seminaries/binrep/qtrvsim_binrep/.gitignore

+*.o
+depend
+qtrvsim_binrep

seminaries/binrep/qtrvsim_binrep/Makefile

+ARCH=riscv64-unknown-elf
+#ARCH=riscv64-linux-gnu
+
+SOURCES = crt0local.S qtrvsim_binrep.c
+TARGET_EXE = qtrvsim_binrep
+
+CC=$(ARCH)-gcc
+CXX=$(ARCH)-g++
+AS=$(ARCH)-as
+LD=$(ARCH)-ld
+OBJCOPY=$(ARCH)-objcopy
+
+ARCHFLAGS += -mabi=ilp32
+ARCHFLAGS += -march=rv32i
+ARCHFLAGS += -fno-lto
+
+CFLAGS  += -ggdb -Os -Wall
+CXXFLAGS+= -ggdb -Os -Wall
+AFLAGS  += -ggdb
+LDFLAGS += -ggdb
+LDFLAGS += -nostartfiles
+LDFLAGS += -nostdlib
+LDFLAGS += -static
+#LDFLAGS += -specs=/opt/musl/riscv64-linux-gnu/lib/musl-gcc.specs
+
+LOADLIBES += -lgcc
+
+CFLAGS  += $(ARCHFLAGS)
+CXXFLAGS+= $(ARCHFLAGS)
+AFLAGS  += $(ARCHFLAGS)
+LDFLAGS += $(ARCHFLAGS)
+
+OBJECTS += $(filter %.o,$(SOURCES:%.S=%.o))
+OBJECTS += $(filter %.o,$(SOURCES:%.c=%.o))
+OBJECTS += $(filter %.o,$(SOURCES:%.cpp=%.o))
+
+all : default
+
+.PHONY : default clean dep all
+
+%.o:%.S
+	$(CC) -D__ASSEMBLY__ $(AFLAGS) -c $< -o $@
+
+%.o:%.c
+	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
+
+%.o:%.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $<
+
+%.s:%.c
+	$(CC) $(CFLAGS) $(CPPFLAGS) -S $< -o $@
+
+default : $(TARGET_EXE)
+
+$(TARGET_EXE) : $(OBJECTS)
+	$(CC) $(LDFLAGS) $^ $(LOADLIBES) -o $@
+
+dep: depend
+
+depend: $(SOURCES) $(glob *.h)
+	echo '# autogenerated dependencies' > depend
+ifneq ($(filter %.S,$(SOURCES)),)
+	$(CC)  -D__ASSEMBLY__ $(AFLAGS) -w -E -M $(filter %.S,$(SOURCES)) \
+	  >> depend
+endif
+ifneq ($(filter %.c,$(SOURCES)),)
+	$(CC) $(CFLAGS) $(CPPFLAGS) -w -E -M $(filter %.c,$(SOURCES)) \
+	  >> depend
+endif
+ifneq ($(filter %.cpp,$(SOURCES)),)
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -w -E -M $(filter %.cpp,$(SOURCES)) \
+	  >> depend
+endif
+
+clean:
+	rm -f *.o *.a $(OBJECTS) $(TARGET_EXE) depend
+
+#mips-elf-objdump --source -M no-aliases,reg-names=numeric qtmips_binrep
+
+-include depend

seminaries/binrep/qtrvsim_binrep/crt0local.S

+/* minimal replacement of crt0.o which is else provided by C library */
+
+.globl main
+.globl _start
+.globl __start
+
+.option norelax
+
+.text
+
+__start:
+_start:
+	.option push
+	.option norelax
+	la gp, __global_pointer$
+	.option pop
+	la      sp, __stack_end
+	addi    a0, zero, 0
+	addi    a1, zero, 0
+	jal     main
+quit:
+	addi    a0, zero, 0
+	addi    a7, zero, 93  /* SYS_exit */
+	ecall
+
+loop:	ebreak
+        beq     zero, zero, loop
+
+.bss
+
+__stack_start:
+	.skip   4096
+__stack_end:
+
+.end _start

seminaries/binrep/qtrvsim_binrep/qtrvsim_binrep.c

+/*******************************************************************
+  Simple program to demostrate binary reprezentation
+  on QtMips emulator developed by Karel Koci and Pavel Pisa.
+
+  qrmips_binrep.c       - main and only file
+
+  (C) Copyright 2004 - 2019 by Pavel Pisa
+      e-mail:   pisa@cmp.felk.cvut.cz
+      homepage: http://cmp.felk.cvut.cz/~pisa
+      work:     http://www.pikron.com/
+      license:  any combination GPL, LGPL, MPL or BSD licenses
+
+ *******************************************************************/
+
+#define _POSIX_C_SOURCE 200112L
+
+//#include <stdint.h>
+typedef unsigned int uint32_t;
+
+/*
+ * Next macros provides location of knobs and LEDs peripherals
+ * implemented on QtMips simulator.
+ *
+ * More information can be found on page
+ *   https://github.com/ppisa/QtMips
+ */
+
+
+/*
+ * Base address of the region where simple serial port (UART)
+ * implementation is mapped in emulated MIPS address space
+ */
+#define SERIAL_PORT_BASE   0xffffc000
+/*
+ * Byte offset of the 32-bit transition status register
+ * of the serial port
+ */
+#define SERP_TX_ST_REG_o         0x08
+
+/*
+ * Mask of the bit which inform that peripheral is ready to accept
+ * next character to send. If it is zero, then peripheral is
+ * busy by sending of previous character.
+ */
+#define SERP_TX_ST_REG_READY_m    0x1
+/*
+ * Byte offset of the UART transmit register.
+ * When the 32-bit word is written the least-significant (LSB)
+ * eight bits are send to the terminal.
+ */
+#define SERP_TX_DATA_REG_o        0x0c
+
+/*
+ * Base address of the region where knobs and LEDs peripherals
+ * are mapped in the emulated MIPS physical memory address space.
+ */
+#define SPILED_REG_BASE      0xffffc100
+
+/* Valid address range for the region */
+#define SPILED_REG_SIZE      0x00000100
+
+/*
+ * Byte offset of the register which controls individual LEDs
+ * in the row of 32 yellow LEDs. When the corresponding bit
+ * is set (value 1) then the LED is lit.
+ */
+#define SPILED_REG_LED_LINE_o           0x004
+
+/*
+ * The register to control 8 bit RGB components of brightness
+ * of the first RGB LED
+ */
+#define SPILED_REG_LED_RGB1_o           0x010
+
+/*
+ * The register to control 8 bit RGB components of brightness
+ * of the second RGB LED
+ */
+#define SPILED_REG_LED_RGB2_o           0x014
+
+/*
+ * The register which combines direct write to RGB signals
+ * of the RGB LEDs, write to the keyboard scan register
+ * and control of the two additional individual LEDs.
+ * The direct write to RGB signals is orred with PWM
+ * signal generated according to the values in previous
+ * registers.
+ */
+#define SPILED_REG_LED_KBDWR_DIRECT_o   0x018
+
+/*
+ * Register providing access to unfiltered encoder channels
+ * and keyboard return signals.
+ */
+#define SPILED_REG_KBDRD_KNOBS_DIRECT_o 0x020
+
+/*
+ * The register representing knobs positions as three
+ * 8-bit values where each value is incremented
+ * and decremented by the knob relative turning.
+ */
+#define SPILED_REG_KNOBS_8BIT_o         0x024
+
+
+static inline void serp_write_reg(uint32_t base, uint32_t reg, uint32_t val)
+{
+  *(volatile uint32_t *)(base + reg) = val;
+}
+static inline uint32_t serp_read_reg(uint32_t base, uint32_t reg)
+{
+  return *(volatile uint32_t *)(base + reg);
+}
+
+/*
+ * Send single byte by UART port to a terminal, wait for ready
+ * to send first.
+ */
+void serp_tx_byte(int data)
+{
+  while (!(serp_read_reg(SERIAL_PORT_BASE, SERP_TX_ST_REG_o) &
+                SERP_TX_ST_REG_READY_m));
+  serp_write_reg(SERIAL_PORT_BASE, SERP_TX_DATA_REG_o, data);
+}
+
+/*
+ * Write 32-bit hexadecimal number to the terminal.
+ */
+void serp_send_hex(unsigned int val)
+{
+  int i;
+  for (i = 8; i > 0; i--) {
+    char c = (val >> 28) & 0xf;
+    if (c < 10 )
+      c += '0';
+    else
+      c += 'A' - 10;
+    serp_tx_byte(c);
+    val <<= 4;
+  }
+}
+
+/*
+ * The main entry into example program
+ */
+int main(int argc, char *argv[])
+{
+  unsigned char *mem_base = (unsigned char *)SPILED_REG_BASE;
+
+  while (1) {
+     uint32_t rgb_knobs_value;
+     unsigned int uint_val;
+
+     /*
+      * Access register holding 8 bit relative knobs position
+      * The type "(volatile uint32_t*)" casts address obtained
+      * as a sum of base address and register offset to the
+      * pointer type which target in memory type is 32-bit unsigned
+      * integer. The "volatile" keyword ensures that compiler
+      * cannot reuse previously read value of the location.
+      */
+     rgb_knobs_value = *(volatile uint32_t*)(mem_base + SPILED_REG_KNOBS_8BIT_o);
+
+     /* Store the read value to the register controlling individual LEDs */
+     *(volatile uint32_t*)(mem_base + SPILED_REG_LED_LINE_o) = rgb_knobs_value;
+
+     /*
+      * Store RGB knobs values to the corersponding components controlling
+      * a color/brightness of the RGB LEDs
+      */
+     *(volatile uint32_t*)(mem_base + SPILED_REG_LED_RGB1_o) = rgb_knobs_value;
+
+     *(volatile uint32_t*)(mem_base + SPILED_REG_LED_RGB2_o) = ~rgb_knobs_value;
+
+     /* Assign value read from knobs to the basic signed and unsigned types */
+     uint_val = rgb_knobs_value;
+
+     /* Print values */
+     serp_send_hex(uint_val);
+     serp_tx_byte('\n');
+  }
+
+  return 0;
+}

