handle irq in the bootloader

sw/bootloader/Makefile

@@ -11,7 +11,7 @@ N64_ELFCOMPRESS = $(N64_BINDIR)/n64elfcompress
 N64_TOOL = $(N64_BINDIR)/n64tool
 PYTHON = python3
 
-FLAGS = -march=vr4300 -mtune=vr4300 $(USER_FLAGS)
+FLAGS = -march=vr4300 -mtune=vr4300 -mfix4300 $(USER_FLAGS)
 CFLAGS = -Os -Wall -ffunction-sections -fdata-sections -ffreestanding -MMD -MP
 ASFLAGS = -Wa,-I$(N64_INST)/mips64-elf/lib
 LDFLAGS = -lc -nostartfiles -Wl,--gc-sections

sw/bootloader/src/display.c

@@ -1,4 +1,3 @@
-#include <stdbool.h>
 #include <stdio.h>
 #include "display.h"
 #include "font.h"
@@ -181,6 +180,10 @@ void display_init (uint32_t *background) {
     }
 }
 
+bool display_ready (void) {
+    return vi_configured;
+}
+
 void display_vprintf (const char *fmt, va_list args) {
     char line[256];
 

sw/bootloader/src/display.h

@@ -3,10 +3,12 @@
 
 
 #include <stdarg.h>
+#include <stdbool.h>
 #include <stdint.h>
 
 
 void display_init (uint32_t *background);
+bool display_ready (void);
 void display_vprintf (const char *fmt, va_list args);
 void display_printf (const char* fmt, ...);
 

sw/bootloader/src/error.c

@@ -1,13 +1,23 @@
 #include <stdarg.h>
-#include "exception.h"
+#include "display.h"
+#include "init.h"
+#include "version.h"
+#include "../assets/assets.h"
 
 
 void error_display (const char *fmt, ...) {
     va_list args;
 
+    deinit();
+
+    display_init((uint32_t *) (&assets_sc64_logo_640_240_dimmed));
+
+    version_print();
+    display_printf("[ Runtime error ]\n");
     va_start(args, fmt);
-    EXCEPTION_TRIGGER(TRIGGER_CODE_ERROR);
+    display_vprintf(fmt, args);
     va_end(args);
+    display_printf("\n");
 
     while (1);
 }

sw/bootloader/src/exception.S

@@ -96,17 +96,11 @@ exception_handler:
     move $sp, $k0
 
 exception_check_type:
-    mfc0 $a0, C0_CAUSE
+    mfc0 $t0, C0_CAUSE
-    sw $a0, C0_CAUSE_OFFSET($k0)
+    sw $t0, C0_CAUSE_OFFSET($k0)
-    move $a1, $a0
+    andi $a0, $t0, C0_CR_EC_MASK
-    move $t0, $a0
+    srl $a0, C0_CR_EC_BIT
-    andi $t0, C0_CR_IP7
+    beqz $a0, exception_interrupt
-    andi $a0, C0_CR_EC_MASK
-    srl $a0, $a0, C0_CR_EC_BIT
-    andi $a1, C0_CR_IP_MASK
-    srl $a1, $a1, C0_CR_IP_BIT
-    bne $t0, $zero, exception_fatal
-    beq $a0, $zero, exception_interrupt
 
 exception_fatal:
     sd $k0, K0_OFFSET($k0)
@@ -117,16 +111,16 @@ exception_fatal:
     sd $t0, C0_EPC_OFFSET($k0)
     dmfc0 $t0, C0_BADVADDR
     sd $t0, C0_BADVADDR_OFFSET($k0)
-    move $a2, $k0
+    move $a1, $k0
-    la $t1, exception_fatal_handler
+    jal exception_fatal_handler
-    jalr $t1
     ld $t0, C0_EPC_OFFSET($k0)
     dmtc0 $t0, C0_EPC
     j exception_restore
 
 exception_interrupt:
-    la $t1, exception_interrupt_handler
+    andi $a0, $t0, C0_CR_IP_MASK
-    jalr $t1
+    srl $a0, C0_CR_IP_BIT
+    jal exception_interrupt_handler
 
