From 832c3e5206173e3eff1f1ee8d0906274dabd3ae7 Mon Sep 17 00:00:00 2001
From: Sven Willner <sven.willner@gmail.com>
Date: Sat, 1 Aug 2020 17:25:50 +0200
Subject: [PATCH 1/4] Add load target and unify makefiles

---
 examples/riscv-blink/Makefile | 13 ++++++++++---
 sw/Makefile                   | 10 +++++++---
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/examples/riscv-blink/Makefile b/examples/riscv-blink/Makefile
index 7e2a4fb..b0b07c0 100644
--- a/examples/riscv-blink/Makefile
+++ b/examples/riscv-blink/Makefile
@@ -34,7 +34,9 @@ THIRD_PARTY := $(BASE_DIR)/third_party
 DBG_CFLAGS := -ggdb -g -DDEBUG -Wall
 DBG_LFLAGS := -ggdb -g -Wall
 CFLAGS     := $(ADD_CFLAGS) \
+			  -D__vexriscv__ -march=rv32i  -mabi=ilp32 \
 			  -Wall -Wextra \
+			  -flto \
 			  -ffunction-sections -fdata-sections -fno-common \
 			  -fomit-frame-pointer -Os \
 			  -march=rv32i \
@@ -42,6 +44,7 @@ CFLAGS     := $(ADD_CFLAGS) \
 CXXFLAGS   := $(CFLAGS) -std=c++11 -fno-rtti -fno-exceptions
 LFLAGS     := $(CFLAGS) $(ADD_LFLAGS) -L$(LD_DIR) \
 			  -nostartfiles \
+			  -nostdlib \
 			  -Wl,--gc-sections \
 			  -Wl,--no-warn-mismatch \
 			  -Wl,--script=$(LDSCRIPT) \
@@ -64,7 +67,7 @@ ALL        := all
 TARGET     := $(PACKAGE).elf
 CLEAN      := clean
 
-$(ALL): $(TARGET) $(PACKAGE).bin $(PACKAGE).ihex
+$(ALL): $(TARGET) $(PACKAGE).bin $(PACKAGE).ihex $(PACKAGE).dfu
 
 $(OBJECTS): | $(OBJ_DIR)
 
@@ -76,7 +79,7 @@ $(PACKAGE).bin: $(TARGET)
 	$(QUIET) echo "  OBJCOPY  $@"
 	$(QUIET) $(OBJCOPY) -O binary $(TARGET) $@
 
-$(PACKAGE).dfu: $(TARGET)
+$(PACKAGE).dfu: $(PACKAGE).bin
 	$(QUIET) echo "  DFU      $@"
 	$(QUIET) $(COPY) $(PACKAGE).bin $@
 	$(QUIET) dfu-suffix -v 1209 -p 70b1 -a $@
@@ -106,7 +109,7 @@ $(OBJ_DIR)/%.o: %.S
 	$(QUIET) echo "  AS       $<	$(notdir $@)"
 	$(QUIET) $(CC) -x assembler-with-cpp -c $< $(CFLAGS) -o $@ -MMD
 
-.PHONY: clean
+.PHONY: clean load
 
 clean:
 	$(QUIET) echo "  RM      $(subst /,$(PATH_SEP),$(wildcard $(OBJ_DIR)/*.d))"
@@ -116,4 +119,8 @@ clean:
 	$(QUIET) echo "  RM      $(TARGET) $(PACKAGE).bin $(PACKAGE).symbol $(PACKAGE).ihex $(PACKAGE).dfu"
 	-$(QUIET) $(RM) $(TARGET) $(PACKAGE).bin $(PACKAGE).symbol $(PACKAGE).ihex $(PACKAGE).dfu
 
+load: $(PACKAGE).dfu
+	$(QUIET) dfu-util -D $<
+
 include $(wildcard $(OBJ_DIR)/*.d)
+
diff --git a/sw/Makefile b/sw/Makefile
index 7983f6d..28de782 100644
--- a/sw/Makefile
+++ b/sw/Makefile
@@ -76,7 +76,7 @@ ALL        := all
 TARGET     := $(PACKAGE).elf
 CLEAN      := clean
 
-$(ALL): $(TARGET) $(PACKAGE).bin $(PACKAGE).ihex
+$(ALL): $(TARGET) $(PACKAGE).bin $(PACKAGE).ihex $(PACKAGE).dfu
 
 $(OBJECTS): | $(OBJ_DIR)
 
@@ -88,7 +88,7 @@ $(PACKAGE).bin: $(TARGET)
 	$(QUIET) echo "  OBJCOPY  $@"
 	$(QUIET) $(OBJCOPY) -O binary $(TARGET) $@
 