seminaries/hello-apo/.gitignore

+*.o
+*.dump
+*-native
+*-x86
+*-riscv
+*-riscv64
+*-mips
+*-arm
+*-aarch64

seminaries/hello-apo/Makefile

+# Makefile to buidl example for different ISA targets
+# Select architecture by ARCH parameter
+#   native, x86, riscv, riscv64, mips, arm, aarch64
+
+# Specify source files of the program
+SOURCES = hello-apo.c
+
+# Specify base name of the executable - architecture
+TARGET_BASE = hello-apo
+
+# The actual target filename is unique for each architecture
+TARGET_EXE = $(TARGET_BASE)-$(ARCH)
+
+all: default
+
+.PHONY : all default build run dump clean
+
+ARCH_SUPPORTED = native x86 riscv riscv64 mips arm aarch64
+
+ifneq ($(MAKECMDGOALS),clean)
+ifeq ($(filter $(ARCH_SUPPORTED),$(ARCH)),)
+  $(error ARCH parameter has to be set accepted: x86, riscv, riscv64, mips and arm)
+endif
+endif
+
+# setting specific for riscv build for native build
+SOURCES-native +=
+LOADLIBES-native +=
+CC-native = gcc
+OBJDUMP-native = objdump
+ARCHFLAGS-native += -ggdb
+RUN-native =
+
+# setting specific for riscv build for native build
+SOURCES-x86 +=
+LOADLIBES-x86 +=
+CC-x86 = x86_64-linux-gnu-gcc
+OBJDUMP-x86 = x86_64-linux-gnu-objdump
+ARCHFLAGS-native += -static  -ggdb
+RUN-x86 = qemu-x86_64-static
+
+# setting specific for riscv build for QtRvSim simulator and or RISC-V Linux 32-bit run
+SOURCES-riscv += sys-qtrvsim/qtrvsim_sys_stub.c sys-qtrvsim/crt0local.S
+LOADLIBES-riscv += -lc -lgcc
+CC-riscv = riscv64-unknown-elf-gcc
+OBJDUMP-riscv = riscv64-unknown-elf-objdump
+ARCHFLAGS-riscv += -mabi=ilp32 -march=rv32im -fno-lto -nostartfiles -nostdlib -static -ggdb
+RUN-riscv = qemu-riscv32-static
+
+# setting specific for riscv64 build for QtRvSim simulator and or RISC-V Linux 64-bit run
+SOURCES-riscv64 += sys-qtrvsim/qtrvsim_sys_stub.c sys-qtrvsim/crt0local.S
+LOADLIBES-riscv64 += -lc -lgcc
+CC-riscv64 = riscv64-unknown-elf-gcc
+OBJDUMP-riscv64 = riscv64-unknown-elf-objdump
+ARCHFLAGS-riscv64 += -mabi=lp64 -march=rv64imac -fno-lto -nostartfiles -nostdlib -static -ggdb
+RUN-riscv64 = qemu-riscv64-static
+
+# setting specific for riscv64 build for QtMips simulator and or MIPS Linux run
+SOURCES-mips += sys-qtmips/qtmips_sys_stub.c sys-qtmips/crt0local.S
+LOADLIBES-mips += -lc -lgcc
+CC-mips = mips-elf-gcc
+OBJDUMP-mips = mips-elf-objdump
+ARCHFLAGS-mips += -march=mips32 -fno-lto -nostartfiles -nostdlib -static -ggdb
+RUN-mips = qemu-mips-static
+
+# setting specific for ARM 32-bit build
+SOURCES-arm +=
+LOADLIBES-arm +=
+CC-arm = arm-linux-gnueabihf-gcc
+OBJDUMP-arm = arm-linux-gnueabihf-objdump
+ARCHFLAGS-arm += -static -ggdb
+RUN-arm = qemu-arm-static
+
+# setting specific for ARM 64-bit build
+SOURCES-aarch64 +=
+LOADLIBES-aarch64 +=
+CC-aarch64 = aarch64-linux-gnu-gcc
+OBJDUMP-aarch64 = aarch64-linux-gnu-objdump
+ARCHFLAGS-aarch64 += -static -ggdb
+RUN-aarch64 = qemu-aarch64-static
+
+define compile_one_src
+src := $(1)
+arch := $(2)
+obj := $$(basename $$(notdir $$(src)))-$$(arch).o
+$$(obj) : $$(src)
+	$$(CC-$$(arch)) $$(ARCHFLAGS-$$(arch)) -c $$< -o $$@
+OBJS-$$(arch) := $$(OBJS-$$(arch)) $$(obj)
+#$$(warning $$(src) $$(obj) $$(arch) $$(OBJS-$$(arch)))
+endef
+
+$(foreach srci, $(SOURCES) $(SOURCES-$(ARCH)),$(eval $(call compile_one_src, $(srci), $(ARCH))))
+
+$(TARGET_EXE) : $(OBJS-$(ARCH))
+	$(CC-$(ARCH)) -o $@ $^ $(ARCHFLAGS-$(ARCH)) $(LOADLIBES-$(ARCH))
+
+build : $(TARGET_EXE)
+
+run : $(TARGET_EXE)
+	$(RUN-$(ARCH)) ./$<
+
+dump: $(TARGET_EXE)
+	$(OBJDUMP-$(ARCH)) --source $< > $<.dump
+	cat $<.dump
+
+clean :
+	rm -f $(OBJS-$(ARCH)) $(foreach arch,$(ARCH_SUPPORTED),$(TARGET_BASE)-$(arch)) *.o *.dump
+
+default : build
\ No newline at end of file

