From 331f291e4cff8f0b7b35edded21132c2fa69fb97 Mon Sep 17 00:00:00 2001
From: Anup Patel <anup.patel@wdc.com>
Date: Fri, 7 Jun 2019 20:26:55 +0530
Subject: firmware: Relocate when load address is not equal to link address
This patch extends fw_base to relocate to link address whenever
firmware load address is not equal to link address.
The relocation will not work when load start to load end overlap
link start to link end.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
---
firmware/fw_base.S | 53 ++++++++++++++++++++++++++++++++++++++++-----
firmware/fw_dynamic.elf.ldS | 2 ++
firmware/fw_jump.elf.ldS | 2 ++
firmware/fw_payload.elf.ldS | 2 ++
4 files changed, 53 insertions(+), 6 deletions(-)
(limited to 'firmware')
diff --git a/firmware/fw_base.S b/firmware/fw_base.S
index 0d7cf69..1a3c760 100644
--- a/firmware/fw_base.S
+++ b/firmware/fw_base.S
@@ -39,6 +39,33 @@ _start:
csrr a6, CSR_MHARTID
blt zero, a6, _wait_for_boot_hart
+ /* Save load address */
+ la t0, _load_start
+ la t1, _start
+ REG_S t1, 0(t0)
+
+ /* Relocate if load address != link address */
+ la t0, _link_start
+ REG_L t0, 0(t0)
+ la t1, _link_end
+ REG_L t1, 0(t1)
+ la t2, _load_start
+ REG_L t2, 0(t2)
+ beq t0, t2, _relocate_done
+ la t4, _relocate_done
+ sub t4, t4, t2
+ add t4, t4, t0
+_relocate_copy:
+ 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
+ jr t4
+_relocate_done:
+
+ /* At this point we are running from link address */
+
/* Reset all registers for boot HART */
li ra, 0
call _reset_regs
@@ -209,18 +236,29 @@ _fdt_reloc_done:
/* Update boot hart flag */
la a4, _boot_hart_done
- li a5, 1
+ la a5, _start_warm
REG_S a5, (a4)
+ fence rw, rw
+ la t0, _link_start
+ REG_L t0, 0(t0)
+ sub a4, a4, t0
+ la t0, _load_start
+ REG_L t0, 0(t0)
+ add a4, a4, t0
+ REG_S a5, (a4)
+ fence rw, rw
+ j _start_warm
/* Wait for boot hart */
_wait_for_boot_hart:
la a4, _boot_hart_done
- REG_L a5, (a4)
+ REG_L a5, 0(a4)
/* Reduce the bus traffic so that boot hart may proceed faster */
nop
nop
nop
beqz a5, _wait_for_boot_hart
+ jr a5
_start_warm:
/* Reset all registers for non-boot HARTs */
@@ -263,11 +301,9 @@ _start_warm:
la a4, _trap_handler
csrw CSR_MTVEC, a4
/* Make sure that mtvec is updated */
- 1:
- csrr a5, CSR_MTVEC
+1: csrr a5, CSR_MTVEC
bne a4, a5, 1b
-
/* Initialize SBI runtime */
csrr a0, CSR_MSCRATCH
call sbi_init
@@ -276,9 +312,14 @@ _start_warm:
j _start_hang
.align 3
- .section .data, "aw"
_boot_hart_done:
RISCV_PTR 0
+_load_start:
+ RISCV_PTR _fw_start
+_link_start:
+ RISCV_PTR _fw_start
+_link_end:
+ RISCV_PTR _fw_reloc_end
.align 3
.section .entry, "ax", %progbits
diff --git a/firmware/fw_dynamic.elf.ldS b/firmware/fw_dynamic.elf.ldS
index 7ee0787..d1e2ea8 100644
--- a/firmware/fw_dynamic.elf.ldS
+++ b/firmware/fw_dynamic.elf.ldS
@@ -13,4 +13,6 @@ ENTRY(_start)
SECTIONS
{
#include "fw_base.ldS"
+
+ PROVIDE(_fw_reloc_end = .);
}
diff --git a/firmware/fw_jump.elf.ldS b/firmware/fw_jump.elf.ldS
index 7ee0787..d1e2ea8 100644
--- a/firmware/fw_jump.elf.ldS
+++ b/firmware/fw_jump.elf.ldS
@@ -13,4 +13,6 @@ ENTRY(_start)
SECTIONS
{
#include "fw_base.ldS"
+
+ PROVIDE(_fw_reloc_end = .);
}
diff --git a/firmware/fw_payload.elf.ldS b/firmware/fw_payload.elf.ldS
index 44fa4c3..f1a544b 100644
--- a/firmware/fw_payload.elf.ldS
+++ b/firmware/fw_payload.elf.ldS
@@ -27,4 +27,6 @@ SECTIONS
. = ALIGN(8);
PROVIDE(_payload_end = .);
}
+
+ PROVIDE(_fw_reloc_end = .);
}
--
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