[Xen-devel] [PATCH] xen: arm: introduce uImage probe function for Dom0

[Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx>]

Patch adds a possibility to boot dom0 kernel from uImage.
This is needed to improve bootime. Comparing to zImage,
uImage is not packed, therefore we can save time needed
to unpack.

Change-Id: If92bc895721f0b2fa0a844bb92eddc8f1fdc5498
Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx>
---
 xen/arch/arm/kernel.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
index d635a7e..45d92c9 100644
--- a/xen/arch/arm/kernel.c
+++ b/xen/arch/arm/kernel.c
@@ -16,6 +16,12 @@
 
 #include "kernel.h"
 
+#define UIMAGE32_MAGIC_OFFSET 0x8
+#define UIMAGE32_START_OFFSET 0x4
+#define UIMAGE32_END_OFFSET   0x3
+#define UIMAGE32_HEADER_LEN   0x40
+#define UIMAGE32_MAGIC        0x304d4f44
+
 #define ZIMAGE32_MAGIC_OFFSET 0x24
 #define ZIMAGE32_START_OFFSET 0x28
 #define ZIMAGE32_END_OFFSET   0x2c
@@ -188,6 +194,65 @@ static void kernel_zimage_load(struct kernel_info *info)
     }
 }
 
+/*
+ * Check if the image is a 32-bit uImage and setup kernel_info
+ */
+static int kernel_uimage32_probe(struct kernel_info *info,
+                                 paddr_t addr, paddr_t size)
+{
+    uint32_t uimage[UIMAGE32_HEADER_LEN/4];
+    uint32_t start, len;
+    struct minimal_dtb_header dtb_hdr;
+
+    if ( size < UIMAGE32_HEADER_LEN )
+        return -EINVAL;
+
+    copy_from_paddr(uimage, addr, sizeof(uimage));
+
+    if ( uimage[UIMAGE32_MAGIC_OFFSET] != UIMAGE32_MAGIC )
+        return -EINVAL;
+
+    start = be32_to_cpu(uimage[UIMAGE32_START_OFFSET]);
+    len = be32_to_cpu(uimage[UIMAGE32_END_OFFSET]);
+
+    if ( len > size )
+        return -EINVAL;
+
+    /*
+     * Check for an appended DTB.
+     */
+    if ( addr + len + sizeof(dtb_hdr) <= size )
+    {
+        copy_from_paddr(&dtb_hdr, addr + len, sizeof(dtb_hdr));
+
+        if ( be32_to_cpu(dtb_hdr.magic) == DTB_MAGIC )
+            len += be32_to_cpu(dtb_hdr.total_size);
+
+            if ( len - start > addr + size )
+                return -EINVAL;
+    }
+
+    /*
+     * If start is UIMAGE32_HEADER_LEN zImage is position independent -- load 
it
+     * at 32k from start of RAM.
+     */
+    if ( start == 0 )
+        info->zimage.start = info->mem.bank[0].start + 0x8000;
+    else
+        info->zimage.start = start;
+
+    info->zimage.kernel_addr = addr + UIMAGE32_HEADER_LEN;
+    info->zimage.len = len;
+    info->entry = info->zimage.start;
+    info->load = kernel_zimage_load;
+
+#ifdef CONFIG_ARM_64
+    info->type = DOMAIN_32BIT;
+#endif
+
+    return 0;
+}
+
 #ifdef CONFIG_ARM_64
 /*
  * Check if the image is a 64-bit Image.
@@ -398,6 +463,8 @@ int kernel_probe(struct kernel_info *info)
     rc = kernel_zimage64_probe(info, start, size);
     if (rc < 0)
 #endif
+        rc = kernel_uimage32_probe(info, start, size);
+    if(rc < 0 )
         rc = kernel_zimage32_probe(info, start, size);
     if (rc < 0)
         rc = kernel_elf_probe(info, start, size);
-- 
1.9.1


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