seminaries/hello-apo/hello-apo.c

+/* Hello world example to demonstrate on multiple architectures */
+
+/*
+ * compile, run and examine for different instruction set architectures
+ * build by make command where ARCH is chisen as one of
+ *   native, x86, riscv, riscv64, mips, arm or aarch64
+ *   make ARCH=riscv
+ */
+
+#include <stdio.h>
+
+//int var_a = 40;
+//int var_b =  2;
+
+int main(int argc, char *argv[])
+{
+
+  /*
+   * modify program to compute and print answer
+   * of var_a + var_b
+   */
+  printf("Hello APO\n");
+
+  return 0;
+}

seminaries/hello-apo/sys-qtmips/crt0local.S

+/* minimal replacement of crt0.o which is else provided by C library */
+
+.globl main
+.globl _start
+.globl __start
+.globl _heap_stack_start
+.globl _heap_stack_end
+.set noat
+.set noreorder
+.ent _start
+
+.text
+
+__start:
+_start:
+#if defined(__PIC__) || defined(__pic__)
+	bal     next
+	nop
+next:
+	.set    noreorder
+	.cpload $31
+	.set    reorder
+#else
+	la      $gp, _gp
+#endif
+	la      $sp, _heap_stack_end
+	addi    $a0, $zero, 0
+	addi    $a1, $zero, 0
+	jal     main
+	nop
+quit:
+	addi    $a0, $zero, 0
+	addi    $v0, $zero, 4001  /* SYS_exit */
+
+	syscall
+
+loop:	break
+	beq     $zero, $zero, loop
+	nop
+
+.end _start
+
+.bss
+
+_heap_stack_start:
+	.skip  0x800000
+_heap_stack_end:

