[PATCH v2 1/4] firmware: Add relocatable FW_JUMP_ADDR and FW_JUMP_FDT_ADDR

[Inochi Amaoto]

If FW_PIC=y is defined, the fw_jump.bin will be broken if
FW_TEXT_START is wrong. This is not the desired behavior.

Add two new variables to identify relocatable jump address:
FW_JUMP_OFFSET and FW_JUMP_FDT_ADDR. To keep the existing
ABI, FW_JUMP_ADDR and FW_JUMP_FDT_ADDR is prefered if they
are defined.

Signed-off-by: Inochi Amaoto <inochiama at outlook.com>
---
 firmware/fw_jump.S  | 18 ++++++++++++++----
 firmware/objects.mk |  6 ++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/firmware/fw_jump.S b/firmware/fw_jump.S
index ac74dc6..ebf297f 100644
--- a/firmware/fw_jump.S
+++ b/firmware/fw_jump.S
@@ -46,6 +46,10 @@ fw_save_info:
 fw_next_arg1:
 #ifdef FW_JUMP_FDT_ADDR
 	li	a0, FW_JUMP_FDT_ADDR
+#elif defined(FW_JUMP_FDT_OFFSET)
+	lla	a0, _fw_start
+	li	a1, FW_JUMP_FDT_OFFSET
+	add	a0, a0, a1
 #else
 	add	a0, a1, zero
 #endif
@@ -59,8 +63,16 @@ fw_next_arg1:
 	 * The next address should be returned in 'a0'.
 	 */
 fw_next_addr:
+#ifdef FW_JUMP_ADDR
 	lla	a0, _jump_addr
 	REG_L	a0, (a0)
+#elif defined(FW_JUMP_OFFSET)
+	lla	a0, _fw_start
+	li	a1, FW_JUMP_OFFSET
+	add	a0, a0, a1
+#else
+#error "Must define at least FW_JUMP_ADDR or FW_JUMP_OFFSET"
+#endif
 	ret
 
 	.section .entry, "ax", %progbits
@@ -86,11 +98,9 @@ fw_options:
 	add	a0, zero, zero
 	ret
 
-#ifndef FW_JUMP_ADDR
-#error "Must define FW_JUMP_ADDR"
-#endif
-
+#ifdef FW_JUMP_ADDR
 	.section .rodata
 	.align 3
 _jump_addr:
 	RISCV_PTR FW_JUMP_ADDR
+#endif
diff --git a/firmware/objects.mk b/firmware/objects.mk
index a1704c4..fef090a 100644
--- a/firmware/objects.mk
+++ b/firmware/objects.mk
@@ -38,9 +38,15 @@ endif
 firmware-bins-$(FW_DYNAMIC) += fw_dynamic.bin
 
 firmware-bins-$(FW_JUMP) += fw_jump.bin
+ifdef FW_JUMP_OFFSET
+firmware-genflags-$(FW_JUMP) += -DFW_JUMP_OFFSET=$(FW_JUMP_OFFSET)
+endif
 ifdef FW_JUMP_ADDR
 firmware-genflags-$(FW_JUMP) += -DFW_JUMP_ADDR=$(FW_JUMP_ADDR)
 endif
+ifdef FW_JUMP_FDT_OFFSET
+firmware-genflags-$(FW_JUMP) += -DFW_JUMP_FDT_OFFSET=$(FW_JUMP_FDT_OFFSET)
+endif
 ifdef FW_JUMP_FDT_ADDR
 firmware-genflags-$(FW_JUMP) += -DFW_JUMP_FDT_ADDR=$(FW_JUMP_FDT_ADDR)
 endif
-- 
2.43.2