Browse Source

Update to work on real hardware

master
Ilja Kartašov 3 years ago
parent
commit
21a25ec4e8
  1. 4
      Makefile
  2. 11
      Makevars.mk
  3. 14
      README.md
  4. 3
      config.txt
  5. 79
      docs/coding-style.md
  6. 0
      docs/memory-management.md
  7. 0
      docs/naming-convention.md
  8. 10
      docs/project-structure.md
  9. 0
      docs/task-scheduling.md
  10. 6
      kernel/Makefile
  11. 21
      kernel/aarch64/aarch64.S
  12. 4
      kernel/aarch64/aarch64.h
  13. 7
      kernel/config.mk
  14. 51
      kernel/drivers/timer/timer.c
  15. 9
      kernel/leos/irq.c
  16. 2
      kernel/leos/irq.h
  17. 37
      kernel/leos/leos.c
  18. 13
      kernel/leos/memory.c
  19. 4
      kernel/leos/memory.h
  20. 130
      kernel/leos/task.c
  21. 8
      kernel/leos/task.h

4
Makefile

@ -1,4 +1,6 @@
include Makevars.mk
ROOT = ./
include ${ROOT}Makevars.mk
# Rules
#

11
Makevars.mk

@ -3,6 +3,8 @@
# Ilja Kartašov, 2019-11-29 17:38
#
include ${ROOT}kernel/config.mk
BUILD_DIR ?= build/
AARCH64_TOOLCHAIN ?= aarch64-linux-gnu
@ -33,3 +35,12 @@ AARCH64_QEMU = \
# -kernel /home/elias/git/rpi/boards/pi3/aarch64/uart02/kernel8.img \
# vim:ft=make
#
CONFIG_CFLAGS = -D"CONFIG_ARCH=\"${CONFIG_ARCH}\""
CONFIG_CFLAGS = -DCONFIG_ARM_TIMER=${CONFIG_ARM_TIMER}
#ifeq (${CONFIG_HARDWARE}, rpi3)
#CONFIG_CFLAGS += -DCONFIG_HARDWARE_RPI3=1
#else ifeq (${CONFIG_HARDWARE}, qemu)
#CONFIG_CFLAGS += -DCONFIG_HARDWARE_QEMU=1
#endif

14
README.md

@ -1,4 +1,4 @@
# Leos
# LeOS
Operating System for ARMv8 (aarch64) Architecture
* [The Idea](#The Idea)
@ -33,9 +33,9 @@ Early development is going for **Raspberry PI3** board and its emulation using
## Documentation
* [Project structure](docs/project-structure.md)
* [Naming convention](docs/naming-convention.md)
* [Task scheduling](docs/task-scheduling.md)
* [Memory management](docs/memory-management.md)
* [Coding style](docs/coding-style.md)
* Task scheduling
* Memory management
## Compilation
@ -56,7 +56,7 @@ To run Löwe OS on Raspberry PI3, follow these steps:
1. Compile project and copy `build/kernel8.img` and `config.txt` files to
Micro SD card
2. Make sure latest boot code is installed on the SD card
2. Make sure latest `bootcode.bin` and `start.elf` files are copied to the SD card
3. Insert SD card into your Raspberry PI3 and power it up
## Debug
@ -72,8 +72,8 @@ easy as `make debug`.
[x] Memory pages avalability bitmap
[x] Interrupt vectors table
[x] Basic task scheduler
[ ] Context switching
[ ] Memory Mapping Unit
[x] Context switching
[ ] MMU and entering user level
2. Input/output:
[ ] Graphical driver
[ ] USB driver

3
config.txt

@ -0,0 +1,3 @@
arm_control=0x200
kernel_old=1
disable_commandline_tags=1

79
docs/coding-style.md

@ -0,0 +1,79 @@
# LeOS Coding Style
## Files names
1. Only lower case
2. Words separated with underscore:
```
aarch64/aarch64_boot.S
```
## Preprocessor macro constants
1. Only upper case
2. Words separated with underscore:
```
#define AARCH64_CORE0_TIMER_IRQCTL (*((uint32_t *) 0x40000040))
```
## Types
1. Camel case started from upper case
2. Do not typedef transparent structures
3. Members of structre should be named in camel case started from lower case
```
struct Task {
void *sp;
void *stackStart;
uint32_t pid;
uint32_t stackSize;
uint32_t lock;
uint32_t counter;
uint32_t cycles;
int32_t priority;
uint32_t state;
char name[CONFIG_TASK_MAX_NAME_LEN + 1];
struct Task *next;
};
```
## Constants and variables
1. Global constants and variablesmust be prefixed with `g_`
2. Module (static) constants and variable must be prefixed `m_`
3. Camel case
```
static struct Task *m_currentTask = NULL;
```
## Functions
1. Camel case
2. Prefix separated from function identifier by underscore
3. Static functions may have no prefix
4. Prefix always starts from capital letter
5. Function identifier always starts from lower case verb
```
unsigned int
AArch64_getEL(void);
static struct Task *
scheduleNext(void);
```
## Namespaces and prefixes
1. Due to C has no native namespaces, prefixes should always be used
2. Prefix should match with file name
```
/* file : task.h */
void
Task_initSheduler(void);
```