seminaries/hello-apo/sys-qtmips/qtmips_sys_stub.c

+/* Support files for GNU libc.  Files in the system namespace go here.
+   Files in the C namespace (ie those that do not start with an
+   underscore) go in .c.  */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/fcntl.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <time.h>
+#include <sys/time.h>
+#include <sys/times.h>
+#include <errno.h>
+#include <reent.h>
+#include "qtmips_unistd.h"
+
+#define UNUSED_PARAM(symbol) ((void)(symbol))
+
+/* Register name - works in collusion with the linker.  */
+register char * stack_ptr asm ("sp");
+
+
+int _read(int file, char *ptr, int len);
+int
+_read (int file,
+       char * ptr,
+       int len)
+{
+	register int __v0 asm("$v0") = __NR_read;
+	register int __a0 asm("$a0") = file;
+	register char * __a1 asm("$a1") = ptr;
+	register int __a2 asm("$a2") = len;
+	register int __a3 asm("$a3");
+	__asm__ volatile (
+	".set\tnoreorder\n\t"
+	"syscall\n\t"
+	".set reorder"
+	: "=r" (__v0), "=r" (__a3)
+	: "r" (__v0), "r" (__a0), "r" (__a1), "r"(__a2)
+	: );
+	return __a3? -1: __v0;
+}
+
+int _write(int file, const char *ptr, int len);
+int
+_write (int    file,
+	const char * ptr,
+	int    len)
+{
+	register int __v0 asm("$v0") = __NR_write;
+	register int __a0 asm("$a0") = file;
+	register const char * __a1 asm("$a1") = ptr;
+	register int __a2 asm("$a2") = len;
+	register int __a3 asm("$a3");
+	__asm__ volatile (
+	".set\tnoreorder\n\t"
+	"syscall\n\t"
+	".set reorder"
+	: "=r" (__v0), "=r" (__a3)
+	: "r" (__v0), "r" (__a0), "r" (__a1), "r"(__a2)
+	: );
+	return __a3? -1: __v0;
+}
+
+
+int
+_lseek (int file,
+	int pos,
+	int dir)
+{
+	UNUSED_PARAM(file);
+	UNUSED_PARAM(pos);
+	UNUSED_PARAM(dir);
+
+	return -1;
+}
+
+int _open(const char *path, int flags,	...);
+int
+_open (const char * path,
+       int          flags,
+       ...)
+{
+	register int __v0 asm("$v0") = __NR_open;
+	register const char * __a0 asm("$a0") = path;
+	register int __a1 asm("$a1") = flags;
+	register int __a2 asm("$a2") = 0;
+	register int __a3 asm("$a3");
+
+	if (flags & O_CREAT) {
+		va_list list;
+		va_start(list, flags);
+		__a2 = va_arg(list, int);
+		va_end(list);
+	}
+
+	__asm__ volatile (
+	".set\tnoreorder\n\t"
+	"syscall\n\t"
+	".set reorder"
+	: "=r" (__v0), "=r" (__a3)
+	: "r" (__v0), "r" (__a0), "r" (__a1), "r"(__a2)
+	: );
+	return __a3? -1: __v0;
+}
+
+int _close(int file);
+int
+_close (int file)
+{
+	register int __v0 asm("$v0") = __NR_close;
+	register int __a0 asm("$a0") = file;
+	register int __a3 asm("$a3");
+	__asm__ volatile (
+	".set\tnoreorder\n\t"
+	"syscall\n\t"
+	".set reorder"
+	: "=r" (__v0), "=r" (__a3)
+	: "r" (__v0), "r" (__a0)
+	: );
+	return __a3? -1: __v0;
+}
+
+void _exit(int n);
+void
+_exit (int n)
+{
+	register int __v0 asm("$v0") = __NR_exit;
+	register int __a0 asm("$a0") = n;
+
+	while(1) __asm__ volatile (
+	".set\tnoreorder\n\t"
+	"syscall\n\t"
+	".set reorder"
+	:
+	: "r" (__v0), "r" (__a0)
+	: "a3");
+}
+
+void abort(void);
+void abort(void)
+{
+	while(1) __asm__ volatile (
+	".set\tnoreorder\n\t"
+	"break\n\t"
+	".set reorder"
+	:
+	:
+	: );
+}
+
+int _kill(int n, int m);
+int
+_kill (int n, int m)
+{
+  UNUSED_PARAM(n);
+  UNUSED_PARAM(m);
+  return -1;
+}
+
+int _getpid(void);
+int
+_getpid (void)
+{
+  return 1;
+}
+
+
+void *_sbrk(ptrdiff_t incr);
+void *
+_sbrk (ptrdiff_t incr)
+{
+  extern char    _heap_stack_start;
+  static char   *heap_end;
+  char *        prev_heap_end;
+
+  incr=(incr+3) & ~3;
+
+  if (heap_end == NULL)
+    heap_end = & _heap_stack_start;
+
+  prev_heap_end = heap_end;
+
+  if ((heap_end + incr > stack_ptr) && (&_heap_stack_start < stack_ptr))
+    {
+      /* Some of the libstdc++-v3 tests rely upon detecting
+	 out of memory errors, so do not abort here.  */
+#if 1
+      extern void abort (void);
+
+      _write (1, "_sbrk: Heap and stack collision\n", 32);
+
+      abort ();
+#else
+      errno = ENOMEM;
+      return (caddr_t) -1;
+#endif
+    }
+
+  heap_end += incr;
+
+  return /*(caddr_t)*/ prev_heap_end;
+}
+
+int _fstat(int file, struct stat *st);
+int
+_fstat (int file, struct stat * st)
+{
+  UNUSED_PARAM(file);
+  UNUSED_PARAM(st);
+  return -1;
+}
+
+int _stat (const char *fname, struct stat *st);
+int _stat (const char *fname, struct stat *st)
+{
+  UNUSED_PARAM(fname);
+  UNUSED_PARAM(st);
+  return -1;
+}
+
+int _link(const char *path1, const char *path2);
+int
+_link (const char *path1,
+       const char *path2)
+{
+  UNUSED_PARAM(path1);
+  UNUSED_PARAM(path2);
+  return -1;
+}
+
+int _unlink(const char *path);
+int
+_unlink (const char *path)
+{
+  UNUSED_PARAM(path);
+  return -1;
+}
+
+void _raise(void);
+void
+_raise (void)
+{
+  return;
+}
+
+int _gettimeofday(struct timeval *tp, struct timezone *tzp);
+int
+_gettimeofday (struct timeval *tp,
+	       struct timezone *tzp)
+{
+
+  if(tp)
+    {
+      tp->tv_sec = 0;
+      tp->tv_usec = 0;
+    }
+  /* Return fixed data for the timezone.  */
+  if (tzp)
+    {
+      tzp->tz_minuteswest = 0;
+      tzp->tz_dsttime = 0;
+    }
+
+  return 0;
+}
+
+/* Return a clock that ticks at 100Hz.  */
+clock_t _times(struct tms *tp);
+clock_t
+_times (struct tms * tp)
+{
+  clock_t timeval = 0;
+
+  if (tp)
+    {
+      tp->tms_utime  = timeval;	/* user time */
+      tp->tms_stime  = 0;	/* system time */
+      tp->tms_cutime = 0;	/* user time, children */
+      tp->tms_cstime = 0;	/* system time, children */
+    }
+
+  return timeval;
+};
+
+
+int isatty(int fd);
+int
+isatty (int fd)
+{
+  UNUSED_PARAM(fd);
+  return 1;
+}
+
+int _system(const char *s);
+int
+_system (const char *s)
+{
+  UNUSED_PARAM(s);
+  return -1;
+}
+
+int _rename(const char *oldpath, const char *newpath);
+int
+_rename (const char * oldpath, const char * newpath)
+{
+  UNUSED_PARAM(oldpath);
+  UNUSED_PARAM(newpath);
+  return -1;
+}
+
+/* extern (.*) ([^ ]*) _PARAMS \(\(struct _reent \*(,*)(.*)\)\); */
+/* \1 \2 (struct _reent *\3\4) { return \2(\4);} */
+
+struct _reent;
+
+int _close_r(struct _reent *reent, int file)
+{ UNUSED_PARAM(reent); return _close(file);}
+/*
+  int _fcntl_r(struct _reent *, int, int, int)
+  { return _fcntl( int, int, int);}
+*/
+int _fstat_r(struct _reent *reent, int file, struct stat *st);
+int _fstat_r(struct _reent *reent, int file, struct stat *st)
+{ UNUSED_PARAM(reent); return _fstat(file, st);}
+
+int _getpid_r(struct _reent *reent);
+int _getpid_r(struct _reent *reent)
+{ UNUSED_PARAM(reent); return _getpid();}
+
+int _kill_r(struct _reent *reent, int n, int m);
+int _kill_r(struct _reent *reent, int n, int m)
+{ UNUSED_PARAM(reent); return _kill(n, m);}
+
+int _link_r(struct _reent *reent, const char *path1, const char *path2);
+int _link_r(struct _reent *reent, const char *path1, const char *path2)
+{ UNUSED_PARAM(reent); return _link(path1, path2);}
+
+_off_t _lseek_r(struct _reent *reent, int file, _off_t pos, int dir);
+_off_t _lseek_r(struct _reent *reent, int file, _off_t pos, int dir)
+{ UNUSED_PARAM(reent); return _lseek(file, pos, dir);}
+
+int _open_r(struct _reent *reent, const char *path, int flags, int opts);
+int _open_r(struct _reent *reent, const char *path, int flags, int opts)
+{ UNUSED_PARAM(reent); return _open(path, flags, opts);}
+
+_ssize_t _read_r(struct _reent *reent, int file, void *ptr, size_t len);
+_ssize_t _read_r(struct _reent *reent, int file, void *ptr, size_t len)
+{ UNUSED_PARAM(reent); return _read(file, ptr, len);}
+
+void *_sbrk_r(struct _reent *reent, ptrdiff_t incr);
+void *_sbrk_r(struct _reent *reent, ptrdiff_t incr)
+{ UNUSED_PARAM(reent); return _sbrk(incr);}
+
+int _stat_r(struct _reent *reent, const char *path, struct stat *st);
+int _stat_r(struct _reent *reent, const char *path, struct stat *st)
+{ UNUSED_PARAM(reent); return _stat(path, st);}
+
+int _unlink_r(struct _reent *reent, const char *path);
+int _unlink_r(struct _reent *reent, const char *path)
+{ UNUSED_PARAM(reent); return _unlink(path);}
+
+_ssize_t _write_r(struct _reent *reent, int file, const void *ptr, size_t len);
+_ssize_t _write_r(struct _reent *reent, int file, const void *ptr, size_t len)
+{ UNUSED_PARAM(reent); return _write(file, ptr, len);}
+
+/* FIXME: TDK added dummy functions. Need to implement. */
+int _isatty(int fd);
+int _isatty(int fd)
+{
+  UNUSED_PARAM(fd);
+  return -1;
+}
+
+int _swistat(int fd, struct stat *st);
+int _swistat(int fd, struct stat *st)
+{
+  UNUSED_PARAM(fd);
+  UNUSED_PARAM(st);
+  return -1;
+}
+
+/* Return a clock that ticks at 100Hz.  */
+clock_t _clock(void);
+clock_t _clock(void)
+{
+  clock_t timeval=0;
+  return timeval;
+}
+
+int _swiclose(int fh);
+int _swiclose(int fh)
+{
+  UNUSED_PARAM(fh);
+  return -1;
+}
+
+int _swiopen(const char *path, int flags);
+int _swiopen(const char *path, int flags)
+{
+  UNUSED_PARAM(path);
+  UNUSED_PARAM(flags);
+  return -1;
+}
+
+int _swiwrite(int fh, char *ptr, int len);
+int _swiwrite(int fh, char *ptr, int len)
+{
+  UNUSED_PARAM(fh);
+  UNUSED_PARAM(ptr);
+  UNUSED_PARAM(len);
+  return -1;
+}
+
+int _swilseek(int fd, int ptr, int dir);
+int _swilseek(int fd, int ptr, int dir)
+{
+  UNUSED_PARAM(fd);
+  UNUSED_PARAM(ptr);
+  UNUSED_PARAM(dir);
+  return -1;
+}
+
+int _swiread(int fh, char *ptr,	int len);
+int _swiread(int fh, char *ptr,	int len)
+{
+  UNUSED_PARAM(fh);
+  UNUSED_PARAM(ptr);
+  UNUSED_PARAM(len);
+  return -1;
+}
+
+void initialise_monitor_handles(void);
+void initialise_monitor_handles(void)
+{
+}

