firmware/fw_payload: reduce the size by getting rid of padding

Signed-off-by: Tekkaman Ninja <tekkamanninja@163.com>

firmware/fw_payload.S

@@ -20,6 +20,13 @@
 	 */
 fw_boot_hart:
 	li	a0, -1
+#ifdef FW_PAYLOAD_NOPAD
+
+#include "fw_reloc_payload.S"
+
+	.globl _relocate_payload_done
+_relocate_payload_done:
+#endif
 	ret
 
 	.section .entry, "ax", %progbits
@@ -59,7 +66,11 @@ fw_next_arg1:
 	 * The next address should be returned in 'a0'.
 	 */
 fw_next_addr:
+#ifdef FW_PAYLOAD_NOPAD
+	li	a0, (FW_TEXT_START + FW_PAYLOAD_OFFSET)
+#else
 	lla	a0, payload_bin
+#endif
 	ret
 
 	.section .entry, "ax", %progbits

firmware/fw_payload.elf.ldS

@@ -14,7 +14,7 @@ SECTIONS
 {
 	#include "fw_base.ldS"
 
-#ifdef FW_PAYLOAD_OFFSET
+#if defined(FW_PAYLOAD_OFFSET) && !defined(FW_PAYLOAD_NOPAD)
 	. = FW_TEXT_START + FW_PAYLOAD_OFFSET;
 #else
 	. = ALIGN(FW_PAYLOAD_ALIGN);

firmware/fw_reloc_payload.S

@@ -0,0 +1,63 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021
+ * Authors: Tekkaman Ninja <tekkamanninja@163.com>
+ *
+ * t0 --> payload text base addr
+ * t1 --> payload end addr in fw_payload.bin
+ * t2 --> payload start addr in fw_payload.bin
+ * t3 --> payload text end addr (ti - t2 + t0)
+ * t4 --> _relocate_payload_done
+ *             t2          t1         t0            t3
+ * +-----------+-----------+----------+-------------+-------+
+ * |   fw_base + fw_payload| -------> |*fw_payload* |       |
+ * +-----------+-----------+----------+-------------+-------+
+ *
+ */
+
+_relocate_payload:
+	li	t0, (FW_TEXT_START + FW_PAYLOAD_OFFSET)
+	lla	t1, _pl_end
+	REG_L	t1, 0(t1)
+	lla	t2, _pl_start
+	REG_L	t2, 0(t2)
+
+	sub	t3, t1, t2
+	add	t3, t3, t0
+
+	beq	t0, t2, _relocate_payload_done
+
+	lla	t4, _relocate_payload_done
+
+	lla	t5, _load_start
+	REG_L	t5, 0(t5)
+	sub	t4, t4, t5
+
+	lla	t5, _link_start
+	REG_L	t5, 0(t5)
+	add	t4, t4, t5
+
+	blt	t2, t0, _relocate_payload_copy_to_upper_loop
+
+_relocate_payload_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	t2, t1, _relocate_payload_copy_to_lower_loop
+	jr	t4
+
+_relocate_payload_copy_to_upper_loop:
+	add	t3, t3, -__SIZEOF_POINTER__
+	add	t1, t1, -__SIZEOF_POINTER__
+	REG_L	t0, 0(t1)
+	REG_S	t0, 0(t3)
+	blt	t2, t1, _relocate_payload_copy_to_upper_loop
+	jr	t4
+
+	.align 3
+_pl_end:
+	RISCV_PTR	_payload_end
+_pl_start:
+	RISCV_PTR	_payload_start

firmware/objects.mk

@@ -59,6 +59,10 @@ ifdef FW_PAYLOAD_FDT_ADDR
 firmware-genflags-$(FW_PAYLOAD) += -DFW_PAYLOAD_FDT_ADDR=$(FW_PAYLOAD_FDT_ADDR)
 endif
 
+ifdef FW_PAYLOAD_NOPAD
+firmware-genflags-$(FW_PAYLOAD) += -DFW_PAYLOAD_NOPAD=$(FW_PAYLOAD_NOPAD)
+endif
+
 ifdef FW_OPTIONS
 firmware-genflags-y += -DFW_OPTIONS=$(FW_OPTIONS)
 endif

platform/starfive/vic7100/config.mk

@@ -42,3 +42,5 @@ FW_PAYLOAD=y
 FW_PAYLOAD_FDT_ADDR=0x88000000
 
 FW_PAYLOAD_ALIGN=0x1000
+
+FW_PAYLOAD_NOPAD=y