Extract the OP-TEE overlay fragements information into a dedicated
overlay buffer and add the handoff data on success. The handoff data is
used by next commit.

Signed-off-by: Marco Felsch <[email protected]>
---
 arch/arm/mach-imx/esdctl.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/arch/arm/mach-imx/esdctl.c b/arch/arm/mach-imx/esdctl.c
index 
964d438e3f3433332e351d9a70f91857ee33e0b4..b9393fba4ab0f14992d2fec32b0e1b7f1d4bbdfd
 100644
--- a/arch/arm/mach-imx/esdctl.c
+++ b/arch/arm/mach-imx/esdctl.c
@@ -1015,10 +1015,50 @@ resource_size_t imx8m_barebox_earlymem_size(unsigned 
buswidth)
        return min_t(resource_size_t, SZ_4G - MX8M_DDR_CSD1_BASE_ADDR, size);
 }
 
+static void imx8m_extract_optee_fdto(void)
+{
+       unsigned int early_fdt_sz, fdto_size;
+       void *early_fdt, *fdto_dst;
+
+       imx_scratch_get_fdt(&early_fdt, &early_fdt_sz);
+       /* SCRATCH_FDT_SIZE == 0, e.g. if OP-TEE w/o CFG_DT support is used */
+       if (early_fdt_sz == 0)
+               return;
+
+       imx_scratch_get_optee_fdto(&fdto_dst, &fdto_size);
+       /* SCRATCH_FDTO_SIZE == 0 if feature (back-channel) is not required */
+       if (fdto_size == 0) {
+               pr_debug("OP-TEE dest DTBO size == 0, skip extracting\n");
+               return;
+       }
+
+       /*
+        * OP-TEE DT handling is really cumbersome. In case an external DT was
+        * supplied, OP-TEE re-use this DT and appends overlays.
+        *
+        * Extract the overlays into a single overlay file to make it easier
+        * to apply these onto the barebox and kernel DT.
+        *
+        * It will become easier once barebox supports the transfer-list
+        * protocol and the protocol itself has overlay-entry support.
+        */
+       if (optee_extract_fdto(early_fdt, fdto_dst, fdto_size)) {
+               pr_warn("Failed to extract OP-TEE FDTO, continue without 
FDTO\n");
+               /*
+                * Don't BUG() because the system may have compile-time config
+                * support
+                */
+               return;
+       }
+
+       handoff_data_add(HANDOFF_DATA_BL32_DT_OVL, fdto_dst, fdto_size);
+}
+
 static void __noreturn imx8m_barebox_entry(void *boarddata, unsigned buswidth)
 {
        imx8m_init_scratch_space(buswidth, false);
        optee_set_membase(imx_scratch_get_optee_hdr());
+       imx8m_extract_optee_fdto();
        barebox_arm_entry(MX8M_DDR_CSD1_BASE_ADDR,
                          imx8m_barebox_earlymem_size(buswidth), boarddata);
 }

-- 
2.47.3


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