seminaries/hello-apo/sys-qtmips/qtmips_unistd.h

+// ******************************************************************
+//  QtMips emulator https://github.com/cvut/QtMips support filees
+//
+//  qtmips_unistd.h  - definition of the QtMips syscall numbers
+//
+//  (C) Copyright 2019 - 2020 by Pavel Pisa
+//      e-mail:   pisa@cmp.felk.cvut.cz
+//      homepage: http://cmp.felk.cvut.cz/~pisa
+//      license:  any combination of GPL, LGPL, MPL or BSD licenses
+//
+// ******************************************************************
+
+#ifndef QTMIPS_UNISTD_H
+#define QTMIPS_UNISTD_H
+
+// Linux kernel compatible system calls subset
+
+#define __NR_exit     4001	// void exit(int status)
+#define __NR_read     4003	// ssize_t read(int fd, void *buf, size_t count)
+#define __NR_write    4004	// ssize_t write(int fd, const void *buf, size_t count)
+#define __NR_close    4006	// int close(int fd)
+#define __NR_open     4005	// int open(const char *pathname, int flags, mode_t mode)
+#define __NR_brk      4045	// void * brk(void *addr)
+#define __NR_truncate 4092	// int ftruncate(int fd, off_t length)
+#define __NR_readv    4145	// ssize_t readv(int fd, const struct iovec *iov, int iovcnt)
+#define __NR_writev   4146	// ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
+#define __NR_set_thread_area 4283 // int set_thread_area(unsigned long addr)
+
+#endif /*QTMIPS_UNISTD_H*/

seminaries/hello-apo/sys-qtrvsim/crt0local.S

+/* minimal replacement of crt0.o which is else provided by C library */
+
+.globl main
+.globl _start
+.globl __start
+.globl _heap_stack_start
+.globl _heap_stack_end
+
+.option norelax
+
+.text
+
+__start:
+_start:
+	.option push
+	.option norelax
+	la gp, __global_pointer$
+	.option pop
+	la      sp, _heap_stack_end
+	addi    a0, zero, 0
+	addi    a1, zero, 0
+	jal     main
+quit:
+	addi    a0, zero, 0
+	addi    a7, zero, 93  /* SYS_exit */
+	ecall
+
+loop:	ebreak
+        beq     zero, zero, loop
+
+.bss
+
+_heap_stack_start:
+	.skip   16384
+_heap_stack_end:
+
+.end _start

