[U-Boot] [PATCH v1 7/7] MIPS: add dynamic relocation support
daniel.schwierzeck at gmail.com
daniel.schwierzeck at gmail.com
Sat Feb 9 21:33:30 CET 2013
From: Gabor Juhos <juhosg at openwrt.org>
The code handles relocation entries with the
following relocation types only:
mips32: R_MIPS_REL32
mips64: R_MIPS_REL+R_MIPS_64
xburst: R_MIPS_REL32
Other relocation entries are skipped without
processing. The code must be extended if other
relocation types must be supported.
Add -pie to LDFLAGS_FINAL to generate the .rel.dyn
fixup table, which will be applied to the relocated
image before transferring control to it.
The CONFIG_NEEDS_MANUAL_RELOC is not needed
after the patch, so remove that as well.
Signed-off-by: Gabor Juhos <juhosg at openwrt.org>
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
---
arch/mips/config.mk | 3 ++-
arch/mips/cpu/mips32/start.S | 28 ++++++++++++++++++++++++++++
arch/mips/cpu/mips64/start.S | 36 ++++++++++++++++++++++++++++++++++++
arch/mips/cpu/xburst/start.S | 28 ++++++++++++++++++++++++++++
arch/mips/include/asm/config.h | 2 --
arch/mips/lib/board.c | 9 ---------
6 files changed, 94 insertions(+), 12 deletions(-)
diff --git a/arch/mips/config.mk b/arch/mips/config.mk
index de9140b..aaa94e8 100644
--- a/arch/mips/config.mk
+++ b/arch/mips/config.mk
@@ -65,4 +65,5 @@ PLATFORM_CPPFLAGS += -G 0 -mabicalls -fpic $(ENDIANNESS)
PLATFORM_CPPFLAGS += -msoft-float
PLATFORM_LDFLAGS += -G 0 -static -n -nostdlib $(ENDIANNESS)
PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections
-LDFLAGS_FINAL += --gc-sections
+LDFLAGS_FINAL += --gc-sections -pie
+OBJCFLAGS += --remove-section=.dynsym
diff --git a/arch/mips/cpu/mips32/start.S b/arch/mips/cpu/mips32/start.S
index 649c0bb..76abbaa 100644
--- a/arch/mips/cpu/mips32/start.S
+++ b/arch/mips/cpu/mips32/start.S
@@ -201,6 +201,8 @@ relocate_code:
jr t0
nop
+ .word __rel_dyn_end
+ .word __rel_dyn_start
.word __image_copy_end
.word _GLOBAL_OFFSET_TABLE_
.word num_got_entries
@@ -227,6 +229,32 @@ in_ram:
blt t2, t3, 1b
addi t4, 4
+ /* Update dynamic relocations */
+ lw t1, -16(t0) # t1 <-- __rel_dyn_start
+ lw t2, -20(t0) # t2 <-- __rel_dyn_end
+
+ b 2f # skip first reserved entry
+ addi t1, 8
+
+1:
+ lw t3, -4(t1) # t3 <-- relocation info
+
+ sub t3, 3
+ bnez t3, 2f # skip non R_MIPS_REL32 entries
+ nop
+
+ lw t3, -8(t1) # t3 <-- location to fix up in FLASH
+
+ lw t4, 0(t3) # t4 <-- original pointer
+ add t4, s1 # t4 <-- adjusted pointer
+
+ add t3, s1 # t3 <-- location to fix up in RAM
+ sw t4, 0(t3)
+
+2:
+ blt t1, t2, 1b
+ addi t1, 8 # each rel.dyn entry is 8 bytes
+
/*
* Clear BSS
*
diff --git a/arch/mips/cpu/mips64/start.S b/arch/mips/cpu/mips64/start.S
index 5c2c7b5..dc7ce07 100644
--- a/arch/mips/cpu/mips64/start.S
+++ b/arch/mips/cpu/mips64/start.S
@@ -31,6 +31,14 @@
#define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT
#endif
+#ifdef CONFIG_SYS_LITTLE_ENDIAN
+#define MIPS64_R_INFO(ssym, r_type3, r_type2, r_type) \
+ (((r_type) << 24) | ((r_type2) << 16) | ((r_type3) << 8) | (ssym))
+#else
+#define MIPS64_R_INFO(ssym, r_type3, r_type2, r_type) \
+ ((r_type) | ((r_type2) << 8) | ((r_type3) << 16) | (ssym) << 24)
+#endif
+
/*