0
docs/memory-management.md

0
docs/naming-convention.md

10
docs/project-structure.md

@ -0,0 +1,10 @@
# Project Structure
* `build/` - temporary output folder
* `docs/` - documentation folder
* `kernel/` - kernel source codes
* `aarch64/` - core AArch64 architecture code
* `drivers/` - code for various drivers
* `leos/` - code of the core LeOS features
* `Makefile` - kernel specific makefile
* `Makefile` - root project makefile

0
docs/task-scheduling.md

6
kernel/Makefile

@ -1,6 +1,8 @@
# environment
include ../Makevars.mk
ROOT = ../
include ${ROOT}Makevars.mk
# CFLAGS
@ -65,5 +67,5 @@ $(BUILD_DIR)kernel.sym: $(BUILD_DIR)/kernel.elf
$(BUILD_DIR)%.o: %
$(info compiling file: $<)
@mkdir -p $(dir ./$(BUILD_DIR)$<)
$(AARCH64_CC) $(INCS) $(CFLAGS) -c $< -o $@
$(AARCH64_CC) $(INCS) $(CFLAGS) $(CONFIG_CFLAGS) -c $< -o $@

21
kernel/aarch64/aarch64.S

@ -125,13 +125,25 @@ die:
.globl AArch64_startTask
AArch64_startTask:
bl Task_unlockScheduler
blr x1
mov x0, x20
blr x21
hang:
/* todo: implement task exit here */
WFE
b hang
.globl AArch64_getPState
AArch64_getPState:
mrs x23, NZCV
mrs x3, DAIF
orr x23, x23, x3
mrs x3, CurrentEL
lsr x3, x3, 0x02
/* set third bit: todo: find out its real meaning (registers width?) */
orr x3, x3, 0x04
orr x0, x23, x3
ret
.globl AArch64_switchContext
AArch64_switchContext:
@ -157,6 +169,7 @@ AArch64_switchContext:
mrs x3, DAIF
orr x23, x23, x3
mrs x3, CurrentEL
lsr x3, x3, 0x02
orr x23, x23, x3
stp x30, x30, [sp, 16 * 15]
@ -227,9 +240,11 @@ el1h_sync:
el1h_irq:
SAVE_REGISTERS
mov x0, sp
bl Task_setStackPointer
bl IRQ_onInterrupt
cbz x0, load_regs
mov sp, x0 /* task context must be switched */
bl Task_getStackPointer
mov sp, x0
load_regs:
LOAD_REGISTERS
eret

4
kernel/aarch64/aarch64.h

@ -16,6 +16,7 @@
#ifndef AARCH64_H_F3AA8888_CEB3_4C16_9835_C3F23B040BB5
#define AARCH64_H_F3AA8888_CEB3_4C16_9835_C3F23B040BB5
#include <leos/types.h>
#include "aarch64_reg.h"
#include "aarch64_irq.h"
@ -46,6 +47,9 @@ AArch64_memzero(void *addr, unsigned long size);
extern void
AArch64_startTask(void *arg, void *callback);
extern uint32_t
AArch64_getPState(void);
extern void
AArch64_switchContext(void *currentTask, void *nextTask);

7
kernel/config.mk

@ -0,0 +1,7 @@
# Target architecture (AARCH64)
CONFIG_ARCH = AARCH64
# Use ARM local timer (1/0)
CONFIG_ARM_TIMER = 0
-include config.dev.mk

