xtensa_lx60: pass kernel arguments from -append

Create boot parameters in the end of SRAM region, insert kernel
arguments specified in -append there.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/hw/xtensa_bootparam.h b/hw/xtensa_bootparam.h
new file mode 100644
index 0000000..38ef32b
--- /dev/null
+++ b/hw/xtensa_bootparam.h
@@ -0,0 +1,25 @@
+#ifndef HW_XTENSA_BOOTPARAM
+#define HW_XTENSA_BOOTPARAM
+
+typedef struct BpTag {
+    uint16_t tag;
+    uint16_t size;
+} BpTag;
+
+static inline ram_addr_t put_tag(ram_addr_t addr, uint16_t tag,
+        size_t size, const void *data)
+{
+    BpTag bp_tag = {
+        .tag = tswap16(tag),
+        .size = tswap16((size + 3) & ~3),
+    };
+
+    cpu_physical_memory_write(addr, &bp_tag, sizeof(bp_tag));
+    addr += sizeof(bp_tag);
+    cpu_physical_memory_write(addr, data, size);
+    addr += (size + 3) & ~3;
+
+    return addr;
+}
+
+#endif