seminaries/hello-apo/sys-qtrvsim/qtrvsim_sys_stub.c

+/* Support files for GNU libc.  Files in the system namespace go here.
+   Files in the C namespace (ie those that do not start with an
+   underscore) go in .c.  */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/fcntl.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <time.h>
+#include <sys/time.h>
+#include <sys/times.h>
+#include <errno.h>
+#include <reent.h>
+#include "qtrvsim_unistd.h"
+
+#define UNUSED_PARAM(symbol) ((void)(symbol))
+
+
+/* Open flags definition for Linux kernel copied from musl-libc */
+
+#define KERNEL_O_CREAT        0100
+#define KERNEL_O_EXCL         0200
+#define KERNEL_O_NOCTTY       0400
+#define KERNEL_O_TRUNC       01000
+#define KERNEL_O_APPEND      02000
+#define KERNEL_O_NONBLOCK    04000
+#define KERNEL_O_DSYNC      010000
+#define KERNEL_O_SYNC     04010000
+#define KERNEL_O_RSYNC    04010000
+#define KERNEL_O_DIRECTORY 0200000
+#define KERNEL_O_NOFOLLOW  0400000
+#define KERNEL_O_CLOEXEC  02000000
+
+#define KERNEL_O_PATH 010000000
+
+#define KERNEL_O_SYNC1 040000
+
+#define KERNEL_O_ACCMODE (03 | KERNEL_O_PATH)
+#define KERNEL_O_RDONLY 00
+#define KERNEL_O_WRONLY 01
+#define KERNEL_O_RDWR 02
+
+#define TARGET_AT_FDCWD -100
+
+/* Register name - works in collusion with the linker.  */
+register char * stack_ptr asm ("sp");
+
+
+int _read(int file, char *ptr, int len);
+int
+_read (int file,
+       char * ptr,
+       int len)
+{
+	register int __a7 asm("a7") = __NR_read;
+	register int __a0 asm("a0") = file;
+	register char * __a1 asm("a1") = ptr;
+	register int __a2 asm("a2") = len;
+	__asm__ volatile (
+	"ecall\n\t"
+	: "=r" (__a0)
+	: "r" (__a7), "r" (__a0), "r" (__a1), "r"(__a2)
+	: );
+	return __a0 < 0 ? -1: __a0;
+}
+
+int _write(int file, const char *ptr, int len);
+int
+_write (int    file,
+	const char * ptr,
+	int    len)
+{
+	register int __a7 asm("a7") = __NR_write;
+	register int __a0 asm("a0") = file;
+	register const char * __a1 asm("a1") = ptr;
+	register int __a2 asm("a2") = len;
+	__asm__ volatile (
+	"ecall\n\t"
+	: "=r" (__a0)
+	: "r" (__a7), "r" (__a0), "r" (__a1), "r"(__a2)
+	: );
+	return __a0 < 0 ? -1: __a0;
+}
+
+
+int
+_lseek (int file,
+	int pos,
+	int dir)
+{
+	UNUSED_PARAM(file);
+	UNUSED_PARAM(pos);
+	UNUSED_PARAM(dir);
+
+	return -1;
+}
+
+int _openat(int fd, const char *path, int flags,	...);
+int
+_openat (int fd, const char * path,
+       int          flags,
+       ...)
+{
+	register int __a7 asm("a7") = __NR_openat;
+	// use fd = -100 for normal open behaviour. Full openat not supported.
+	register int __a0 asm("a0") = fd;
+	register const char * __a1 asm("a1") = path;
+	register int __a2 asm("a2") = 0;
+	register int __a3 asm("a3");
+
+#ifdef O_CREAT
+	if (flags & O_CREAT)
+		__a2 |= KERNEL_O_CREAT;
+#endif
+#ifdef O_EXCL
+	if (flags & O_EXCL)
+		__a2 |= KERNEL_O_EXCL;
+#endif
+#ifdef O_NOCTTY
+	if (flags & O_NOCTTY)
+		__a2 |= KERNEL_O_NOCTTY;
+#endif
+#ifdef O_TRUNC
+	if (flags & O_TRUNC)
+		__a2 |= KERNEL_O_TRUNC;
+#endif
+#ifdef O_APPEND
+	if (flags & O_APPEND)
+		__a2 |= KERNEL_O_APPEND;
+#endif
+#ifdef O_NONBLOCK
+	if (flags & O_NONBLOCK)
+		__a2 |= KERNEL_O_NONBLOCK;
+#endif
+#ifdef O_DSYNC
+	if (flags & O_DSYNC)
+		__a2 |= KERNEL_O_DSYNC;
+#endif
+#ifdef O_SYNC
+	if (flags & O_SYNC)
+		__a2 |= KERNEL_O_SYNC;
+#endif
+#ifdef O_RSYNC
+	if (flags & O_RSYNC)
+		__a2 |= KERNEL_O_RSYNC;
+#endif
+#ifdef O_DIRECTORY
+	if (flags & O_DIRECTORY)
+		__a2 |= KERNEL_O_DIRECTORY;
+#endif
+#ifdef O_NOFOLLOW
+	if (flags & O_NOFOLLOW)
+		__a2 |= KERNEL_O_NOFOLLOW;
+#endif
+#ifdef O_CLOEXEC
+	if (flags & O_CLOEXEC)
+		__a2 |= KERNEL_O_CLOEXEC;
+#endif
+
+	if (flags & O_CREAT) {
+		va_list list;
+		va_start(list, flags);
+		__a3 = va_arg(list, int);
+		va_end(list);
+	}
+
+	__asm__ volatile (
+	"ecall\n\t"
+	: "=r" (__a0)
+	: "r" (__a7), "r" (__a0), "r" (__a1), "r"(__a2), "r"(__a3)
+	: );
+	return __a0 < 0 ? -1: __a0;
+}
+
+int _close(int file);
+int
+_close (int file)
+{
+	register int __a7 asm("a7") = __NR_close;
+	register int __a0 asm("a0") = file;
+	__asm__ volatile (
+	"ecall\n\t"
+	: "=r" (__a0)
+	: "r" (__a7), "r" (__a0)
+	: );
+	return __a0 < 0 ? -1: __a0;
+}
+
+void _exit(int n);
+void
+_exit (int n)
+{
+	register int __a7 asm("a7") = __NR_exit;
+	register int __a0 asm("a0") = n;
+
+	while(1) __asm__ volatile (
+	"ecall\n\t"
+	:
+	: "r" (__a7), "r" (__a0)
+	: );
+}
+
+void abort(void);
+void abort(void)
+{
+	while(1) __asm__ volatile (
+	"ebreak\n\t"
+	:
+	:
+	: );
+}
+
+int _kill(int n, int m);
+int
+_kill (int n, int m)
+{
+  UNUSED_PARAM(n);
+  UNUSED_PARAM(m);
+  return -1;
+}
+
+int _getpid(void);
+int
+_getpid (void)
+{
+  return 1;
+}
+
+
+void *_sbrk(ptrdiff_t incr);
+void *
+_sbrk (ptrdiff_t incr)
+{
+  extern char    _heap_stack_start;
+  static char   *heap_end;
+  char *        prev_heap_end;
+
+  incr=(incr+3) & ~3;
+
+  if (heap_end == NULL)
+    heap_end = & _heap_stack_start;
+
+  prev_heap_end = heap_end;
+
+  if ((heap_end + incr > stack_ptr) && (&_heap_stack_start < stack_ptr))
+    {
+      /* Some of the libstdc++-v3 tests rely upon detecting
+	 out of memory errors, so do not abort here.  */
+#if 1
+      extern void abort (void);
+
+      _write (1, "_sbrk: Heap and stack collision\n", 32);
+
+      abort ();
+#else
+      errno = ENOMEM;
+      return (caddr_t) -1;
+#endif
+    }
+
+  heap_end += incr;
+
+  return /*(caddr_t)*/ prev_heap_end;
+}
+
+int _fstat(int file, struct stat *st);
+int
+_fstat (int file, struct stat * st)
+{
+  UNUSED_PARAM(file);
+  UNUSED_PARAM(st);
+  return -1;
+}
+
+int _stat (const char *fname, struct stat *st);
+int _stat (const char *fname, struct stat *st)
+{
+  UNUSED_PARAM(fname);
+  UNUSED_PARAM(st);
+  return -1;
+}
+
+int _link(const char *path1, const char *path2);
+int
+_link (const char *path1,
+       const char *path2)
+{
+  UNUSED_PARAM(path1);
+  UNUSED_PARAM(path2);
+  return -1;
+}
+
+int _unlink(const char *path);
+int
+_unlink (const char *path)
+{
+  UNUSED_PARAM(path);
+  return -1;
+}
+
+void _raise(void);
+void
+_raise (void)
+{
+  return;
+}
+
+int _gettimeofday(struct timeval *tp, struct timezone *tzp);
+int
+_gettimeofday (struct timeval *tp,
+	       struct timezone *tzp)
+{
+
+  if(tp)
+    {
+      tp->tv_sec = 0;
+      tp->tv_usec = 0;
+    }
+  /* Return fixed data for the timezone.  */
+  if (tzp)
+    {
+      tzp->tz_minuteswest = 0;
+      tzp->tz_dsttime = 0;
+    }
+
+  return 0;
+}
+
+/* Return a clock that ticks at 100Hz.  */
+clock_t _times(struct tms *tp);
+clock_t
+_times (struct tms * tp)
+{
+  clock_t timeval = 0;
+
+  if (tp)
+    {
+      tp->tms_utime  = timeval;	/* user time */
+      tp->tms_stime  = 0;	/* system time */
+      tp->tms_cutime = 0;	/* user time, children */
+      tp->tms_cstime = 0;	/* system time, children */
+    }
+
+  return timeval;
+};
+
+
+int isatty(int fd);
+int
+isatty (int fd)
+{
+  UNUSED_PARAM(fd);
+  return 1;
+}
+
+int _system(const char *s);
+int
+_system (const char *s)
+{
+  UNUSED_PARAM(s);
+  return -1;
+}
+
+int _rename(const char *oldpath, const char *newpath);
+int
+_rename (const char * oldpath, const char * newpath)
+{
+  UNUSED_PARAM(oldpath);
+  UNUSED_PARAM(newpath);
+  return -1;
+}
+
+/* extern (.*) ([^ ]*) _PARAMS \(\(struct _reent \*(,*)(.*)\)\); */
+/* \1 \2 (struct _reent *\3\4) { return \2(\4);} */
+
+struct _reent;
+
+int _close_r(struct _reent *reent, int file)
+{ UNUSED_PARAM(reent); return _close(file);}
+/*
+  int _fcntl_r(struct _reent *, int, int, int)
+  { return _fcntl( int, int, int);}
+*/
+int _fstat_r(struct _reent *reent, int file, struct stat *st);
+int _fstat_r(struct _reent *reent, int file, struct stat *st)
+{ UNUSED_PARAM(reent); return _fstat(file, st);}
+
+int _getpid_r(struct _reent *reent);
+int _getpid_r(struct _reent *reent)
+{ UNUSED_PARAM(reent); return _getpid();}
+
+int _kill_r(struct _reent *reent, int n, int m);
+int _kill_r(struct _reent *reent, int n, int m)
+{ UNUSED_PARAM(reent); return _kill(n, m);}
+
+int _link_r(struct _reent *reent, const char *path1, const char *path2);
+int _link_r(struct _reent *reent, const char *path1, const char *path2)
+{ UNUSED_PARAM(reent); return _link(path1, path2);}
+
+_off_t _lseek_r(struct _reent *reent, int file, _off_t pos, int dir);
+_off_t _lseek_r(struct _reent *reent, int file, _off_t pos, int dir)
+{ UNUSED_PARAM(reent); return _lseek(file, pos, dir);}
+
+int _open_r(struct _reent *reent, const char *path, int flags, int opts);
+int _open_r(struct _reent *reent, const char *path, int flags, int opts)
+{ UNUSED_PARAM(reent); return _openat(TARGET_AT_FDCWD, path, flags, opts);}
+
+int _openat_r(struct _reent *reent, int fd, const char *path, int flags, int opts);
+int _openat_r(struct _reent *reent, int fd, const char *path, int flags, int opts)
+{ UNUSED_PARAM(reent); return _openat(fd, path, flags, opts);}
+
+_ssize_t _read_r(struct _reent *reent, int file, void *ptr, size_t len);
+_ssize_t _read_r(struct _reent *reent, int file, void *ptr, size_t len)
+{ UNUSED_PARAM(reent); return _read(file, ptr, len);}
+
+void *_sbrk_r(struct _reent *reent, ptrdiff_t incr);
+void *_sbrk_r(struct _reent *reent, ptrdiff_t incr)
+{ UNUSED_PARAM(reent); return _sbrk(incr);}
+
+int _stat_r(struct _reent *reent, const char *path, struct stat *st);
+int _stat_r(struct _reent *reent, const char *path, struct stat *st)
+{ UNUSED_PARAM(reent); return _stat(path, st);}
+
+int _unlink_r(struct _reent *reent, const char *path);
+int _unlink_r(struct _reent *reent, const char *path)
+{ UNUSED_PARAM(reent); return _unlink(path);}
+
+_ssize_t _write_r(struct _reent *reent, int file, const void *ptr, size_t len);
+_ssize_t _write_r(struct _reent *reent, int file, const void *ptr, size_t len)
+{ UNUSED_PARAM(reent); return _write(file, ptr, len);}
+
+/* FIXME: TDK added dummy functions. Need to implement. */
+int _isatty(int fd);
+int _isatty(int fd)
+{
+  UNUSED_PARAM(fd);
+  return -1;
+}
+
+int _swistat(int fd, struct stat *st);
+int _swistat(int fd, struct stat *st)
+{
+  UNUSED_PARAM(fd);
+  UNUSED_PARAM(st);
+  return -1;
+}
+
+/* Return a clock that ticks at 100Hz.  */
+clock_t _clock(void);
+clock_t _clock(void)
+{
+  clock_t timeval=0;
+  return timeval;
+}
+
+int _swiclose(int fh);
+int _swiclose(int fh)
+{
+  UNUSED_PARAM(fh);
+  return -1;
+}
+
+int _swiopen(const char *path, int flags);
+int _swiopen(const char *path, int flags)
+{
+  UNUSED_PARAM(path);
+  UNUSED_PARAM(flags);
+  return -1;
+}
+
+int _swiwrite(int fh, char *ptr, int len);
+int _swiwrite(int fh, char *ptr, int len)
+{
+  UNUSED_PARAM(fh);
+  UNUSED_PARAM(ptr);
+  UNUSED_PARAM(len);
+  return -1;
+}
+
+int _swilseek(int fd, int ptr, int dir);
+int _swilseek(int fd, int ptr, int dir)
+{
+  UNUSED_PARAM(fd);
+  UNUSED_PARAM(ptr);
+  UNUSED_PARAM(dir);
+  return -1;
+}
+
+int _swiread(int fh, char *ptr,	int len);
+int _swiread(int fh, char *ptr,	int len)
+{
+  UNUSED_PARAM(fh);
+  UNUSED_PARAM(ptr);
+  UNUSED_PARAM(len);
+  return -1;
+}
+
+void initialise_monitor_handles(void);
+void initialise_monitor_handles(void)
+{
+}

