microblaze: start.S: Factor out exception setup code to __setup_exceptions

Currently, the exceptions setup code is duplicated in pre-relocation and
post-relocation init. Factor out this code to __setup_exceptions asm
routine to get rid of the duplication.

__setup_exceptions is called with a relocation offset parameter (r5)
which is set to zero for pre-reloc init and gd->reloc_off for post-reloc
exception setup.

Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/arch/microblaze/cpu/start.S b/arch/microblaze/cpu/start.S
index cbec299..b9c6ccc 100644 (file)
--- a/arch/microblaze/cpu/start.S
+++ b/arch/microblaze/cpu/start.S
@@ -13,13 +13,6 @@
        .text
        .global _start
 _start:
-       /*
-        * reserve registers:
-        * r10: Stores little/big endian offset for vectors
-        * r2: Stores imm opcode
-        * r3: Stores brai opcode
-        */
-
        mts     rmsr, r0        /* disable cache */
 
        addi    r8, r0, __end
@@ -38,6 +31,92 @@ _start:
        mts     rshr, r1
        addi    r1, r1, -4      /* Decrement SP to top of memory */
 
+       /* Setup vectors with pre-relocation symbols */
+       or      r5, r0, r0
+       bralid  r15, __setup_exceptions
+       nop
+#endif /* CONFIG_SPL_BUILD */
+
+       /* Flush cache before enable cache */
+       addik   r5, r0, 0
+       addik   r6, r0, XILINX_DCACHE_BYTE_SIZE
+       bralid  r15, flush_cache
+       nop
+
+       /* enable instruction and data cache */
+       mfs     r12, rmsr
+       ori     r12, r12, 0x1a0
+       mts     rmsr, r12
+
+       /* TODO: Redo this code to call board_init_f_*() */
+clear_bss:
+       /* clear BSS segments */
+       addi    r5, r0, __bss_start
+       addi    r4, r0, __bss_end
+       cmp     r6, r5, r4
+       beqi    r6, 3f
+2:
+       swi     r0, r5, 0 /* write zero to loc */
+       addi    r5, r5, 4 /* increment to next loc */
+       cmp     r6, r5, r4 /* check if we have reach the end */
+       bnei    r6, 2b
+3:     /* jumping to board_init */
+#ifdef CONFIG_DEBUG_UART
+       bralid  r15, debug_uart_init
+       nop
+#endif
+#ifndef CONFIG_SPL_BUILD
+       or      r5, r0, r0      /* flags - empty */
+       addi    r31, r0, _gd
+#if CONFIG_VAL(SYS_MALLOC_F_LEN)
+       addi    r6, r0, CONFIG_SYS_INIT_SP_OFFSET
+       swi     r6, r31, GD_MALLOC_BASE
+#endif
+       brai    board_init_f
+#else
+       addi    r31, r0, _gd
+#if CONFIG_VAL(SYS_MALLOC_F_LEN)
+       addi    r6, r0, CONFIG_SPL_STACK_ADDR
+       swi     r6, r31, GD_MALLOC_BASE
+#endif
+       brai    board_init_r
+#endif
+1:     bri     1b
+
+ .section .bss
+.align 4
+_gd:
+         .space  GENERATED_GBL_DATA_SIZE
+
+#ifndef CONFIG_SPL_BUILD
+       .text
+       .ent    __setup_exceptions
+       .align  2
+/*
+ * Set up reset, interrupt, user exception and hardware exception vectors.
+ *
+ * Parameters:
+ * r5 - relocation offset (zero when setting up vectors before
+ *      relocation, and gd->reloc_off when setting up vectors after
+ *      relocation)
+ *    - the relocation offset is added to the _exception_handler,
+ *      _interrupt_handler and _hw_exception_handler symbols to reflect the
+ *      post-relocation memory addresses
+ *
+ * Reserve registers:
+ * r10: Stores little/big endian offset for vectors
+ * r2: Stores imm opcode
+ * r3: Stores brai opcode
+ */
+__setup_exceptions:
+       addik   r1, r1, -28
+       swi     r2, r1, 4
+       swi     r3, r1, 8
+       swi     r6, r1, 12
+       swi     r7, r1, 16
+       swi     r8, r1, 20
+       swi     r10, r1, 24
+
        /* Find-out if u-boot is running on BIG/LITTLE endian platform
         * There are some steps which is necessary to keep in mind:
         * 1. Setup offset value to r6
@@ -76,7 +155,7 @@ _start:
        swi     r2, r0, 0x8     /* user vector exception - imm opcode */
        swi     r3, r0, 0xC     /* user vector exception - brai opcode */
 
-       addik   r6, r0, _exception_handler
+       addik   r6, r5, _exception_handler
        sw      r6, r1, r0
        /*
         * BIG ENDIAN memory map for user exception
@@ -109,7 +188,7 @@ _start:
        swi     r2, r0, 0x10    /* interrupt - imm opcode */
        swi     r3, r0, 0x14    /* interrupt - brai opcode */
 
