[PATCH v3 1/2] firmware: remove copy-base relocation
Xiang W
wxjstz at 126.com
Tue Mar 12 01:24:59 PDT 2024
Remove copy-base relocations that are no longer needed.
Signed-off-by: Xiang W <wxjstz at 126.com>
Reviewed-by: Samuel Holland <samuel.holland at sifive.com>
Tested-by: Samuel Holland <samuel.holland at sifive.com>
---
Makefile | 8 +++-
README.md | 3 +-
docs/firmware/fw.md | 6 ---
firmware/fw_base.S | 98 ++-------------------------------------------
firmware/objects.mk | 11 -----
5 files changed, 11 insertions(+), 115 deletions(-)
diff --git a/Makefile b/Makefile
index 680c19a..50f634e 100644
--- a/Makefile
+++ b/Makefile
@@ -179,6 +179,10 @@ CC_SUPPORT_STRICT_ALIGN := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib
# Check whether the assembler and the compiler support the Zicsr and Zifencei extensions
CC_SUPPORT_ZICSR_ZIFENCEI := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib -march=rv$(OPENSBI_CC_XLEN)imafd_zicsr_zifencei -x c /dev/null -o /dev/null 2>&1 | grep "zicsr\|zifencei" > /dev/null && echo n || echo y)
+ifneq ($(OPENSBI_LD_PIE),y)
+$(error Your linker does not support creating PIEs, opensbi requires this.)
+endif
+
# Build Info:
# OPENSBI_BUILD_TIME_STAMP -- the compilation time stamp
# OPENSBI_BUILD_COMPILER_VERSION -- the compiler version info
@@ -356,7 +360,7 @@ CFLAGS += -mcmodel=$(PLATFORM_RISCV_CODE_MODEL)
CFLAGS += $(RELAX_FLAG)
CFLAGS += $(GENFLAGS)
CFLAGS += $(platform-cflags-y)
-CFLAGS += -fno-pie -no-pie
+CFLAGS += -fPIE -pie
CFLAGS += $(firmware-cflags-y)
CPPFLAGS += $(GENFLAGS)
@@ -365,6 +369,7 @@ CPPFLAGS += $(firmware-cppflags-y)
ASFLAGS = -g -Wall -nostdlib
ASFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
+ASFLAGS += -fPIE
# Optionally supported flags
ifeq ($(CC_SUPPORT_SAVE_RESTORE),y)
ASFLAGS += -mno-save-restore
@@ -391,6 +396,7 @@ ifeq ($(OPENSBI_LD_EXCLUDE_LIBS),y)
ELFFLAGS += -Wl,--exclude-libs,ALL
endif
ELFFLAGS += -Wl,--build-id=none
+ELFFLAGS += -Wl,--no-dynamic-linker -Wl,-pie
ELFFLAGS += $(platform-ldflags-y)
ELFFLAGS += $(firmware-ldflags-y)
diff --git a/README.md b/README.md
index 73de8ea..cbae73a 100644
--- a/README.md
+++ b/README.md
@@ -276,8 +276,7 @@ document.
NOTE: Using Clang with a `riscv*-linux-gnu` GNU binutils linker has been seen
to produce broken binaries with missing relocations; it is therefore currently
-recommended that this combination be avoided or *FW_PIC=n* be used to disable
-building OpenSBI as a position-independent binary.
+recommended that this combination be avoided.
Building with timestamp and compiler info
-----------------------------------------
diff --git a/docs/firmware/fw.md b/docs/firmware/fw.md
index 38351c8..2f4deb5 100644
--- a/docs/firmware/fw.md
+++ b/docs/firmware/fw.md
@@ -69,12 +69,6 @@ parameters:
argument by the prior booting stage.
* **FW_FDT_PADDING** - Optional zero bytes padding to the embedded flattened
device tree binary file specified by **FW_FDT_PATH** option.
-* **FW_PIC** - "FW_PIC=y" generates position independent executable firmware
- images. OpenSBI can run at arbitrary address with appropriate alignment.
- Therefore, the original relocation mechanism ("FW_PIC=n") will be skipped.
- In other words, OpenSBI will directly run at the load address without any
- code movement. This option requires a toolchain with PIE support, and it
- is on by default.