seminaries/hello-apo/sys-qtrvsim/qtrvsim_unistd.h

+// ******************************************************************
+//  QtRvSim emulator https://github.com/cvut/qtrvsim support filees
+//
+//  qtrvsim_unistd.h  - definition of the QtRvSim syscall numbers
+//
+//  (C) Copyright 2019 - 2022 by Pavel Pisa
+//      e-mail:   pisa@cmp.felk.cvut.cz
+//      homepage: http://cmp.felk.cvut.cz/~pisa
+//      license:  any combination of GPL, LGPL, MPL or BSD licenses
+//
+// ******************************************************************
+
+#ifndef QTRVSIM_UNISTD_H
+#define QTRVSIM_UNISTD_H
+
+// Linux kernel compatible system calls subset
+
+#define __NR_exit         93  // void exit(int status)
+#define __NR_read         63  // ssize_t read(int fd, void *buf, size_t count)
+#define __NR_write        64  // ssize_t write(int fd, const void *buf, size_t count)
+#define __NR_close        57  // int close(int fd)
+#define __NR_openat       56  // int openat(int fd, const char *pathname, int flags, mode_t mode)
+        // use fd = -100 for normal open behaviour. Full openat not supported.
+#define __NR_brk         214 // void * brk(void *addr)
+#define __NR_ftruncate64  46  // int ftruncate64(int fd, off_t length)
+#define __NR_readv        65  // ssize_t readv(int fd, const struct iovec *iov, int iovcnt)
+#define __NR_writev       66  // ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
+
+#endif /*QTRVSIM_UNISTD_H*/

