firmware: remove copy-base relocation

Remove copy-base relocations that are no longer needed.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

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)
 

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
+recommended that this combination be avoided.
-building OpenSBI as a position-independent binary.
 
 Building with timestamp and compiler info
 -----------------------------------------

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

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	2
-#define BOOT_STATUS_BOOT_HART_DONE	3
 
 .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 */

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