Additionally, each firmware type as a set of type specific configuration
parameters. Detailed information for each firmware type can be found in the
diff --git a/firmware/fw_base.S b/firmware/fw_base.S
index 126b067..6013db3 100644
--- a/firmware/fw_base.S
+++ b/firmware/fw_base.S
@@ -15,8 +15,7 @@
#include <sbi/sbi_trap.h>
#define BOOT_STATUS_LOTTERY_DONE 1
-#define BOOT_STATUS_RELOCATE_DONE 2
-#define BOOT_STATUS_BOOT_HART_DONE 3
+#define BOOT_STATUS_BOOT_HART_DONE 2
.macro MOV_3R __d0, __s0, __d1, __s1, __d2, __s2
add \__d0, \__s0, zero
@@ -32,17 +31,6 @@
add \__d4, \__s4, zero
.endm
-/*
- * If __start_reg <= __check_reg and __check_reg < __end_reg then
- * jump to __pass
- */
-.macro BRANGE __start_reg, __end_reg, __check_reg, __jump_lable
- blt \__check_reg, \__start_reg, 999f
- bge \__check_reg, \__end_reg, 999f
- j \__jump_lable
-999:
-.endm
-
.section .entry, "ax", %progbits
.align 3
.globl _start
@@ -56,15 +44,14 @@ _start:
li a7, -1
beq a6, a7, _try_lottery
/* Jump to relocation wait loop if we are not boot hart */
- bne a0, a6, _wait_relocate_copy_done
+ bne a0, a6, _wait_for_boot_hart
_try_lottery:
/* Jump to relocation wait loop if we don't get relocation lottery */
lla a6, _boot_status
li a7, BOOT_STATUS_LOTTERY_DONE
amoswap.w a6, a7, (a6)
- bnez a6, _wait_relocate_copy_done
+ bnez a6, _wait_for_boot_hart
-#ifdef FW_PIC
/* relocate the global table content */
li t0, FW_TEXT_START /* link start */
lla t1, _fw_start /* load start */
@@ -85,86 +72,7 @@ _try_lottery:
3:
addi t0, t0, (REGBYTES * 3)
blt t0, t1, 2b
- j _relocate_done
-_wait_relocate_copy_done:
- j _wait_for_boot_hart
-#else
- /* Relocate if load address != link address */
-_relocate:
- li t0, FW_TEXT_START /* link start */
- lla t2, _fw_start /* load start */
- lla t3, _fw_reloc_end /* load end */
- sub t6, t2, t0 /* load offset */
- sub t1, t3, t6 /* link end */
- beq t0, t2, _relocate_done
- lla t4, _relocate_done
- sub t4, t4, t6
- blt t2, t0, _relocate_copy_to_upper
-_relocate_copy_to_lower:
- ble t1, t2, _relocate_copy_to_lower_loop
- lla t3, _boot_status
- BRANGE t2, t1, t3, _start_hang
- lla t3, _relocate
- lla t5, _relocate_done
- BRANGE t2, t1, t3, _start_hang
- BRANGE t2, t1, t5, _start_hang
- BRANGE t3, t5, t2, _start_hang
-_relocate_copy_to_lower_loop:
- REG_L t3, 0(t2)
- REG_S t3, 0(t0)
- add t0, t0, __SIZEOF_POINTER__
- add t2, t2, __SIZEOF_POINTER__
- blt t0, t1, _relocate_copy_to_lower_loop
- jr t4
-_relocate_copy_to_upper:
- ble t3, t0, _relocate_copy_to_upper_loop
- lla t2, _boot_status
- BRANGE t0, t3, t2, _start_hang
- lla t2, _relocate
- lla t5, _relocate_done
- BRANGE t0, t3, t2, _start_hang
- BRANGE t0, t3, t5, _start_hang
- BRANGE t2, t5, t0, _start_hang
-_relocate_copy_to_upper_loop:
- add t3, t3, -__SIZEOF_POINTER__
- add t1, t1, -__SIZEOF_POINTER__
- REG_L t2, 0(t3)
- REG_S t2, 0(t1)
- blt t0, t1, _relocate_copy_to_upper_loop
- jr t4
-_wait_relocate_copy_done:
- lla t0, _fw_start
- li t1, FW_TEXT_START
- beq t0, t1, _wait_for_boot_hart
- lla t2, _boot_status
- lla t3, _wait_for_boot_hart
- sub t3, t3, t0
- add t3, t3, t1
-1:
- /* waitting for relocate copy done (_boot_status == 1) */
- li t4, BOOT_STATUS_RELOCATE_DONE
- REG_L t5, 0(t2)
- /* Reduce the bus traffic so that boot hart may proceed faster */
- nop
- nop
- nop
- bgt t4, t5, 1b
- jr t3
-#endif
_relocate_done:
-
- /*
- * Mark relocate copy done
- * Use _boot_status copy relative to the load address
- */
- lla t0, _boot_status
-#ifndef FW_PIC
- add t0, t0, t6
-#endif
- li t1, BOOT_STATUS_RELOCATE_DONE
- REG_S t1, 0(t0)
- fence rw, rw
-
/* At this point we are running from link address */
/* Reset all registers except ra, a0, a1, a2, a3 and a4 for boot HART */
diff --git a/firmware/objects.mk b/firmware/objects.mk
index 3ae0a28..e6b364b 100644
--- a/firmware/objects.mk
+++ b/firmware/objects.mk
@@ -13,17 +13,6 @@ firmware-cflags-y +=
firmware-asflags-y +=
firmware-ldflags-y +=
-ifndef FW_PIC
-FW_PIC := $(OPENSBI_LD_PIE)
-endif
-
-ifeq ($(FW_PIC),y)
-firmware-genflags-y += -DFW_PIC
-firmware-asflags-y += -fpic
-firmware-cflags-y += -fPIE -pie
-firmware-ldflags-y += -Wl,--no-dynamic-linker -Wl,-pie
-endif
-
ifdef FW_TEXT_START
firmware-genflags-y += -DFW_TEXT_START=$(FW_TEXT_START)
endif
--
2.43.0
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