[U-Boot] [PATCH v3 5/5] README.vxworks: add a document describing the new VxWorks boot interface

[myan]

From: Miao Yan <miao.yan at windriver.com>

Signed-off-by: Miao Yan <miao.yan at windriver.com>
---
changes:

 v2->v3: rebase to master: d19ad726bcd5d9106f7ba9c750462fcc369f1020
 v1->v2: none

 doc/README.vxworks |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 doc/README.vxworks

diff --git a/doc/README.vxworks b/doc/README.vxworks
new file mode 100644
index 0000000..4cb302e
--- /dev/null
+++ b/doc/README.vxworks
@@ -0,0 +1,19 @@
+From VxWorks 6.9+ (not include 6.9), VxWorks starts adopting device tree as its hardware
+decription mechansim (for PowerPC and ARM), thus requiring boot interface changes.
+This section will describe the new interface.
+
+For PowerPC, the calling convention of the new VxWorks entry point conforms to the ePAPR standard,
+which is shown below (see ePAPR for more details):
+
+    void (*kernel_entry)(fdt_addr,
+              0, 0, EPAPR_MAGIC, boot_IMA, 0, 0)
+
+For ARM, the calling convention is show below:
+
+    void (*kernel_entry)(void *fdt_addr)
+
+When booting new VxWorks kernel (uImage format), the parameters passed to bootm is like below:
+
+    bootm <kernel image address> - <device tree address>
+
+The do_bootvx command still works as it was for older VxWorks kernels.
-- 
1.7.9.5