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-rw-r--r--demo/console.c145
-rw-r--r--demo/demo.h34
-rw-r--r--demo/link.ld33
-rw-r--r--demo/lock.S26
-rw-r--r--demo/main.c44
-rw-r--r--demo/smp.c43
-rw-r--r--demo/start.S57
-rw-r--r--demo/util.c7
8 files changed, 389 insertions, 0 deletions
diff --git a/demo/console.c b/demo/console.c
new file mode 100644
index 0000000..e531b2e
--- /dev/null
+++ b/demo/console.c
@@ -0,0 +1,145 @@
+#include <stdarg.h>
+
+#include "demo.h"
+
+struct lock console_lock;
+
+#define JTAG_UART_BASE 0x30000000
+#define JTAG_UART_DATA (*(volatile unsigned *)(JTAG_UART_BASE + 0))
+#define JTAG_UART_CONTROL (*(volatile unsigned *)(JTAG_UART_BASE + 4))
+#define JTAG_UART_CONTROL_RE (1 << 0)
+#define JTAG_UART_CONTROL_AC (1 << 10)
+#define JTAG_UART_CONTROL_WSPACE 0xffff0000
+
+#define INTC_BASE 0x30070000
+#define INTC_MASK (*(volatile unsigned *)(INTC_BASE + 4))
+#define INTC_MASK_TIMER (1 << 0)
+#define INTC_MASK_UART (1 << 1)
+
+static void print_char(char c)
+{
+ while (!(JTAG_UART_CONTROL & JTAG_UART_CONTROL_WSPACE));
+ JTAG_UART_DATA = (unsigned char)c;
+}
+
+static void print_str(const char *s)
+{
+ while (*s)
+ print_char(*s++);
+}
+
+static void print_hex(unsigned val, unsigned bits)
+{
+ static const char hex_digits[16] = "0123456789abcdef";
+
+ print_str("0x");
+
+ if (bits < 4)
+ bits = 4;
+
+ if (bits > 32)
+ bits = 32;
+
+ bits = bits & ~3;
+ do
+ print_char(hex_digits[(val >> (bits -= 4)) & 0xf]);
+ while (bits);
+}
+
+static void print_dec(unsigned val)
+{
+ char dec[11] = {'\0'};
+ char *next = dec;
+
+ do {
+ *next++ = '0' + val % 10;
+ val /= 10;
+ } while (val && next < dec + sizeof dec);
+
+ const char *c = next;
+ while (c > dec)
+ print_char(*--c);
+}
+
+void console_init(void)
+{
+ spin_init(&console_lock);
+
+ // Habilitar irqs de entrada uart
+ JTAG_UART_CONTROL = JTAG_UART_CONTROL_RE;
+
+ // Habilitar irqs en controlador de interrupciones
+ INTC_MASK = INTC_MASK_UART;
+
+ // Habilitar irqs en core
+ asm volatile("msr cpsr_c, #0x53");
+}
+
+void print(const char *fmt, ...)