51
kernel/drivers/timer/timer.c

@ -18,38 +18,15 @@
#include <leos/log.h>
#include "timer.h"
const unsigned int m_interval = 2000000;
unsigned int m_current = 0;
#ifndef CONFIG_ARM_TIMER
#define CONFIG_ARM_TIMER 1
#if CONFIG_ARM_TIMER == 1
const unsigned int m_interval = 500000000;
#else
const unsigned int m_interval = 200000;
#endif
unsigned int m_current = 0;
#define TIMER_ENABLE ((1 << 31) | (1 << 29) | (1 << 28))
#define TIMER_RELOAD 1
/*
* https://www.raspberrypi.org/forums/viewtopic.php?t=213393
* The sequence on a real PI3 is
* 1.) Route the local timer to a core register 0x40000024 (bits 0..2)
* QA7_rev3.4.pdf page 18 ... say write 0 which is core 0
*
* 2.) Setup timer status control register 0x40000034 (all 32 bits)
* QA7_rev3.4.pdf page 17 ... reload value 5000000 = like half sec, enable clock, enable interrupt
* You can play with clock prescalers etc later.
* 3.) Hit timer interrupt clear and reload register 0x40000038 (bits 30 & 31)
* QA7_rev3.4.pdf page 18 ... write 1 to both bits which clears irq signal and loads value from above
*
* 4.) Setup timer interrupt control register 0x40000040 (all bits ... zero all but the one bit set)
* QA7_rev3.4.pdf page 13 ... now this depends what mode Core0 leaves your bootstub in.
* If you did no EL changes in stub the core0 will still be in Hyp mode if like me you dropped it to SVC mode it is Non Secure
*
* If Core0 enters in Hyp mode ... set nCNTHPIRQ_IRQ bit 1
* If Core0 enters in Svc mode ... set nCNTPNSIRQ_IRQ bit 2
*
* 5.) Now you need to enable global interupts
* asm(" cpsie i")
* */
#define TIMER_RELOAD 5000000
void
Timer_init(void)
@ -65,28 +42,24 @@ Timer_init(void)
AARCH64_CORE0_TIMER_IRQCTL = (1 << 1); /* nCNTPNSIR1 - Non Secure*/
#else
m_current = aarch64_get32r(TIMER_CLO);
m_current = AArch64_getReg32(TIMER_CLO);
m_current += m_interval;
aarch64_set32r(TIMER_C1, m_current);
AArch64_setReg32(TIMER_C1, m_current);
#endif
}
void
Timer_incFromISR(void)
{
m_current++; /*= m_interval;*/
m_current += m_interval;
#if CONFIG_ARM_TIMER == 1
/* clear interrupt flag and reload timer */
// AARCH64_LOCAL_TIMER_STATCTL |= TIMER_RELOAD;
AARCH64_LOCAL_TIMER_RECLR |= (1 << 31) | (1 << 30);
#else
aarch64_set32r(TIMER_C1, m_current);
aarch64_set32r(TIMER_CS, TIMER_CS_M1);
AArch64_setReg32(TIMER_C1, m_current);
AArch64_setReg32(TIMER_CS, TIMER_CS_M1);
#endif
/*
Log_putS("--- tick --- ");
Log_putI(m_current, 10);
Log_putS(" ---\r\n");
*/
}
uint32_t

9
kernel/leos/irq.c

@ -39,11 +39,11 @@ static const char *m_types[] = {
};
static void *
static void
IRQ_onTimerInterrupt(void)
{
Timer_incFromISR();
return Task_scheduleFromISR();
Task_scheduleFromISR();
}
void
@ -52,13 +52,15 @@ IRQ_init()
AArch64_setReg32(ENABLE_IRQS_1, SYSTEM_TIMER_IRQ_1);
}
void *
void
IRQ_onInterrupt(void)
{
unsigned int irq = AArch64_getReg32(IRQ_PENDING_1);
switch(irq) {
#if CONFIG_ARM_TIMER == 1
case LOCAL_TIMER_IRQ:
#endif
case SYSTEM_TIMER_IRQ_1:
return IRQ_onTimerInterrupt();
@ -67,7 +69,6 @@ IRQ_onInterrupt(void)
Log_putU(irq, 16);
Log_putS("\n");
}
return 0; /* do not change stack pointer */
}
void