-$(PACKAGE).dfu: $(TARGET)
+$(PACKAGE).dfu: $(PACKAGE).bin
 	$(QUIET) echo "  DFU      $@"
 	$(QUIET) $(COPY) $(PACKAGE).bin $@
 	$(QUIET) dfu-suffix -v 1209 -p 70b1 -a $@
@@ -118,7 +118,7 @@ $(OBJ_DIR)/%.o: %.S
 	$(QUIET) echo "  AS       $<	$(notdir $@)"
 	$(QUIET) $(CC) -x assembler-with-cpp -c $< $(CFLAGS) -o $@ -MMD
 
-.PHONY: clean
+.PHONY: clean load
 
 clean:
 	$(QUIET) echo "  RM      $(subst /,$(PATH_SEP),$(wildcard $(OBJ_DIR)/*.d))"
@@ -128,4 +128,8 @@ clean:
 	$(QUIET) echo "  RM      $(TARGET) $(PACKAGE).bin $(PACKAGE).symbol $(PACKAGE).ihex $(PACKAGE).dfu"
 	-$(QUIET) $(RM) $(TARGET) $(PACKAGE).bin $(PACKAGE).symbol $(PACKAGE).ihex $(PACKAGE).dfu
 
+load: $(PACKAGE).dfu
+	$(QUIET) dfu-util -D $<
+
 include $(wildcard $(OBJ_DIR)/*.d)
+

From 538a82dc9cdbca66247fb321a33ed56ee9fd324a Mon Sep 17 00:00:00 2001
From: Sven Willner <sven.willner@gmail.com>
Date: Sat, 1 Aug 2020 17:28:24 +0200
Subject: [PATCH 2/4] Add options for ram boot compilation (LOAD_RAM_ADDR and
 LOAD_BOOT_CONFIG)

---
 examples/riscv-blink/Makefile            | 17 +++++++++++++++--
 examples/riscv-blink/ld/linker.ld        |  2 --
 examples/riscv-blink/ld/regions_ram.ld   |  5 +++++
 examples/riscv-blink/src/crt0-vexriscv.S |  8 +++++++-
 sw/Makefile                              | 15 ++++++++++++++-
 sw/ld/linker.ld                          |  2 --
 sw/ld/regions_ram.ld                     |  5 +++++
 sw/third_party/libbase/crt0-vexriscv.S   | 10 ++++++++++
 8 files changed, 56 insertions(+), 8 deletions(-)
 create mode 100644 examples/riscv-blink/ld/regions_ram.ld
 create mode 100644 sw/ld/regions_ram.ld

diff --git a/examples/riscv-blink/Makefile b/examples/riscv-blink/Makefile
index b0b07c0..961b365 100644
--- a/examples/riscv-blink/Makefile
+++ b/examples/riscv-blink/Makefile
@@ -26,9 +26,21 @@ LD_DIR     := $(BASE_DIR)/ld
 LDSCRIPT   := $(BASE_DIR)/ld/linker.ld
 ADD_CFLAGS := -I$(BASE_DIR)/include -D__vexriscv__ -march=rv32i  -mabi=ilp32
 ADD_LFLAGS := 
-PACKAGE    := example
+PACKAGE    := riscv-blink
 
-LDSCRIPTS  := $(LDSCRIPT) $(LD_DIR)/output_format.ld $(LD_DIR)/regions.ld
+ifdef LOAD_RAM_ADDR
+LDREGIONS  := $(LD_DIR)/regions_ram.ld
+ADD_CFLAGS += -DLOAD_RAM_ADDR=$(LOAD_RAM_ADDR)
+ADD_LFLAGS += -Wl,--defsym=LOAD_RAM_ADDR=$(LOAD_RAM_ADDR)
+else
+LDREGIONS  := $(LD_DIR)/regions.ld
+endif
+
+ifdef LOAD_BOOT_CONFIG
+ADD_CFLAGS += -DLOAD_BOOT_CONFIG=$(LOAD_BOOT_CONFIG)
+endif
+
+LDSCRIPTS  := $(LDSCRIPT) $(LDREGIONS) $(LD_DIR)/output_format.ld
 SRC_DIR    := $(BASE_DIR)/src
 THIRD_PARTY := $(BASE_DIR)/third_party
 DBG_CFLAGS := -ggdb -g -DDEBUG -Wall
@@ -47,6 +59,7 @@ LFLAGS     := $(CFLAGS) $(ADD_LFLAGS) -L$(LD_DIR) \
 			  -nostdlib \
 			  -Wl,--gc-sections \
 			  -Wl,--no-warn-mismatch \
+			  -Wl,--script=$(LDREGIONS) \
 			  -Wl,--script=$(LDSCRIPT) \
 			  -Wl,--build-id=none
 
diff --git a/examples/riscv-blink/ld/linker.ld b/examples/riscv-blink/ld/linker.ld
index 5796f16..aa2c483 100644
--- a/examples/riscv-blink/ld/linker.ld
+++ b/examples/riscv-blink/ld/linker.ld
@@ -3,8 +3,6 @@ ENTRY(_start)
 