+{
+ va_list args;
+ va_start(args, fmt);
+
+ unsigned irq_save;
+ spin_lock(&console_lock, &irq_save);
+
+ while (!(JTAG_UART_CONTROL & JTAG_UART_CONTROL_AC));
+
+ print_str("cpu");
+ print_dec(this_cpu->num);
+ print_str(": ");
+
+ char c;
+ while ((c = *fmt++)) {
+ if (c != '%') {
+ print_char(c);
+ continue;
+ }
+
+ unsigned val;
+ switch ((c = *fmt++)) {
+ case 'c':
+ print_char((char)va_arg(args, int));
+ break;
+
+ case 'd':
+ case 'i':
+ print_dec((unsigned)va_arg(args, int));
+ break;
+
+ case 'p':
+ print_hex((unsigned)va_arg(args, const void *), 32);
+ break;
+
+ case 'r':
+ val = va_arg(args, unsigned);
+ print_hex(val, va_arg(args, unsigned));
+ break;
+
+ case 'u':
+ print_dec(va_arg(args, unsigned));
+ break;
+
+ case 's':
+ print_str(va_arg(args, const char *));
+ break;
+
+ case 'x':
+ print_hex(va_arg(args, unsigned), 32);
+ break;
+
+ default:
+ print_char('%');
+ if (c)
+ print_char(c);
+
+ break;
+ }
+ }
+
+ print_str("\r\n");
+ JTAG_UART_CONTROL = JTAG_UART_CONTROL_RE | JTAG_UART_CONTROL_AC;
+
+ spin_unlock(&console_lock, irq_save);
+ va_end(args);
+}
diff --git a/demo/demo.h b/demo/demo.h
new file mode 100644
index 0000000..1bff8d6
--- /dev/null
+++ b/demo/demo.h
@@ -0,0 +1,34 @@
+#ifndef DEMO_H
+#define DEMO_H
+
+#define NUM_CPUS 4
+
+struct lock
+{
+ volatile unsigned val;
+};
+
+struct cpu
+{
+ unsigned num;
+};
+
+/* R12 está reservado por la ABI
+ * https://gcc.gnu.org/onlinedocs/gcc/Global-Register-Variables.html
+ */
+register struct cpu *this_cpu asm("ip");
+
+void spin_init(struct lock *lock);
+void spin_lock(struct lock *lock, unsigned *irq_save);
+void spin_unlock(struct lock *lock, unsigned irq_save);
+
+void console_init(void);
+void print(const char *fmt, ...);
+
+int cpus_ready(void);
+void run_cpu(unsigned num);
+void run_cpus(unsigned mask);
+void halt_cpu(unsigned num);
+void halt_cpus(unsigned mask);
+
+#endif
diff --git a/demo/link.ld b/demo/link.ld
new file mode 100644
index 0000000..5f400c7
--- /dev/null
+++ b/demo/link.ld
@@ -0,0 +1,33 @@
+MEMORY
+{
+ HPS_SDRAM (rwx) : ORIGIN = 0x00000000, LENGTH = 512M
+}
+
+SECTIONS
+{
+ ._img :
+ {
+ KEEP(*(.interrupt_vector))
+ *(.text)
+ *(.text*)
+ *(.rodata)
+ *(.rodata*)
+ *(.data)
+ *(.data*)
+ *(.bss)
+ *(.bss*)
+ *(COMMON)
+ . = ALIGN(4);
+ } > HPS_SDRAM
+
+ _stack_shift = 13;
+ _stack_size = (1 << _stack_shift) * 4;
+ _stack_end = ORIGIN(HPS_SDRAM) + LENGTH(HPS_SDRAM);
+ _stack_begin = (_stack_end - _stack_size) + (1 << _stack_shift);
+
+ . = _stack_begin;
+ ._stack :
+ {
+ . = . + _stack_size;
+ } > HPS_SDRAM
+}
diff --git a/demo/lock.S b/demo/lock.S
new file mode 100644
index 0000000..3ec2765
--- /dev/null
+++ b/demo/lock.S
@@ -0,0 +1,26 @@
+.global spin_init
+spin_init:
+ mov r1, #0
+ str r1, [r0]
+ mov pc, lr
+
+.global spin_lock
+spin_lock:
+ mrs r2, cpsr
+ str r2, [r1]
+ orr r2, r2, #0xc0 @ Levanta I, F
+ msr cpsr_c, r2
+ mov r3, #1
+1: ldrex r2, [r0]
+ teq r2, #0
+ strexeq r2, r3, [r0]
+ teqeq r2, #0
+ bne 1b
+ mov pc, lr
+
+.global spin_unlock
