From 92c5c2c5732c5358d7d1cbd34444aca65df08972 Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Wed, 17 Apr 2024 21:49:35 +0200
Subject: [PATCH] ram size configurable at run time

---
 bus.cpp      | 26 +++++++++++++++-----------
 bus.h        | 11 +++++++++++
 debugger.cpp | 19 +++++++++++++++++++
 3 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/bus.cpp b/bus.cpp
index bf962c0..604651a 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -14,18 +14,10 @@
 #include "tty.h"
 #include "utils.h"
 
-#if defined(ESP32) || defined(BUILD_FOR_RP2040)
 #if defined(ESP32)
 #include <esp_debug_helpers.h>
 #endif
 
-// ESP32 goes in a crash-loop when allocating 128kB
-// see also https://github.com/espressif/esp-idf/issues/1934
-constexpr int n_pages = 12;
-#else
-constexpr int n_pages = 31;  // 30=240kB (for EKBEEx.BIC)
-#endif
-
 constexpr const int di_ena_mask[4] = { 4, 2, 0, 1 };
 
 bus::bus()
@@ -49,6 +41,18 @@ bus::~bus()
 	delete m;
 }
 
+void bus::set_memory_size(const int n_pages)
+{
+	this->n_pages = n_pages;
+
+	uint32_t n_bytes = n_pages * 8192l;
+
+	delete m;
+	m = new memory(n_bytes);
+
+	DOLOG(info, false, "Memory is now %u kB in size", n_bytes / 1024);
+}
+
 void bus::reset()
 {
 	m->reset();
@@ -403,7 +407,7 @@ uint16_t bus::read(const uint16_t addr_in, const word_mode_t word_mode, const rm
 		}
 
 		// LO size register field must be all 1s, so subtract 1
-		constexpr uint32_t system_size = n_pages * 8192l / 64 - 1;
+		uint32_t system_size = n_pages * 8192l / 64 - 1;
 
 		if (a == ADDR_SYSSIZE + 2) {  // system size HI
 			uint16_t temp = system_size >> 16;
@@ -434,7 +438,7 @@ uint16_t bus::read(const uint16_t addr_in, const word_mode_t word_mode, const rm
 		return 0;
 	}
 
-	if (m_offset >= n_pages * 8192) {
+	if (m_offset >= uint32_t(n_pages * 8192)) {
 		if (peek_only) {
 			DOLOG(debug, false, "READ from %06o - out of range!", addr_in);
 			return 0;
@@ -1063,7 +1067,7 @@ write_rc_t bus::write(const uint16_t addr_in, const word_mode_t word_mode, uint1
 
 	DOLOG(debug, false, "WRITE to %06o/%07o %c %c: %06o", addr_in, m_offset, space == d_space ? 'D' : 'I', word_mode == wm_byte ? 'B' : 'W', value);
 
-	if (m_offset >= n_pages * 8192) {
+	if (m_offset >= uint32_t(n_pages * 8192)) {
 		c->trap(004);  // no such RAM
 		throw 1;
 	}
diff --git a/bus.h b/bus.h
index 8c577e1..fb3eac0 100644
--- a/bus.h
+++ b/bus.h
@@ -16,6 +16,13 @@
 #include "rp2040.h"
 #endif
 
+#if defined(ESP32) || defined(BUILD_FOR_RP2040)
+// ESP32 goes in a crash-loop when allocating 128kB
+// see also https://github.com/espressif/esp-idf/issues/1934
+#define DEFAULT_N_PAGES 12
+#else
+#define DEFAULT_N_PAGES 31
+#endif
 
 #define ADDR_MMR0 0177572
 #define ADDR_MMR1 0177574
@@ -97,6 +104,7 @@ private:
 	rl02    *rl02_ { nullptr };
 	tty     *tty_  { nullptr };
 
+	int      n_pages { DEFAULT_N_PAGES };
 	memory  *m     { nullptr };
 
 	// 8 pages, D/I, 3 modes and 1 invalid mode
@@ -132,6 +140,9 @@ public:
 	uint16_t get_console_switches() { return console_switches; }
 	void set_debug_mode() { console_switches |= 128; }
 
+	int  get_memory_size() const { return n_pages; }
+	void set_memory_size(const int n_pages);
+
 	void mmudebug(const uint16_t a);
 
 	uint16_t get_console_leds() { return console_leds; }
diff --git a/debugger.cpp b/debugger.cpp
index 2c2c7c9..cf2814c 100644
--- a/debugger.cpp
+++ b/debugger.cpp
@@ -987,6 +987,23 @@ void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const sto
 
 				continue;
 			}
+			else if (parts[0] == "ramsize") {
+				if (parts.size() == 2)
+					b->set_memory_size(std::stoi(parts.at(1)));
+				else {
+					int n_pages = b->get_memory_size();
+
+					cnsl->put_string_lf(format("Memory size: %u pages or %u kB (decimal)", n_pages, n_pages * 8192 / 1024));
+				}
+
+				continue;
+			}
+			else if (parts[0] == "bl" && parts.size() == 2) {
+				setBootLoader(b, parts.at(1) == "rk05" ? BL_RK05 : BL_RL02);
+				cnsl->put_string_lf("Bootloader set");
+
+				continue;
+			}
 			else if (parts[0] == "trl") {
 				if (parts.size() == 1)
 					t_rl.reset();
@@ -1066,6 +1083,8 @@ void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const sto
 					"toggle        - set switch (s=, 0...15 (decimal)) of the front panel to state (t=, 0 or 1)",
 					"cls           - clear screen",
 					"stats         - show run statistics",
+					"ramsize       - set ram size (page count (8 kB))",
+					"bl            - set bootload (rl02 or rk05)",
 #if defined(ESP32)
 					"cfgnet        - configure network (e.g. WiFi)",
 					"startnet      - start network",