DBG("Flash erase size: 0x%.8x\n", FILE_ERASE_SIZE);
+
+	backend->priv = priv;
+	return rc;
+
+cleanup_fd:
+	close(priv->fd);
+cleanup_data:
+	free(priv);
+	return rc;
+}
+
+static void file_dev_free(struct backend *backend)
+{
+	struct file_data *priv = backend->priv;
+
+	close(priv->fd);
+	free(priv);
+}
+
+/* Flash Functions */
+
+/*
+ * file_erase() - Erase the flash
+ * @context:	The mbox context pointer
+ * @offset:	The flash offset to erase (bytes)
+ * @size:	The number of bytes to erase
+ *
+ * Return:	0 on success otherwise negative error code
+ */
+static int file_erase(struct backend *backend, uint32_t offset, uint32_t count)
+{
+	const uint32_t erase_size = 1 << backend->erase_size_shift;
+	struct file_data *priv = backend->priv;
+	struct erase_info_user erase_info = {0};
+	int rc;
+
+	MSG_DBG("Erase flash @ 0x%.8x for 0x%.8x\n", offset, count);
+
+	uint8_t* erase_buf = (uint8_t*)malloc(count);
+	if (!erase_buf) {
+		MSG_ERR("Couldn't malloc erase buffer. %s\n", strerror(errno));
+		return -1;
+	}
+	memset(erase_buf, 0xFF, erase_size);
+	rc = pwrite(priv->fd, erase_buf, count, offset);
+	free(erase_buf);
+
+	if (rc < 0) {
+		MSG_ERR("Couldn't erase flash at 0x%.8x\n", erase_info.start);
+		return -errno;
+	}
+
+
+	return 0;
+}
+
+#define CHUNKSIZE (64 * 1024)
+
+/*
+ * file_copy() - Copy data from the flash device into a provided buffer
+ * @context:	The backend context pointer
+ * @offset:	The flash offset to copy from (bytes)
+ * @mem:	The buffer to copy into (must be of atleast 'size' bytes)
+ * @size:	The number of bytes to copy
+ * Return:	Number of bytes copied on success, otherwise negative error
+ *		code. file_copy will copy at most 'size' bytes, but it may
+ *		copy less.
+ */
+static int64_t file_copy(struct backend *backend, uint32_t offset,
+			  void *mem, uint32_t size)
+{
+	struct file_data *priv = backend->priv;
+	int32_t size_read;
+	void *start = mem;
+
+	MSG_DBG("Copy flash to %p for size 0x%.8x from offset 0x%.8x\n", mem,
+		size, offset);
+	if (lseek(priv->fd, offset, SEEK_SET) != offset) {
+		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
+			strerror(errno));
+		return -errno;
+	}
+
+	do {
+		size_read = read(priv->fd, mem, min_u32(CHUNKSIZE, size));
+		if (size_read < 0) {
+			MSG_ERR("Couldn't copy file into ram: %s\n",
+				strerror(errno));
+			return -errno;
+		}
+
+		size -= size_read;
+		mem += size_read;
+	} while (size && size_read);
+
+	return size_read ? mem - start : -EIO;
+}
+
+/*
+ * file_write() - Write the flash from a provided buffer
+ * @context:	The mbox context pointer
+ * @offset:	The flash offset to write to (bytes)
+ * @buf:	The buffer to write from (must be of atleast size)
+ * @size:	The number of bytes to write
+ *
+ * Return:	0 on success otherwise negative error code
+ */
+static int file_write(struct backend *backend, uint32_t offset, void *buf,
+		       uint32_t count)
+{
+	struct file_data *priv = backend->priv;
+	uint32_t buf_offset = 0;
+	int rc;
+
+	MSG_DBG("Write flash @ 0x%.8x for 0x%.8x from %p\n", offset, count,
+		buf);
+
+	if (lseek(priv->fd, offset, SEEK_SET) != offset) {
+		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
+			strerror(errno));
+		return -errno;
+	}
+
+	while (count) {
+		rc = write(priv->fd, buf + buf_offset, count);
+		if (rc < 0) {
+			MSG_ERR("Couldn't write to file, write lost: %s\n",
+				strerror(errno));
+			return -errno;
+		}
+		count -= rc;
+		buf_offset += rc;
+	}
+
+	return 0;
+}
+
+/*
+ * file_reset() - Reset the lpc bus mapping
+ * @context:    The backend context pointer
+ * @buf:	Pointer to the LPC reserved memory
+ * @count:	The size of the LPC reserved memory
+ *
+ * Return:      0 on success otherwise negative error code
+ */
+static int file_reset(struct backend *backend, void *buf, uint32_t count)
+{
+	struct file_data *priv = backend->priv;
+	size_t len;
+	int rc;
+
+	len = MIN(backend->flash_size, count);
+
+	/* Ugh, otherwise we need to parse the FFS image */
+	assert(len == backend->flash_size);
+
+	/* Preload Flash contents into memory window */
+	rc = pread(priv->fd, buf, len, 0);
+	if (rc < 0)
+		return -errno;
+
+	return reset_lpc_memory;
+}
+
+static const struct backend_ops file_ops = {
+	.init = file_dev_init,
+	.free = file_dev_free,
+	.copy = file_copy,
+	.erase = file_erase,
+	.write = file_write,
+	.reset = file_reset,
+	.validate = NULL,
+};
+
+struct backend backend_get_file(void)
+{
+	struct backend be = {0};
+
+	be.ops = &file_ops;
+
+	return be;
+}
+
+int backend_probe_file(struct backend *master, const char *path)
+{
+	struct backend with;
+
+	assert(master);
+	with = backend_get_file();
+
+	return backend_init(master, &with, (void *)path);
+}