-       addik   r6, r0, _interrupt_handler
+       addik   r6, r5, _interrupt_handler
        sw      r6, r1, r0
        lhu     r7, r1, r10
        rsubi   r8, r10, 0x12
@@ -121,67 +200,26 @@ _start:
        swi     r2, r0, 0x20    /* hardware exception - imm opcode */
        swi     r3, r0, 0x24    /* hardware exception - brai opcode */
 
-       addik   r6, r0, _hw_exception_handler
+       addik   r6, r5, _hw_exception_handler
        sw      r6, r1, r0
        lhu     r7, r1, r10
        rsubi   r8, r10, 0x22
        sh      r7, r0, r8
        rsubi   r8, r10, 0x26
        sh      r6, r0, r8
-#endif /* CONFIG_SPL_BUILD */
-
-       /* Flush cache before enable cache */
-       addik   r5, r0, 0
-       addik   r6, r0, XILINX_DCACHE_BYTE_SIZE
-       bralid r15, flush_cache
-       nop
-
-       /* enable instruction and data cache */
-       mfs     r12, rmsr
-       ori     r12, r12, 0x1a0
-       mts     rmsr, r12
 
-       /* TODO: Redo this code to call board_init_f_*() */
-clear_bss:
-       /* clear BSS segments */
-       addi    r5, r0, __bss_start
-       addi    r4, r0, __bss_end
-       cmp     r6, r5, r4
-       beqi    r6, 3f
-2:
-       swi     r0, r5, 0 /* write zero to loc */
-       addi    r5, r5, 4 /* increment to next loc */
-       cmp     r6, r5, r4 /* check if we have reach the end */
-       bnei    r6, 2b
-3:     /* jumping to board_init */
-#ifdef CONFIG_DEBUG_UART
-       bralid  r15, debug_uart_init
-       nop
-#endif
-#ifndef CONFIG_SPL_BUILD
-       or      r5, r0, r0      /* flags - empty */
-       addi    r31, r0, _gd
-#if CONFIG_VAL(SYS_MALLOC_F_LEN)
-       addi    r6, r0, CONFIG_SYS_INIT_SP_OFFSET
-       swi     r6, r31, GD_MALLOC_BASE
-#endif
-       brai    board_init_f
-#else
-       addi    r31, r0, _gd
-#if CONFIG_VAL(SYS_MALLOC_F_LEN)
-       addi    r6, r0, CONFIG_SPL_STACK_ADDR
-       swi     r6, r31, GD_MALLOC_BASE
-#endif
-       brai    board_init_r
-#endif
-1:     bri     1b
+       lwi     r10, r1, 24
+       lwi     r8, r1, 20
+       lwi     r7, r1, 16
+       lwi     r6, r1, 12
+       lwi     r3, r1, 8
+       lwi     r2, r1, 4
+       addik   r1, r1, 28
 
- .section .bss
-.align 4
-_gd:
-         .space  GENERATED_GBL_DATA_SIZE
+       rtsd    r15, 8
+       or      r0, r0, r0
+       .end    __setup_exceptions
 
-#ifndef CONFIG_SPL_BUILD
 /*
  * Read 16bit little endian
  */
@@ -249,39 +287,10 @@ relocate_code:
        addi    r24, r0, CONFIG_SYS_TEXT_BASE /* Get reloc offset */
        rsub    r23, r24, r23 /* keep - this is already here gd->reloc_off */
 
-       addik   r6, r0, 0x2 /* BIG/LITTLE endian offset */
-       lwi     r7, r0, 0x28
-       swi     r6, r0, 0x28 /* used first unused MB vector */
-       lbui    r10, r0, 0x28 /* used first unused MB vector */
-       swi     r7, r0, 0x28
-
-#ifdef CONFIG_SYS_USR_EXCEP
-       addik   r6, r0, _exception_handler
-       addk    r6, r6, r23 /* add offset */
-       sw      r6, r1, r0
-       lhu     r7, r1, r10
-       rsubi   r8, r10, 0xa
-       sh      r7, r0, r8
-       rsubi   r8, r10, 0xe
-       sh      r6, r0, r8
-#endif
-       addik   r6, r0, _hw_exception_handler
-       addk    r6, r6, r23 /* add offset */
-       sw      r6, r1, r0
-       lhu     r7, r1, r10
-       rsubi   r8, r10, 0x22
-       sh      r7, r0, r8
-       rsubi   r8, r10, 0x26
-       sh      r6, r0, r8
-
-       addik   r6, r0, _interrupt_handler
-       addk    r6, r6, r23 /* add offset */
-       sw      r6, r1, r0
-       lhu     r7, r1, r10
-       rsubi   r8, r10, 0x12
-       sh      r7, r0, r8
-       rsubi   r8, r10, 0x16
-       sh      r6, r0, r8
+       /* Setup vectors with post-relocation symbols */
+       add     r5, r0, r23 /* load gd->reloc_off to r5 */
+       bralid  r15, __setup_exceptions
+       nop
 
        /* Check if GOT exist */
        addik   r21, r23, _got_start