Add more complete fw_ram test; let testfw have stack in RAM

Signed-off-by: Daniel Lublin <daniel@lublin.se>

hw/application_fpga/Makefile

@@ -87,7 +87,7 @@ FIRMWARE_OBJS = \
 
 TESTFW_OBJS = \
 	$(P)/fw/testfw/main.o \
-	$(P)/fw/tk1/start.o \
+	$(P)/fw/testfw/start.o \
 	$(P)/fw/tk1/proto.o \
 	$(P)/fw/tk1/lib.o \
 	$(P)/fw/tk1/blake2s/blake2s.o
@@ -103,8 +103,10 @@ all: application_fpga.bin
 # incorrect BRAM_FW_SIZE
 # -------------------------------------------------------------------
 %_size_mismatch: %.elf phony_explicit
-	@test $$($(SIZE) $< | awk 'NR==2{print $$4}') -le $$(( 32 / 8 * $(BRAM_FW_SIZE) )) || \
+	@test $$($(SIZE) $< | awk 'NR==2{print $$4}') -le $$(( 32 / 8 * $(BRAM_FW_SIZE) )) \
-	(echo "The 'BRAM_FW_SIZE' variable needs to be increased" && false)
+	|| { printf "The 'BRAM_FW_SIZE' variable needs to be increased\n"; \
+	[[ $< =~ testfw ]] && printf "Note that testfw fits if built with -Os\n"; \
+	false; }
 
 # can't make implicit rule .PHONY
 phony_explicit:

hw/application_fpga/fw/testfw/main.c

@@ -105,6 +105,42 @@ uint32_t wait_timer_tick(uint32_t last_timer)
 	}
 }
 
+void zero_fwram()
+{
+	for (int i = 0; i < TK1_MMIO_FW_RAM_SIZE; i++) {
+		fw_ram[i] = 0x00;
+	}
+}
+
+int check_fwram_zero_except(unsigned int offset, uint8_t expected_val)
+{
+	int failed = 0;
+	for (unsigned int i = 0; i < TK1_MMIO_FW_RAM_SIZE; i++) {
+		uint32_t addr = TK1_MMIO_FW_RAM_BASE + i;
+		uint8_t *p = (uint8_t *)addr;
+		uint8_t val = *(volatile uint8_t *)p;
+		int failed_now = 0;
+		if (i == offset) {
+			if (val != expected_val) {
+				failed_now = 1;
+				puts("  wrong value at: ");
+			}
+		} else {
+			if (val != 0) {
+				failed_now = 1;
+				puts("  not zero at: ");
+			}
+		}
+		if (failed_now) {
+			failed = 1;
+			reverseword(&addr);
+			puthexn((uint8_t *)&addr, 4);
+			puts("\r\n");
+		}
+	}
+	return failed;
+}
+
 int main()
 {
 	// Function pointer to blake2s()
@@ -171,12 +207,14 @@ int main()
 		anyfailed = 1;
 	}
 
-	// Test FW-RAM.
+	// Test FW_RAM.
-	*fw_ram = 0x12;
+	puts("Testing FW_RAM (takes 15s on hw)...\r\n");
-	if (*fw_ram != 0x12) {
+	for (unsigned int i = 0; i < TK1_MMIO_FW_RAM_SIZE; i++) {
-		puts("FAIL: Can't write and read FW RAM in fw mode\r\n");
+		zero_fwram();
-		anyfailed = 1;
+		*(volatile uint8_t *)(TK1_MMIO_FW_RAM_BASE + i) = 0x42;
+		anyfailed = check_fwram_zero_except(i, 0x42);
 	}
+	puts("\r\n");
 
 	uint32_t sw = *switch_app;
 	if (sw != 0) {
@@ -190,10 +228,6 @@ int main()
 	// Turn on application mode.
 	// -------------------------
 
-	// Set up another stack because fw_ram is not available
-	// anymore in app_mode.
-	asm volatile("li sp, 0x40006ff0");
-
 	*switch_app = 1;
 
 	sw = *switch_app;
@@ -228,7 +262,7 @@ int main()
 		anyfailed = 1;
 	}
 
-	// Test FW-RAM.
+	// Test FW_RAM.
 	*fw_ram = 0x21;
 	if (*fw_ram == 0x21) {
 		puts("FAIL: Write and read FW RAM in app-mode\r\n");

hw/application_fpga/fw/testfw/start.S

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2022, 2023 - Tillitis AB
+ * SPDX-License-Identifier: GPL-2.0-only
+*/
+
+	.section ".text.init"
+	.globl _start
+_start:
+	li x1, 0
+	li x2, 0
+	li x3, 0
+	li x4, 0
+	li x5, 0
+	li x6, 0
+	li x7, 0
+	li x8, 0
+	li x9, 0
+	li x10,0
+	li x11,0
+	li x12,0
+	li x13,0
+	li x14,0
+	li x15,0
+	li x16,0
+	li x17,0
+	li x18,0
+	li x19,0
+	li x20,0
+	li x21,0
+	li x22,0
+	li x23,0
+	li x24,0
+	li x25,0
+	li x26,0
+	li x27,0
+	li x28,0
+	li x29,0
+	li x30,0
+	li x31,0
+
+	/* Clear all RAM */
+	li a0, 0x40000000 // TK1_RAM_BASE
+	li a1, 0x40020000 // TK1_RAM_BASE + TK1_RAM_SIZE
+clear:
+	sw zero, 0(a0)
+	addi a0, a0, 4
+	blt a0, a1, clear
+
+        /*
+         * For testfw we init stack at top of RAM
+         */
+        li sp, 0x40020000 // TK1_RAM_BASE + TK1_RAM_SIZE
+
+	call main
+
+loop:
+	j loop