 exception_restore:
     .set noat
@@ -169,8 +163,8 @@ exception_enable_interrupts:
     .type exception_enable_interrupts, %function
     .global exception_enable_interrupts
     mfc0 $t0, C0_STATUS
-    li $t1, C0_SR_IE
+    li $t1, (C0_SR_IM4 | C0_SR_IM3 | C0_SR_IE)
-    or $t0, $t0, $t1
+    or $t0, $t1
     mtc0 $t0, C0_STATUS
     jr $ra
 
@@ -180,8 +174,8 @@ exception_disable_interrupts:
     .type exception_disable_interrupts, %function
     .global exception_disable_interrupts
     mfc0 $t0, C0_STATUS
-    li $t1, ~(C0_SR_IE)
+    li $t1, ~(C0_SR_IM4 | C0_SR_IM3 | C0_SR_IE)
-    and $t0, $t0, $t1
+    and $t0, $t1
     mtc0 $t0, C0_STATUS
     jr $ra
 
@@ -195,7 +189,7 @@ exception_enable_watchdog:
     mtc0 $t1, C0_COMPARE
     mfc0 $t0, C0_STATUS
     li $t1, C0_SR_IM7
-    or $t0, $t0, $t1
+    or $t0, $t1
     mtc0 $t0, C0_STATUS
     jr $ra
 
@@ -206,7 +200,7 @@ exception_disable_watchdog:
     .global exception_disable_watchdog
     mfc0 $t0, C0_STATUS
     li $t1, ~(C0_SR_IM7)
-    and $t0, $t0, $t1
+    and $t0, $t1
     mtc0 $t0, C0_STATUS
     mtc0 $zero, C0_COMPARE
     jr $ra

sw/bootloader/src/exception.c

@@ -8,15 +8,6 @@
 #include "../assets/assets.h"
 
 
-#define EXCEPTION_INTERRUPT     (0)
-#define EXCEPTION_SYSCALL       (8)
-
-#define INTERRUPT_MASK_TIMER    (1 << 7)
-
-#define SYSCALL_CODE_MASK       (0x03FFFFC0UL)
-#define SYSCALL_CODE_BIT        (6)
-
-
 static const char *exception_get_description (uint8_t exception_code) {
     switch (exception_code) {
         case 0:  return "Interrupt";
@@ -41,48 +32,21 @@ static const char *exception_get_description (uint8_t exception_code) {
 }
 
 
-void exception_fatal_handler (uint32_t exception_code, uint32_t interrupt_mask, exception_t *e) {
+void exception_fatal_handler (uint32_t exception_code, exception_t *e) {
-    version_t *version = version_get();
-    uint32_t *instruction_address = (((uint32_t *) (e->epc.u32)) + ((e->cr & C0_CR_BD) ? 1 : 0));
-
     display_init((uint32_t *) (&assets_sc64_logo_640_240_dimmed));
 
