[PATCH 1/4] tools: kwboot: Align UART baudrate change code in BIN header to 128-bit boundary

[Pali Rohár]

ARM executable code inside the BIN header on some mvebu platforms
(e.g. A370, AXP) must always be aligned with the 128-bit boundary. This
requirement can be met by inserting dummy arguments into BIN header.

Signed-off-by: Pali Rohár <p...@kernel.org>
---
 tools/kwboot.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 6a1a030308e7..36d0cab29d1f 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -255,7 +255,7 @@ static unsigned char kwboot_baud_code[] = {
 };
 
 #define KWBOOT_BAUDRATE_BIN_HEADER_SZ (sizeof(kwboot_baud_code) + \
-                                      sizeof(struct opt_hdr_v1) + 8)
+                                      sizeof(struct opt_hdr_v1) + 8 + 16)
 
 static const char kwb_baud_magic[16] = "$baudratechange";
 
@@ -1328,11 +1328,10 @@ kwboot_add_bin_ohdr_v1(void *img, size_t *size, 
uint32_t binsz)
 {
        struct main_hdr_v1 *hdr = img;
        struct opt_hdr_v1 *ohdr;
+       uint32_t num_args;
+       uint32_t offset;
        uint32_t ohdrsz;
 
-       ohdrsz = binsz + 8 + sizeof(*ohdr);
-       kwboot_img_grow_hdr(img, size, ohdrsz);
-
        if (hdr->ext & 0x1) {
                for_each_opt_hdr_v1 (ohdr, img)
                        if (opt_hdr_v1_next(ohdr) == NULL)
@@ -1345,13 +1344,26 @@ kwboot_add_bin_ohdr_v1(void *img, size_t *size, 
uint32_t binsz)
                ohdr = (void *)(hdr + 1);
        }
 
+       /*
+        * ARM executable code inside the BIN header on some mvebu platforms
+        * (e.g. A370, AXP) must always be aligned with the 128-bit boundary.
+        * This requirement can be met by inserting dummy arguments into
+        * BIN header, if needed.
+        */
+       offset = &ohdr->data[4] - (char *)img;
+       num_args = ((16 - offset % 16) % 16) / sizeof(uint32_t);
+
+       ohdrsz = sizeof(*ohdr) + 4 + 4 * num_args + binsz + 4;
+       kwboot_img_grow_hdr(hdr, size, ohdrsz);
+
        ohdr->headertype = OPT_HDR_V1_BINARY_TYPE;
        ohdr->headersz_msb = ohdrsz >> 16;
        ohdr->headersz_lsb = cpu_to_le16(ohdrsz & 0xffff);
 
        memset(&ohdr->data[0], 0, ohdrsz - sizeof(*ohdr));
+       *(uint32_t *)&ohdr->data[0] = cpu_to_le32(num_args);
 
-       return &ohdr->data[4];
+       return &ohdr->data[4 + 4 * num_args];
 }
 
 static void
-- 
2.20.1