shofel

Shofel/payloads/intermezzo.c

@@ -0,0 +1,55 @@
+#include "types.h"
+#include "t124.h"
+
+extern u32 __payload_bin_start;
+extern u32 __payload_bin_end;
+
+typedef void (*post_relocation_t)( void );
+typedef void (*payload_ep_t)( void );
+typedef void (*_memcpy_t)( void *dst, const void *src, size_t len );
+
+void _memcpy( void *dst, const void *src, size_t len ) {
+
+    for ( size_t i = 0; i < len; i++ ) {
+        ( (u8 *)dst )[i] = ( (u8 *)src )[i];
+    }
+
+}
+// Probably I could trust in have relative PC branches, so no address would
+// require to be updated. This would work since there is a whole new copy
+// of the binary on the relocated area and PC would be working on that area
+// but having memcpy address on a register and update it to the relocated
+// area when required should improve the chances of the compiler not messing
+// up with the memcpy calls.
+register _memcpy_t memcpy asm("r7");
+        
+void _post_relocation() {
+
+    // Same with these arguments....
+    register u32 payload_bef_len = *( (u32 *) IRAM_ADD_PAYLOAD_BEF_LENVAR );
+    register u32 payload_aft_len = *( (u32 *) IRAM_ADD_PAYLOAD_AFT_LENVAR );
+    register u32 payload_thumb_mode = *( (u32 *) IRAM_ADD_PAYLOAD_THUMB_MODE );
+
+    memcpy -= INTERMEZZO_LEN;
+    memcpy( (u8 *) BOOTROM_PAYLOAD_ENTRY, (u8 *) IRAM_ADD_PAYLOAD_START, payload_bef_len );
+    memcpy( (u8 *) (BOOTROM_PAYLOAD_ENTRY + payload_bef_len), (u8 *) IRAM_ADD_PAYLOAD_CONT, payload_aft_len );
+
+    payload_ep_t payload_ep = (payload_ep_t) ( BOOTROM_PAYLOAD_ENTRY | payload_thumb_mode );
+    payload_ep();
+
+}
+
+__attribute__((section(".init")))
+void pre_relocation() {
+
+    u32 payload_bin_size = (u32)&__payload_bin_end - (u32)&__payload_bin_start;
+    u8 *dest = (u8 *) ( BOOTROM_PAYLOAD_ENTRY - INTERMEZZO_LEN );
+
+    memcpy = _memcpy;
+    memcpy( dest, &__payload_bin_start, payload_bin_size );
+ 
+    post_relocation_t post_relocation = _post_relocation - INTERMEZZO_LEN;
+    post_relocation();
+
+}
+