pbio/platform/ev3: Use linker script and ELF loader to copy vector table

U-boot will automatically copy the table to the ARM local RAM, so
we no longer need to manually perform the copy in SystemInit.

Author: ArcaneNibble

lib/pbio/platform/ev3/exceptionhandler.S

@@ -1,9 +1,5 @@
 @ SPDX-License-Identifier: MPL-1.0
 @ Copyright (c) 2016 Tobias Schießl
-        .global ExceptionHandler
-        .global IRQHandler
-        .global SWIHandler
-        
         .set  MODE_USR, 0x10            
         .set  MODE_FIQ, 0x11
         .set  MODE_IRQ, 0x12
@@ -16,22 +12,21 @@
         .equ I_F_BIT, 0xC0 
         .equ MASK_SWI_NUM, 0xFF000000
 
-        .text
+        @ This will be placed at 0xffff0000 by the linker script
+        .section .vector,"ax",%progbits
 
         .code 32
 
-@ Default entry for all vectors except Reset is "B ExceptionHandler" so each interrupt would cause a reset
-@ Since I can only say that the IRQ Handler works, we leave the remaining ones as they are
-ExceptionHandler:
+ResetToEntry:
         B Entry
-        B ExceptionHandler
+        B ResetToEntry
         B SWIHandler
-        B ExceptionHandler
-        B ExceptionHandler
-        B ExceptionHandler
+        B ResetToEntry
+        B ResetToEntry
+        B ResetToEntry
         B IRQHandler
         NOP @ Fall to FIQHandler
-        
+
 FIQHandler:
         STMFD    r13!, {r0-r7, lr}
         LDR      r0, =0xFFFEF600

lib/pbio/platform/ev3/platform.c

@@ -393,19 +393,6 @@ const pbdrv_ioport_platform_data_t pbdrv_ioport_platform_data[PBDRV_CONFIG_IOPOR
     },
 };
 
-// See exceptionhandler.S
-extern void ExceptionHandler(void);
-
-void copy_vector_table(void) {
-    unsigned int *dest = (unsigned int *)0xFFFF0000;
-    unsigned int *addrExceptionHandler = (unsigned int *)ExceptionHandler;
-    int i = 1;
-
-    for (; i < 8 + 2048; ++i) {
-        dest[i] = addrExceptionHandler[i];
-    }
-}
-
 unsigned int EDMAVersionGet(void) {
     return 1;
 }
@@ -558,8 +545,6 @@ void SystemInit(void) {
 
     SysCfgRegistersUnlock();
 
-    copy_vector_table();
-
     // Initialize advanced interrupt controller (AINTC)
     IntAINTCInit();
     IntMasterIRQEnable();

lib/pbio/platform/ev3/platform.ld

@@ -8,6 +8,7 @@ MEMORY
     SRAM       (rwx) : ORIGIN = 0x80000000, LENGTH = 128K
     DDR_unused (rwx) : ORIGIN = 0xC0000000, LENGTH = 0x8000
     DDR        (rwx) : ORIGIN = 0xC0008000, LENGTH = (64M - 0x8000)
+    ARM_LRAM   (rwx) : ORIGIN = 0xFFFF0000, LENGTH = 8K
 }
 
 _minimal_stack_size = 4M;
@@ -53,6 +54,13 @@ SECTIONS
         *(.noinit)
     } > DDR
 
+    /* Exception vector table */
+    .vector :
+    {
+        . = ALIGN(4);
+        KEEP(*(.vector));
+    } > ARM_LRAM
+
     .stack :
     {
         . = ALIGN(4);