api: storage: Add the missing write operation support

API_dev_write(va_list ap) is currently lacking the write support
to storage devices because, historically, those devices did not
implement block_write()

The solution has been tested by loading and booting a (patched)
GRUB instance in a QEMU vexpress-a9 environment. The disk write
operations were triggered with GRUB's save_env command.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>

diff --git a/api/api.c b/api/api.c
index bc9454eb4b631e81f78f9fd033c24b019e77fb7f..71fa03804e6f6459b7e2b7392ddcc14bf7f7db10 100644 (file)
--- a/api/api.c
+++ b/api/api.c
@@ -295,27 +295,31 @@ static int API_dev_close(va_list ap)
 
 
 /*
- * Notice: this is for sending network packets only, as U-Boot does not
- * support writing to storage at the moment (12.2007)
- *
  * pseudo signature:
  *
  * int API_dev_write(
  *     struct device_info *di,
  *     void *buf,
- *     int *len
+ *     int *len,
+ *     unsigned long *start
  * )
  *
  * buf:        ptr to buffer from where to get the data to send
  *
- * len: length of packet to be sent (in bytes)
+ * len: ptr to length to be read
+ *      - network: len of packet to be sent (in bytes)
+ *      - storage: # of blocks to write (can vary in size depending on define)
  *
+ * start: ptr to start block (only used for storage devices, ignored for
+ *        network)
  */
 static int API_dev_write(va_list ap)
 {
        struct device_info *di;
        void *buf;
-       int *len;
+       lbasize_t *len_stor, act_len_stor;
+       lbastart_t *start;
+       int *len_net;
        int err = 0;
 
        /* 1. arg is ptr to the device_info struct */
@@ -333,23 +337,36 @@ static int API_dev_write(va_list ap)
        if (buf == NULL)
                return API_EINVAL;
 
-       /* 3. arg is length of buffer */
-       len = (int *)va_arg(ap, uintptr_t);
-       if (len == NULL)
-               return API_EINVAL;
-       if (*len <= 0)
-               return API_EINVAL;
+       if (di->type & DEV_TYP_STOR) {
+               /* 3. arg - ptr to var with # of blocks to write */
+               len_stor = (lbasize_t *)va_arg(ap, uintptr_t);
+               if (!len_stor)
+                       return API_EINVAL;
+               if (*len_stor <= 0)
+                       return API_EINVAL;
 
-       if (di->type & DEV_TYP_STOR)
-               /*
-                * write to storage is currently not supported by U-Boot:
-                * no storage device implements block_write() method
-                */
-               return API_ENODEV;
+               /* 4. arg - ptr to var with start block */
+               start = (lbastart_t *)va_arg(ap, uintptr_t);
 
-       else if (di->type & DEV_TYP_NET)
-               err = dev_write_net(di->cookie, buf, *len);
-       else
+               act_len_stor = dev_write_stor(di->cookie, buf, *len_stor, *start);
+               if (act_len_stor != *len_stor) {
+                       debugf("write @ %llu: done %llu out of %llu blocks",
+                                  (uint64_t)blk, (uint64_t)act_len_stor,
+                                  (uint64_t)len_stor);
+                       return API_EIO;
+               }
+
+       } else if (di->type & DEV_TYP_NET) {
+               /* 3. arg points to the var with length of packet to write */
+               len_net = (int *)va_arg(ap, uintptr_t);
+               if (!len_net)
+                       return API_EINVAL;
+               if (*len_net <= 0)
+                       return API_EINVAL;
+
+               err = dev_write_net(di->cookie, buf, *len_net);
+
+       } else
                err = API_ENODEV;
 
        return err;

diff --git a/api/api_private.h b/api/api_private.h
index 8d97ca95a2a4eaf86314e5e5b115800b61c15145..07fd50ad3a363f42c1070158ff1fa2d3378452f2 100644 (file)
--- a/api/api_private.h
+++ b/api/api_private.h
@@ -22,6 +22,7 @@ int   dev_close_stor(void *);
 int    dev_close_net(void *);
 
 lbasize_t      dev_read_stor(void *, void *, lbasize_t, lbastart_t);
+lbasize_t      dev_write_stor(void *, void *, lbasize_t, lbastart_t);
 int            dev_read_net(void *, void *, int);
 int            dev_write_net(void *, void *, int);
 

diff --git a/api/api_storage.c b/api/api_storage.c
index 2b90c18aaec93a1dcb8914e80e37d41842d88980..7ae03ac2306eb97b806592eee429260a0fe0c21d 100644 (file)
--- a/api/api_storage.c
+++ b/api/api_storage.c
@@ -349,3 +349,27 @@ lbasize_t dev_read_stor(void *cookie, void *buf, lbasize_t len, lbastart_t start
        return dd->block_read(dd, start, len, buf);
 #endif /* defined(CONFIG_BLK) */
 }
+
+
+lbasize_t dev_write_stor(void *cookie, void *buf, lbasize_t len, lbastart_t start)
+{
+       struct blk_desc *dd = (struct blk_desc *)cookie;
+       int type = dev_stor_type(dd);
+
+       if (type == ENUM_MAX)
+               return 0;
+
+       if (!dev_stor_is_valid(type, dd))
+               return 0;
+
+#ifdef CONFIG_BLK
+       return blk_dwrite(dd, start, len, buf);
+#else
+       if (dd->block_write == NULL) {
+               debugf("no block_write() for device 0x%08x\n", cookie);
+               return 0;
+       }
+
+       return dd->block_write(dd, start, len, buf);
+#endif /* defined(CONFIG_BLK) */
+}