2
kernel/leos/irq.h

@ -21,7 +21,7 @@
void
IRQ_init(void);
void *
void
IRQ_onInterrupt(void);
void

37
kernel/leos/leos.c

@ -13,14 +13,18 @@
* @see https://lowenware.com/
*/
#include <leos/log.h>
#include <leos/irq.h>
#include <leos/leos.h>
#include <leos/log.h>
#include <leos/memory.h>
#include <leos/task.h>
#include <drivers/timer/timer.h>
void
Leos_demoTask(void *arg);
Leos_demoTask1(void *arg);
void
Leos_demoTask2(void *arg);
void
@ -36,27 +40,38 @@ Leos_run(void)
IRQ_init();
Timer_init();
IRQ_enable();
Memory_init();
Task_initSheduler();
if (Task_create(Leos_demoTask, "Task 1") == -1)
IRQ_enable();
if (Task_create(Leos_demoTask1, "T1") == -1)
Log_putS("Task 1 was not created\r\n");
if (Task_create(Leos_demoTask2, "T2") == -1)
Log_putS("Task 2 was not created\r\n");
for (;;) {
Log_putU(Timer_getTicks(), 10);
Log_putS(". Idle Task\r\n");
Log_putS("I");
Task_yield();
}
}
void
Leos_demoTask(void *arg)
Leos_demoTask2(void *arg)
{
for (;;) {
Log_putS("B");
Task_yield();
}
}
void
Leos_demoTask1(void *arg)
{
for (;;) {
Log_putU(Timer_getTicks(), 10);
Log_putS(". ");
Log_putS((const char *)arg);
Log_putS("\r\n");
Log_putS("A");
Task_yield();
}
}

13
kernel/leos/memory.c

@ -15,19 +15,26 @@
*/
#include <stdlib.h>
#include <aarch64/aarch64.h>
#include <drivers/soc/bcm2837/bcm2837.h>
#include "memory.h"
#include "log.h"
static unsigned long m_map[MEMORY_PAGE_COUNT / sizeof(unsigned long) / 8] = {0,};
static int m_ix = 0;
static unsigned long m_map[MEMORY_PAGE_COUNT / sizeof(unsigned long) / 8];
static int m_ix;
void
Memory_init(void)
{
m_ix = 0;
AArch64_memzero(m_map, sizeof(m_map));
}
void *
Memory_getPage(void)
{
int i, j;
unsigned long map;
for (i = m_ix; i < sizeof(m_map) / sizeof(m_map[0]); i++) {
map = m_map[i];

4
kernel/leos/memory.h

@ -16,6 +16,10 @@
#ifndef MEMORY_H_C583E24E_55B0_49EF_99C9_5A36B04468AC
#define MEMORY_H_C583E24E_55B0_49EF_99C9_5A36B04468AC
void
Memory_init(void);
void *
Memory_getPage(void);