 __DYNAMIC = 0;
 
-INCLUDE regions.ld
-
 SECTIONS
 {
 	.text :
diff --git a/examples/riscv-blink/ld/regions_ram.ld b/examples/riscv-blink/ld/regions_ram.ld
new file mode 100644
index 0000000..3c7c9f1
--- /dev/null
+++ b/examples/riscv-blink/ld/regions_ram.ld
@@ -0,0 +1,5 @@
+MEMORY {
+	ram : ORIGIN = LOAD_RAM_ADDR, LENGTH = 0x00010000
+}
+REGION_ALIAS("rom", ram)
+REGION_ALIAS("sram", ram)
diff --git a/examples/riscv-blink/src/crt0-vexriscv.S b/examples/riscv-blink/src/crt0-vexriscv.S
index 631b6a2..144bafe 100644
--- a/examples/riscv-blink/src/crt0-vexriscv.S
+++ b/examples/riscv-blink/src/crt0-vexriscv.S
@@ -6,8 +6,14 @@
 
 _start:
   j crt_init
+#ifdef LOAD_RAM_ADDR
+  .word 0x17ab0f23
+  .word LOAD_RAM_ADDR
+#endif
+#ifdef LOAD_BOOT_CONFIG
   .word 0xb469075a
-  .word 0x00000020
+  .word LOAD_BOOT_CONFIG
+#endif
 
 .section .text
 .global  trap_entry
diff --git a/sw/Makefile b/sw/Makefile
index 28de782..2c9a840 100644
--- a/sw/Makefile
+++ b/sw/Makefile
@@ -37,7 +37,19 @@ ADD_LFLAGS :=
 PACKAGE    := foboot
 endif
 
-LDSCRIPTS  := $(LDSCRIPT) $(LD_DIR)/output_format.ld $(LD_DIR)/regions.ld
+ifdef LOAD_RAM_ADDR
+LDREGIONS  := $(LD_DIR)/regions_ram.ld
+ADD_CFLAGS += -DLOAD_RAM_ADDR=$(LOAD_RAM_ADDR)
+ADD_LFLAGS += -Wl,--defsym=LOAD_RAM_ADDR=$(LOAD_RAM_ADDR)
+else
+LDREGIONS  := $(LD_DIR)/regions.ld
+endif
+
+ifdef LOAD_BOOT_CONFIG
+ADD_CFLAGS += -DLOAD_BOOT_CONFIG=$(LOAD_BOOT_CONFIG)
+endif
+
+LDSCRIPTS  := $(LDSCRIPT) $(LDREGIONS) $(LD_DIR)/output_format.ld
 SRC_DIR    := $(BASE_DIR)/src
 THIRD_PARTY := $(BASE_DIR)/third_party
 DBG_CFLAGS := -ggdb3 -DDEBUG -Wall
@@ -56,6 +68,7 @@ LFLAGS     := $(CFLAGS) $(ADD_LFLAGS) -L$(LD_DIR) \
 			  -nostdlib \
 			  -Wl,--gc-sections \
 			  -Wl,--no-warn-mismatch \
+			  -Wl,--script=$(LDREGIONS) \
 			  -Wl,--script=$(LDSCRIPT) \
 			  -Wl,--build-id=none
 
diff --git a/sw/ld/linker.ld b/sw/ld/linker.ld
index 5796f16..aa2c483 100644
--- a/sw/ld/linker.ld
+++ b/sw/ld/linker.ld
@@ -3,8 +3,6 @@ ENTRY(_start)
 