-    display_printf("[ SC64 bootloader metadata ]\n");
+    version_print();
-    display_printf("branch: %s | tag: %s\n", version->git_branch, version->git_tag);
+    display_printf("[ Unhandled exception ]\n");
-    display_printf("sha: %s\n", version->git_sha);
+    display_printf("%s\n", exception_get_description(exception_code));
-    display_printf("msg: %s\n\n", version->git_message);
+    display_printf(" pc: 0x%08lX  sr: 0x%08lX  cr: 0x%08lX  va: 0x%08lX\n", e->epc.u32, e->sr, e->cr, e->badvaddr.u32);
-
+    display_printf(" zr: 0x%08lX  at: 0x%08lX  v0: 0x%08lX  v1: 0x%08lX\n", e->zr.u32, e->at.u32, e->v0.u32, e->v1.u32);
-    if (exception_code != EXCEPTION_SYSCALL) {
+    display_printf(" a0: 0x%08lX  a1: 0x%08lX  a2: 0x%08lX  a3: 0x%08lX\n", e->a0.u32, e->a1.u32, e->a2.u32, e->a3.u32);
-        display_printf("%s\n", exception_get_description(exception_code));
+    display_printf(" t0: 0x%08lX  t1: 0x%08lX  t2: 0x%08lX  t3: 0x%08lX\n", e->t0.u32, e->t1.u32, e->t2.u32, e->t3.u32);
-        display_printf(" pc: 0x%08lX  sr: 0x%08lX  cr: 0x%08lX  va: 0x%08lX\n", e->epc.u32, e->sr, e->cr, e->badvaddr.u32);
+    display_printf(" t4: 0x%08lX  t5: 0x%08lX  t6: 0x%08lX  t7: 0x%08lX\n", e->t4.u32, e->t5.u32, e->t6.u32, e->t7.u32);
-        display_printf(" zr: 0x%08lX  at: 0x%08lX  v0: 0x%08lX  v1: 0x%08lX\n", e->zr.u32, e->at.u32, e->v0.u32, e->v1.u32);
+    display_printf(" s0: 0x%08lX  s1: 0x%08lX  s2: 0x%08lX  s3: 0x%08lX\n", e->s0.u32, e->s1.u32, e->s2.u32, e->s3.u32);
-        display_printf(" a0: 0x%08lX  a1: 0x%08lX  a2: 0x%08lX  a3: 0x%08lX\n", e->a0.u32, e->a1.u32, e->a2.u32, e->a3.u32);
+    display_printf(" s4: 0x%08lX  s5: 0x%08lX  s6: 0x%08lX  s7: 0x%08lX\n", e->s4.u32, e->s5.u32, e->s6.u32, e->s7.u32);
-        display_printf(" t0: 0x%08lX  t1: 0x%08lX  t2: 0x%08lX  t3: 0x%08lX\n", e->t0.u32, e->t1.u32, e->t2.u32, e->t3.u32);
+    display_printf(" t8: 0x%08lX  t9: 0x%08lX  k0: 0x%08lX  k1: 0x%08lX\n", e->t8.u32, e->t9.u32, e->k0.u32, e->k1.u32);
-        display_printf(" t4: 0x%08lX  t5: 0x%08lX  t6: 0x%08lX  t7: 0x%08lX\n", e->t4.u32, e->t5.u32, e->t6.u32, e->t7.u32);
+    display_printf(" gp: 0x%08lX  sp: 0x%08lX  s8: 0x%08lX  ra: 0x%08lX\n\n", e->gp.u32, e->sp.u32, e->s8.u32, e->ra.u32);
-        display_printf(" s0: 0x%08lX  s1: 0x%08lX  s2: 0x%08lX  s3: 0x%08lX\n", e->s0.u32, e->s1.u32, e->s2.u32, e->s3.u32);
-        display_printf(" s4: 0x%08lX  s5: 0x%08lX  s6: 0x%08lX  s7: 0x%08lX\n", e->s4.u32, e->s5.u32, e->s6.u32, e->s7.u32);
-        display_printf(" t8: 0x%08lX  t9: 0x%08lX  k0: 0x%08lX  k1: 0x%08lX\n", e->t8.u32, e->t9.u32, e->k0.u32, e->k1.u32);
-        display_printf(" gp: 0x%08lX  sp: 0x%08lX  s8: 0x%08lX  ra: 0x%08lX\n\n", e->gp.u32, e->sp.u32, e->s8.u32, e->ra.u32);
-    } else {
-        display_printf("[ Runtime error ]\n");
-    }
-
-    if (exception_code == EXCEPTION_INTERRUPT) {
-        if (interrupt_mask & INTERRUPT_MASK_TIMER) {
-            exception_disable_watchdog();
-            display_printf("Still loading after 5 second limit...\n\n");
-            return;
-        }
-    } else if (exception_code == EXCEPTION_SYSCALL) {
-        uint32_t code = (((*instruction_address) & SYSCALL_CODE_MASK) >> SYSCALL_CODE_BIT);
-
-        if (code == TRIGGER_CODE_ERROR) {
-            const char *fmt = (const char *) (e->a0.u32);
-            va_list args = *((va_list *) (e->sp.u32));
-            display_vprintf(fmt, args);
-            display_printf("\n");
-        }
-    }
 
