mkimage: sunxi_egon: refactor for multi-architecture support

Refactor some functions in mkimage sunxi_egon type, in order to prepare
for adding support for more CPU architectures (e.g. RISC-V). In
addition, compatibility for operation w/o specified architecture is
kept, in this case the architecture is assumed as ARM.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

diff --git a/tools/sunxi_egon.c b/tools/sunxi_egon.c
index d1398c0..0c4540c 100644 (file)
--- a/tools/sunxi_egon.c
+++ b/tools/sunxi_egon.c
@@ -15,9 +15,28 @@
 #define PAD_SIZE                       8192
 #define PAD_SIZE_MIN                   512
 
+static int egon_get_arch(struct image_tool_params *params)
+{
+       if (params->Aflag)
+               return params->arch;
+
+       /* For compatibility, assume ARM when no architecture specified */
+       return IH_ARCH_ARM;
+}
+
 static int egon_check_params(struct image_tool_params *params)
 {
-       /* We just need a binary image file. */
+       /*
+        * Check whether the architecture is supported.
+        */
+       switch (egon_get_arch(params)) {
+       case IH_ARCH_ARM:
+               break;
+       default:
+               return EXIT_FAILURE;
+       }
+
+       /* We need a binary image file. */
        return !params->dflag;
 }
 
@@ -27,9 +46,18 @@ static int egon_verify_header(unsigned char *ptr, int image_size,
        const struct boot_file_head *header = (void *)ptr;
        uint32_t length;
 
-       /* First 4 bytes must be an ARM branch instruction. */
-       if ((le32_to_cpu(header->b_instruction) & 0xff000000) != 0xea000000)
-               return EXIT_FAILURE;
+       /*
+        * First 4 bytes must be a branch instruction of the corresponding
+        * architecture.
+        */
+       switch (egon_get_arch(params)) {
+       case IH_ARCH_ARM:
+               if ((le32_to_cpu(header->b_instruction) & 0xff000000) != 0xea000000)
+                       return EXIT_FAILURE;
+               break;
+       default:
+               return EXIT_FAILURE; /* Unknown architecture */
+       }
 
        if (memcmp(header->magic, BOOT0_MAGIC, sizeof(header->magic)))
                return EXIT_FAILURE;
@@ -78,9 +106,17 @@ static void egon_set_header(void *buf, struct stat *sbuf, int infd,
        uint32_t checksum = 0, value;
        int i;
 
-       /* Generate an ARM branch instruction to jump over the header. */
-       value = 0xea000000 | (sizeof(struct boot_file_head) / 4 - 2);
-       header->b_instruction = cpu_to_le32(value);
+       /*
+        * Different architectures need different first instruction to
+        * branch to the body.
+        */
+       switch (egon_get_arch(params)) {
+       case IH_ARCH_ARM:
+               /* Generate an ARM branch instruction to jump over the header. */
+               value = 0xea000000 | (sizeof(struct boot_file_head) / 4 - 2);
+               header->b_instruction = cpu_to_le32(value);
+               break;
+       }
 
        memcpy(header->magic, BOOT0_MAGIC, sizeof(header->magic));
        header->check_sum = cpu_to_le32(BROM_STAMP_VALUE);