 __DYNAMIC = 0;
 
-INCLUDE regions.ld
-
 SECTIONS
 {
 	.text :
diff --git a/sw/ld/regions_ram.ld b/sw/ld/regions_ram.ld
new file mode 100644
index 0000000..3c7c9f1
--- /dev/null
+++ b/sw/ld/regions_ram.ld
@@ -0,0 +1,5 @@
+MEMORY {
+	ram : ORIGIN = LOAD_RAM_ADDR, LENGTH = 0x00010000
+}
+REGION_ALIAS("rom", ram)
+REGION_ALIAS("sram", ram)
diff --git a/sw/third_party/libbase/crt0-vexriscv.S b/sw/third_party/libbase/crt0-vexriscv.S
index 931d50a..6b48f5d 100644
--- a/sw/third_party/libbase/crt0-vexriscv.S
+++ b/sw/third_party/libbase/crt0-vexriscv.S
@@ -7,10 +7,20 @@
 _start:
   j crt_init
   nop
+#ifdef LOAD_RAM_ADDR
+  .word 0x17ab0f23
+  .word LOAD_RAM_ADDR
+#else
   nop
   nop
+#endif
+#ifdef LOAD_BOOT_CONFIG
+  .word 0xb469075a
+  .word LOAD_BOOT_CONFIG
+#else
   nop
   nop
+#endif
   nop
   nop
 

From 0bd7791aad829ce7cb9ce7226b1c7077554f67fc Mon Sep 17 00:00:00 2001
From: Sven Willner <sven.willner@gmail.com>
Date: Sat, 1 Aug 2020 17:38:23 +0200
Subject: [PATCH 3/4] Add documentation for ram boot and boot config make
 options

---
 doc/BOOT-SEQUENCE.md | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/doc/BOOT-SEQUENCE.md b/doc/BOOT-SEQUENCE.md
index 654b74c..bdbf3ce 100644
--- a/doc/BOOT-SEQUENCE.md
+++ b/doc/BOOT-SEQUENCE.md
@@ -14,7 +14,7 @@ At start, **FBU** is loaded by the hardware.  **FBU** will look for a special *F
 
 ## Boot Flags
 
-A series of *Boot Fags* determine how **FBU** and **FBM** hand over execution to the subsequent program.
+A series of *Boot Flags* determine hows **FBU** and **FBM** hand over execution to the subsequent program.
 
 *Boot Flags* are indicated by the magic number `0xb469075a`, followed by a
 32-bit field, in the first 128 bytes of the binary.
@@ -28,6 +28,8 @@ struct {
 }
 ```
 
+These can be provided when making the program (when using a Makefile as in `examples/riscv-blink`), e.g. `make LOAD_BOOT_CONFIG=0x00000020`.
+
 | Bit Flag | Short Name   | Description                                      |
 | -------- | ------------ | ------------------------------------------------ |
 | 00000001 | QPI_EN       | Enable QPI mode on the SPI flash                 |
@@ -45,10 +47,12 @@ If the DFU bootloader encounters the magic number `0x17ab0f23` within the first
 
 Note that the value following the magic number indicates the offset where the program will be loaded to.  This should be somewhere in RAM.  `0x10001000` is a good value, and is guaranteed to not interfere with Foboot itself.
 
+When using a Makefile as in `examples/riscv-blink` you can provide the offset as in `make LOAD_RAM_ADDR=0x10001000`. This makes sure that the linker links the binary as one block.
+
 ## Magic Numbers
 
 | Value        | Description                                 |
 | ------------ | ------------------------------------------- |
 | `0xb469075a` | Denotes the start of *boot flags* bitfield  |
 | `0x17ab0f23` | Loads the program into RAM instead of flash |
-| `0x032bd37d` | Indicates a valid **FBM** image             |
\ No newline at end of file
+| `0x032bd37d` | Indicates a valid **FBM** image             |

From 714814b7350fe01668e2c7cfd84a5cb41a4ddb42 Mon Sep 17 00:00:00 2001
From: Sven Willner <sven.willner@gmail.com>
Date: Sat, 1 Aug 2020 19:35:00 +0200
Subject: [PATCH 4/4] Fix spelling

---
 doc/BOOT-SEQUENCE.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/BOOT-SEQUENCE.md b/doc/BOOT-SEQUENCE.md
index bdbf3ce..29d12b1 100644
--- a/doc/BOOT-SEQUENCE.md
+++ b/doc/BOOT-SEQUENCE.md
@@ -14,7 +14,7 @@ At start, **FBU** is loaded by the hardware.  **FBU** will look for a special *F
 
 ## Boot Flags
 
-A series of *Boot Flags* determine hows **FBU** and **FBM** hand over execution to the subsequent program.
+A series of *Boot Flags* determines how **FBU** and **FBM** hand over execution to the subsequent program.
 
 *Boot Flags* are indicated by the magic number `0xb469075a`, followed by a
 32-bit field, in the first 128 bytes of the binary.