seminaries/mars/branch_predictors/branch_predictors.asm

+start:
+	addi $v0, $zero, 0	# cycles = 0
+
+	addi $s1, $zero, 3
+L1: # for (i = 3; i !=0; i--)
+	addi $s2, $zero, 5	# i = 3
+L2: # for (j = 5; j !=0; j--)
+	addi $s3, $zero, 4
+L3: # for (k = 4; k !=0; k--)
+	addi $v0, $v0, 1	# cycles++
+	addi $s3, $s3, -1	# k--
+	bne  $s3, $zero, L3	# if (k != 0) goto L3
+
+	addi $s2, $s2, -1	# j--
+	bne  $s2, $zero, L2	# if (j != 0) goto L2
+
+	addi $s1, $s1, -1	# i--
+	bne  $s1, $zero, L1	# if (i != 0) goto L1
+
+	break

seminaries/mars/mars.url

+http://courses.missouristate.edu/kenvollmar/mars/

seminaries/mzapo/lcd/mzapo_lcdip/mzapo_lcdip.c

@@ -4,7 +4,7 @@
 
   mzapo_lcdip.c       - main and only file
 
-  (C) Copyright 2004 - 2017 by Pavel Pisa
+  (C) Copyright 2004 - 2020 by Pavel Pisa
       edit:     jiri hubacek <hubacji1@fel.cvut.cz>
       e-mail:   pisa@cmp.felk.cvut.cz
       homepage: http://cmp.felk.cvut.cz/~pisa
@@ -15,6 +15,10 @@
 
 #define _POSIX_C_SOURCE 200112L
 
+//#define HX8357_B
+//#define ILI9481
+
+
 #include <sys/mman.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -48,6 +52,7 @@ char *memdev="/dev/mem";
 #define PARLCD_REG_BASE_PHYS 0x43c00000
 #define PARLCD_REG_SIZE      0x00004000
 
+#define PARLCD_REG_CR_o                 0x0000
 #define PARLCD_REG_CMD_o                0x0008
 #define PARLCD_REG_DATA_o               0x000C
 
@@ -81,6 +86,11 @@ void *map_phys_address(off_t region_base, size_t region_size, int opt_cached)
   return mem;
 }
 
+void parlcd_write_cr(unsigned char *parlcd_mem_base, uint16_t data)
+{
+  *(volatile uint16_t*)(parlcd_mem_base + PARLCD_REG_CR_o) = data;
+}
+
 void parlcd_write_cmd(unsigned char *parlcd_mem_base, uint16_t cmd)
 {
   *(volatile uint16_t*)(parlcd_mem_base + PARLCD_REG_CMD_o) = cmd;
@@ -117,7 +127,76 @@ void parlcd_hx8357_init(unsigned char *parlcd_mem_base)
     parlcd_write_cmd(parlcd_mem_base, 0x1);
     parlcd_delay(30);
 
-#ifdef HX8357_B
+#if defined(ILI9481)
+// Configure ILI9481 display
+
+    parlcd_write_cmd(parlcd_mem_base, 0x11);
+    parlcd_delay(20);
+    parlcd_write_cmd(parlcd_mem_base, 0xD0);
+    parlcd_write_data(parlcd_mem_base, 0x07);
+    parlcd_write_data(parlcd_mem_base, 0x42);
+    parlcd_write_data(parlcd_mem_base, 0x18);
+
+    parlcd_write_cmd(parlcd_mem_base, 0xD1);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+    parlcd_write_data(parlcd_mem_base, 0x07);
+    parlcd_write_data(parlcd_mem_base, 0x10);
+
+    parlcd_write_cmd(parlcd_mem_base, 0xD2);
+    parlcd_write_data(parlcd_mem_base, 0x01);
+    parlcd_write_data(parlcd_mem_base, 0x02);
+
+    parlcd_write_cmd(parlcd_mem_base, 0xC0);
+    parlcd_write_data(parlcd_mem_base, 0x10);
+    parlcd_write_data(parlcd_mem_base, 0x3B);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+    parlcd_write_data(parlcd_mem_base, 0x02);
+    parlcd_write_data(parlcd_mem_base, 0x11);
+
+    parlcd_write_cmd(parlcd_mem_base, 0xC5);
+    parlcd_write_data(parlcd_mem_base, 0x03);
+
+    parlcd_write_cmd(parlcd_mem_base, 0xC8);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+    parlcd_write_data(parlcd_mem_base, 0x32);
+    parlcd_write_data(parlcd_mem_base, 0x36);
+    parlcd_write_data(parlcd_mem_base, 0x45);
+    parlcd_write_data(parlcd_mem_base, 0x06);
+    parlcd_write_data(parlcd_mem_base, 0x16);
+    parlcd_write_data(parlcd_mem_base, 0x37);
+    parlcd_write_data(parlcd_mem_base, 0x75);
+    parlcd_write_data(parlcd_mem_base, 0x77);
+    parlcd_write_data(parlcd_mem_base, 0x54);
+    parlcd_write_data(parlcd_mem_base, 0x0C);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+
+    parlcd_write_cmd(parlcd_mem_base, 0x36);
+    //parlcd_write_data(parlcd_mem_base, 0x0A);
+    parlcd_write_data(parlcd_mem_base, 0x28);
+
+    parlcd_write_cmd(parlcd_mem_base, 0x3A);
+    parlcd_write_data(parlcd_mem_base, 0x55);
+
+    //parlcd_write_cmd(parlcd_mem_base, 0x2A);
+    parlcd_write_cmd(parlcd_mem_base,  0x2B);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+    parlcd_write_data(parlcd_mem_base, 0x01);
+    parlcd_write_data(parlcd_mem_base, 0x3F);
+
+    //parlcd_write_cmd(parlcd_mem_base, 0x2B);
+    parlcd_write_cmd(parlcd_mem_base,  0x2A);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+    parlcd_write_data(parlcd_mem_base, 0x00);
+    parlcd_write_data(parlcd_mem_base, 0x01);
+    parlcd_write_data(parlcd_mem_base, 0xDF);
+
+    parlcd_delay(120);
+    parlcd_write_cmd(parlcd_mem_base, 0x29);
+
+    parlcd_delay(25);
+
+#elif defined(HX8357_B)
 // Configure HX8357-B display
     parlcd_write_cmd(parlcd_mem_base, 0x11);
     parlcd_delay(20);
@@ -297,13 +376,19 @@ int main(int argc, char *argv[])
   unsigned char *parlcd_mem_base;
   int i, j, k, blank;
   unsigned c;
-  unsigned ip_address;
+  unsigned ip_address = 0;
 
   uint8_t ip_bit, ip_byte_num, bl_y;
 
   struct ifaddrs *ifa = NULL;
   struct ifaddrs *ifa_it;
 
+  int lcd_hw_reset = 0;
+
+  if (argc >= 2)
+    if(!strcmp(argv[1], "reset"))
+      lcd_hw_reset = 1;
+
   if (getifaddrs(&ifa)) {
     return -1;
   }
@@ -331,6 +416,13 @@ int main(int argc, char *argv[])
   if (parlcd_mem_base == NULL)
     exit(1);
 
+  if (lcd_hw_reset) {
+    parlcd_write_cr(parlcd_mem_base, 2);
+    parlcd_delay(100);
+    parlcd_write_cr(parlcd_mem_base, 0);
+    parlcd_delay(100);
+  }
+
   parlcd_hx8357_init(parlcd_mem_base);
   parlcd_hx8357_init(parlcd_mem_base);