cmd: bootvx: Pass E820 information to an x86 VxWorks kernel

E820 is critical to the kernel as it provides system memory map
information. Pass it to an x86 VxWorks kernel.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Tested-by: Jian Luo <jian.luo4@boschrexroth.de>

1 files changed, 29 insertions, 0 deletions

diff --git a/include/vxworks.h b/include/vxworks.h
index 297a70f519..f69b0084ff 100644
--- a/include/vxworks.h
+++ b/include/vxworks.h
@@ -8,6 +8,35 @@
 #ifndef _VXWORKS_H_
 #define _VXWORKS_H_
 
+/*
+ * VxWorks x86 E820 related stuff
+ *
+ * VxWorks on x86 gets E820 information from pre-defined address @
+ * 0x4a00 and 0x4000. At 0x4a00 it's an information table defined
+ * by VxWorks and the actual E820 table entries starts from 0x4000.
+ * As defined by the BIOS E820 spec, the maximum number of E820 table
+ * entries is 128 and each entry occupies 20 bytes, so it's 128 * 20
+ * = 2560 (0xa00) bytes in total. That's where VxWorks stores some
+ * information that is retrieved from the BIOS E820 call and saved
+ * later for sanity test during the kernel boot-up.
+ */
+#define VXWORKS_E820_DATA_ADDR	0x4000
+#define VXWORKS_E820_INFO_ADDR	0x4a00
+
+/* E820 info signatiure "SMAP" - System MAP */
+#define E820_SIGNATURE	0x534d4150
+
+struct e820info {
+	u32 sign;	/* "SMAP" signature */
+	u32 x0;		/* don't care, used by VxWorks */
+	u32 x1;		/* don't care, used by VxWorks */
+	u32 x2;		/* don't care, used by VxWorks */
+	u32 addr;	/* last e820 table entry addr */
+	u32 x3;		/* don't care, used by VxWorks */
+	u32 entries;	/* e820 table entry count */
+	u32 error;	/* must be zero */
+};
+
 int do_bootvx(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
 void boot_prep_vxworks(bootm_headers_t *images);
 void boot_jump_vxworks(bootm_headers_t *images);