* For the moment disable interrupts, mark the kernel mode and
* set ST0_KX so that the CPU does not spit fire when using
@@ -193,6 +201,8 @@ relocate_code:
jr t0
nop
+ .dword __rel_dyn_end
+ .dword __rel_dyn_start
.dword __image_copy_end
.dword _GLOBAL_OFFSET_TABLE_
.dword num_got_entries
@@ -219,6 +229,32 @@ in_ram:
blt t2, t3, 1b
daddi t8, 8
+ /* Update dynamic relocations */
+ ld t1, -32(t0) # t1 <-- __rel_dyn_start
+ ld t2, -40(t0) # t2 <-- __rel_dyn_end
+
+ b 2f # skip first reserved entry
+ daddi t1, 16
+
+1:
+ lw t8, -4(t1) # t8 <-- relocation info
+
+ dli t3, MIPS64_R_INFO(0x00, 0x00, 0x12, 0x03)
+ bne t8, t3, 2f # skip non R_MIPS_REL32 entries
+ nop
+
+ ld t3, -16(t1) # t3 <-- location to fix up in FLASH
+
+ ld t8, 0(t3) # t8 <-- original pointer
+ dadd t8, s1 # t8 <-- adjusted pointer
+
+ dadd t3, s1 # t3 <-- location to fix up in RAM
+ sd t8, 0(t3)
+
+2:
+ blt t1, t2, 1b
+ daddi t1, 16 # each rel.dyn entry is 16 bytes
+
/*
* Clear BSS
*
diff --git a/arch/mips/cpu/xburst/start.S b/arch/mips/cpu/xburst/start.S
index 6b30d3e..d2c064b 100644
--- a/arch/mips/cpu/xburst/start.S
+++ b/arch/mips/cpu/xburst/start.S
@@ -116,6 +116,8 @@ relocate_code:
jr t0
nop
+ .word __rel_dyn_end
+ .word __rel_dyn_start
.word __image_copy_end
.word _GLOBAL_OFFSET_TABLE_
.word num_got_entries
@@ -142,6 +144,32 @@ in_ram:
blt t2, t3, 1b
addi t4, 4
+ /* Update dynamic relocations */
+ lw t1, -16(t0) # t1 <-- __rel_dyn_start
+ lw t2, -20(t0) # t2 <-- __rel_dyn_end
+
+ b 2f # skip first reserved entry
+ addi t1, 8
+
+1:
+ lw t3, -4(t1) # t3 <-- relocation info
+
+ sub t3, 3
+ bnez t3, 2f # skip non R_MIPS_REL32 entries
+ nop
+
+ lw t3, -8(t1) # t3 <-- location to fix up in FLASH
+
+ lw t4, 0(t3) # t4 <-- original pointer
+ add t4, t6 # t4 <-- adjusted pointer
+
+ add t3, t6 # t3 <-- location to fix up in RAM
+ sw t4, 0(t3)
+
+2:
+ blt t1, t2, 1b
+ addi t1, 8 # each rel.dyn entry is 8 bytes
+
/*
* Clear BSS
*
diff --git a/arch/mips/include/asm/config.h b/arch/mips/include/asm/config.h
index 02fbfb3..049c44e 100644
--- a/arch/mips/include/asm/config.h
+++ b/arch/mips/include/asm/config.h
@@ -21,6 +21,4 @@
#ifndef _ASM_CONFIG_H_
#define _ASM_CONFIG_H_
-#define CONFIG_NEEDS_MANUAL_RELOC
-
#endif
diff --git a/arch/mips/lib/board.c b/arch/mips/lib/board.c
index d494876..2ec0f76 100644
--- a/arch/mips/lib/board.c
+++ b/arch/mips/lib/board.c
@@ -266,14 +266,6 @@ void board_init_r(gd_t *id, ulong dest_addr)
serial_initialize();
-#if defined(CONFIG_NEEDS_MANUAL_RELOC)
- /*
- * We have to relocate the command table manually
- */
- fixup_cmdtable(ll_entry_start(cmd_tbl_t, cmd),
- ll_entry_count(cmd_tbl_t, cmd));
-#endif /* defined(CONFIG_NEEDS_MANUAL_RELOC) */
-
/* there are some other pointer constants we must deal with */
#ifndef CONFIG_ENV_IS_NOWHERE
env_name_spec += gd->reloc_off;
@@ -284,7 +276,6 @@ void board_init_r(gd_t *id, ulong dest_addr)
/* The Malloc area is immediately below the monitor copy in DRAM */
mem_malloc_init(CONFIG_SYS_MONITOR_BASE + gd->reloc_off -
TOTAL_MALLOC_LEN, TOTAL_MALLOC_LEN);
- malloc_bin_reloc();
#ifndef CONFIG_SYS_NO_FLASH
/* configure available FLASH banks */
--
1.8.1.1
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