[PATCH v2 1/2] microblaze: start.S: Factor out exception setup code to __setup_exceptions
Ovidiu Panait
ovidiu.panait at windriver.com
Thu Sep 24 10:54:36 CEST 2020
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 at monstr.eu>
Signed-off-by: Ovidiu Panait <ovidiu.panait at windriver.com>
---
v2:
- fix coding style
- save r2/r3/r6/r7/r8/r10 on the stack when entering __setup_exceptions
arch/microblaze/cpu/start.S | 197 +++++++++++++++++++-----------------
1 file changed, 103 insertions(+), 94 deletions(-)
diff --git a/arch/microblaze/cpu/start.S b/arch/microblaze/cpu/start.S
index cbec299b7d..b9c6ccc912 100644
--- 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
--
2.25.1
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