130
kernel/leos/task.c

@ -16,11 +16,13 @@
#include <stdlib.h>
#include <aarch64/aarch64.h>
#include <drivers/soc/bcm2837/bcm2837.h>
#include <drivers/timer/timer.h>
#include "memory.h"
#include "log.h"
#include "task.h"
#define TASK_STATE_RUNNING 0
#define TASK_STATE_HALFCYCLE (1 << 8)
#ifndef CONFIG_IDLE_TASK_STACK_SIZE
#define CONFIG_IDLE_TASK_STACK_SIZE 0x4000
@ -46,21 +48,8 @@ struct __attribute__((packed)) TaskContext {
uint64_t spsr_el1;
};
static struct Task *m_currentTask = NULL
, *m_lastTask = NULL
, m_idleTask = {
.sp = NULL
, .stackStart = NULL
, .stackSize = CONFIG_IDLE_TASK_STACK_SIZE
, .pid = 1
, .lock = 1
, .counter = 1
, .cycles = 1
, .priority = 0
, .state = TASK_STATE_RUNNING
, .name = {'I', 'D', 'L', 'E', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
, .next = NULL
};
static struct Task *m_currentTask, *m_lastTask, m_idleTask;
static uint32_t m_pid = 1;
@ -70,7 +59,9 @@ scheduleNext(void)
struct Task *i, *next = NULL;
int32_t priority = -1;
Log_putS("scheduleNext\r\n ");
if (m_currentTask->counter)
m_currentTask->counter--;
for (;;) {
/* check urgent tasks */
for (i = &m_idleTask; i != NULL; i = i->next) {
@ -81,10 +72,6 @@ scheduleNext(void)
priority = i->priority;
next = i;
}
if (!i->state && i->counter > priority) {
priority = i->priority;
next = i;
}
}
if (next) {
@ -96,10 +83,6 @@ scheduleNext(void)
}
}
Log_putS("\t switch: ");
Log_putU((uint64_t)next->pid, 10);
Log_putS("\n");
return next;
}
@ -107,6 +90,24 @@ void
Task_initSheduler(void)
{
struct Task *idleTask = &m_idleTask;
m_pid = 1;
m_idleTask.sp = NULL;
m_idleTask.stackStart = NULL;
m_idleTask.stackSize = CONFIG_IDLE_TASK_STACK_SIZE;
m_idleTask.pid = 1;
m_idleTask.lock = 1;
m_idleTask.counter = 1;
m_idleTask.cycles = 1;
m_idleTask.priority = 0;
m_idleTask.state = TASK_STATE_RUNNING;
m_idleTask.name[0] = 'I';
m_idleTask.name[1] = 'D';
m_idleTask.name[2] = 'L';
m_idleTask.name[3] = 'E';
m_idleTask.name[4] = 0;
m_idleTask.next = NULL;
m_currentTask = idleTask;
m_lastTask = idleTask;
Task_unlockScheduler();
@ -120,6 +121,12 @@ Task_create(TaskCallback callback, void *arg)
if (!task)
return -1;
Log_putS("Task @0x");
Log_putU((uint64_t) task, 16);
Log_putS(" - ");
Log_putU(((uint64_t) task) + MEMORY_PAGE_SIZE, 16);
Log_putS("\r\n");
task->sp = (void *)task + MEMORY_PAGE_SIZE - 272;
task->stackStart = task->sp;
@ -138,10 +145,11 @@ Task_create(TaskCallback callback, void *arg)
task->next = 0;
ctx = (struct TaskContext *) task->sp;
ctx->x[0] = (uint64_t) arg;
ctx->x[1] = (uint64_t) callback;
ctx->x[20] = (uint64_t) arg;
ctx->x[21] = (uint64_t) callback;
ctx->x[30] = (uint64_t) AArch64_startTask;
ctx->elr_el1 = (uint64_t) AArch64_startTask;
ctx->spsr_el1 = AArch64_getPState();
Task_lockScheduler();
m_lastTask->next = task;
@ -154,25 +162,41 @@ Task_create(TaskCallback callback, void *arg)
void
Task_yield(void)
{
struct Task *next, *prev = m_currentTask;
#if 1
uint64_t ticks = Timer_getTicks();
Log_putS("Task_yield()\r\n");
Task_lockScheduler();
Log_putS("^");
m_currentTask->counter = 0;
Task_unlockScheduler();
__asm__("WFE");
while (ticks == Timer_getTicks());
#else
/* Task yield should be solved differently */
struct Task *next, *prev;
Task_lockScheduler();
Log_putS("^");
prev = m_currentTask;
prev->counter = 0;
next = scheduleNext();
if (next != prev) {
next->state |= TASK_STATE_HALFCYCLE;
m_currentTask = next;
Task_unlockScheduler();
AArch64_switchContext(prev, next);
/* newly created tasks never exit here, that is why in AArch64_startTask
* there is own Task_unlockScheduler() call
/* `next` tasks never exits here, but in AArch64_startTask,
* that is why there is an own Task_unlockScheduler() call
* */
} else {
__asm__("WFE");
// __asm__("WFE");
}
Task_unlockScheduler();
#endif
}
void
@ -184,35 +208,55 @@ Task_lockScheduler(void)
void
Task_unlockScheduler(void)
{
m_currentTask->lock--;
if (m_currentTask->lock)
m_currentTask->lock--;
}
void *
void
Task_scheduleFromISR(void)
{
void *sp = NULL;
# if 0
if (m_currentTask->counter)
m_currentTask->counter--;
if (!m_currentTask->lock) {
struct Task *next;
Log_putS("Task_scheduleFromISR\r\n");
if (m_currentTask->state & TASK_STATE_HALFCYCLE) {
m_currentTask->state &= ~TASK_STATE_HALFCYCLE;
return;
}
Log_putS("!");
Task_lockScheduler();
next = scheduleNext();
if (next != m_currentTask) {
m_currentTask = next;
sp = next->sp;
}
/* unlock call could be moved to aarch64.S interrupt handler in case of
* issue
* */
Task_unlockScheduler();
}
#endif
}
void *
Task_getStackPointer(void)
{
/*
Log_putS("gSP:");
Log_putU((uint64_t)m_currentTask->sp, 16);
Log_putS("\r\n");
*/
return m_currentTask->sp;
}
return sp;
void
Task_setStackPointer(void *sp)
{
/*
Log_putS("sSP:");
Log_putU((uint64_t)sp, 16);
Log_putS("\r\n");
*/
m_currentTask->sp = sp;
}

8
kernel/leos/task.h

@ -39,7 +39,13 @@ Task_lockScheduler(void);
void
Task_unlockScheduler(void);
void *
void
Task_scheduleFromISR(void);
void *
Task_getStackPointer(void);
void
Task_setStackPointer(void *sp);
#endif /* !TASK_H */

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