+spin_unlock:
+ mov r2, #0
+ str r2, [r0]
+ msr cpsr_c, r1
+ mov pc, lr
diff --git a/demo/main.c b/demo/main.c
new file mode 100644
index 0000000..b984d6f
--- /dev/null
+++ b/demo/main.c
@@ -0,0 +1,44 @@
+#include "demo.h"
+
+static struct cpu cpu0, cpu1, cpu2, cpu3;
+
+struct cpu *__cpus[] = { &cpu0, &cpu1, &cpu2, &cpu3 };
+
+void bsp_main(void)
+{
+ run_cpu(1);
+
+ while (!cpus_ready());
+ print("booted %u cpus", NUM_CPUS);
+
+ while (1) {
+ }
+}
+
+void ap_main(void)
+{
+ if (this_cpu->num < NUM_CPUS - 1)
+ run_cpu(this_cpu->num + 1);
+
+ halt_cpu(this_cpu->num);
+
+ while (1) {
+ }
+}
+
+void reset(void)
+{
+ if (this_cpu->num == 0) {
+ console_init();
+
+ for (struct cpu **cpu = __cpus; cpu < __cpus + NUM_CPUS; ++cpu) {
+ }
+ }
+
+ print("core taken out of reset");
+
+ if (this_cpu->num == 0)
+ bsp_main();
+ else
+ ap_main();
+}
diff --git a/demo/smp.c b/demo/smp.c
new file mode 100644
index 0000000..f0f83e7
--- /dev/null
+++ b/demo/smp.c
@@ -0,0 +1,43 @@
+#include "demo.h"
+
+#define SMP_CTRL_BASE 0x30140000
+#define SMP_CTRL (*(volatile unsigned *)SMP_CTRL_BASE)
+
+int cpus_ready(void)
+{
+ return SMP_CTRL == 0;
+}
+
+void run_cpu(unsigned num)
+{
+ run_cpus(1 << num);
+}
+
+void run_cpus(unsigned mask)
+{
+ unsigned ctrl_word = 0;
+ for (unsigned cpu = 0; cpu < NUM_CPUS; ++cpu)
+ if (mask & (1 << cpu)) {
+ print("run cpu%u", cpu);
+ ctrl_word |= 0b001 << (cpu * 8);
+ }
+
+ SMP_CTRL = ctrl_word;
+}
+
+void halt_cpu(unsigned num)
+{
+ halt_cpu(1 << num);
+}
+
+void halt_cpus(unsigned mask)
+{
+ unsigned ctrl_word = 0;
+ for (unsigned cpu = 0; cpu < NUM_CPUS; ++cpu)
+ if (mask & (1 << cpu)) {
+ print("halt cpu%u%s", cpu, cpu == this_cpu->num ? " (myself)" : "");
+ ctrl_word |= 0b010 << (cpu * 8);
+ }
+
+ SMP_CTRL = ctrl_word;
+}
diff --git a/demo/start.S b/demo/start.S
new file mode 100644
index 0000000..6e5e457
--- /dev/null
+++ b/demo/start.S
@@ -0,0 +1,57 @@
+.section .interrupt_vector
+
+__reset:
+ b _start
+
+__undefined:
+ b undefined
+
+__swi:
+ b swi
+
+__prefetch_abort:
+ b prefetch_abort
+
+__data_abort:
+ b data_abort
+
+__reserved:
+ b .
+
+__irq:
+ b irq
+
+__fiq:
+ b .
+
+.text
+
+.global _start
+_start:
+ ldr r0, =_boot_num
+ ldr r1, [r0]
+ add r2, r1, #1
+ str r2, [r0]
+ ldr r2, =__cpus
+ lsl r3, r1, #2
+ ldr ip, [r2, r3]
+ str r1, [ip]
+ ldr r2, =_stack_shift
+ lsl r1, r1, r2
+ ldr sp, =_stack_begin
+ add sp, sp, r1
+ mov lr, #0
+ bl reset
+ b .
+
+_boot_num:
+ .word 0
+
+irq:
+ subs pc, lr, #4
+
+.weak undefined, swi, data_abort, prefetch_abort, irq
+.set swi, __swi
+.set undefined, __undefined
+.set data_abort, __data_abort
+.set prefetch_abort, __prefetch_abort
diff --git a/demo/util.c b/demo/util.c
new file mode 100644
index 0000000..457a32c
--- /dev/null
+++ b/demo/util.c
@@ -0,0 +1,7 @@
+int strcmp(const char *s1, const char *s2)
+{
+ while (*s1 && *s1 == *s2)
+ s1++, s2++;
+
+ return (int)*(const unsigned char *)s1 - (int)*(const unsigned char *)s2;
+}
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