     while (1);
 }

sw/bootloader/src/exception.h

@@ -2,11 +2,6 @@
 #define EXCEPTION_H__
 
 
-#define TRIGGER_CODE_ERROR          (0)
-
-#define EXCEPTION_TRIGGER(code)     { asm volatile ("syscall %[c]\n" :: [c] "i" (code)); }
-
-
 void exception_enable_interrupts (void);
 void exception_disable_interrupts (void);
 void exception_enable_watchdog (void);

sw/bootloader/src/interrupt.c

@@ -1,6 +1,69 @@
-#include "exception_regs.h"
+#include "display.h"
+#include "sc64.h"
+#include "version.h"
+#include "../assets/assets.h"
 
 
-void exception_interrupt_handler (uint32_t exception_code, uint32_t interrupt_mask, exception_t *e) {
+typedef enum {
+    INTERRUPT_SW_0 = (1 << 0),
+    INTERRUPT_SW_1 = (1 << 1),
+    INTERRUPT_RCP = (1 << 2),
+    INTERRUPT_CART = (1 << 3),
+    INTERRUPT_PRENMI = (1 << 4),
+    INTERRUPT_HW_5 = (1 << 5),
+    INTERRUPT_HW_6 = (1 << 6),
+    INTERRUPT_TIMER = (1 << 7),
+} interrupt_t;
+
+
+static void exception_interrupt_unhandled (uint8_t interrupt) {
+    display_init((uint32_t *) (&assets_sc64_logo_640_240_dimmed));
+
+    version_print();
+    display_printf("[ Unhandled interrupt ]\n");
+    display_printf("Pending (0x%02X):\n", interrupt);
+    for (int i = 0; i < 8; i++) {
+        switch (interrupt & (1 << i)) {
+            case INTERRUPT_SW_0: display_printf(" Software interrupt (0)\n"); break;
+            case INTERRUPT_SW_1: display_printf(" Software interrupt (1)\n"); break;
+            case INTERRUPT_RCP: display_printf(" RCP interrupt (2)\n"); break;
+            case INTERRUPT_CART: display_printf(" CART interrupt (3)\n"); break;
+            case INTERRUPT_PRENMI: display_printf(" Pre NMI interrupt (4)\n"); break;
+            case INTERRUPT_HW_5: display_printf(" Hardware interrupt (5)\n"); break;
+            case INTERRUPT_HW_6: display_printf(" Hardware interrupt (6)\n"); break;
+            case INTERRUPT_TIMER: display_printf(" Timer interrupt (7)\n"); break;
+            default: break;
+        }
+    }
+
     while (1);
 }
+
+
+void exception_interrupt_handler (uint8_t interrupt) {
+    if (interrupt & INTERRUPT_CART) {
+        sc64_irq_t irq = sc64_irq_pending();
+
+        if (irq != SC64_IRQ_NONE) {
+            return sc64_irq_callback(irq);
+        }
+    }
+
+    if (interrupt & INTERRUPT_PRENMI) {
+        if (display_ready()) {
+            display_init(NULL);
+            display_printf("Resetting...\n");
+        }
+        while (1);
+    }
+
+    if (interrupt & INTERRUPT_TIMER) {
+        display_init((uint32_t *) (&assets_sc64_logo_640_240_dimmed));
+        version_print();
+        display_printf("[ Watchdog ]\n");
+        display_printf("SC64 bootloader did not finish loading in 5 seconds\n");
+        while (1);
+    }
+
+    exception_interrupt_unhandled(interrupt);
+}

sw/bootloader/src/sc64.c

@@ -1,5 +1,6 @@
 #include "io.h"
 #include "sc64.h"
+#include "error.h"
 
 
 typedef struct {
@@ -7,13 +8,16 @@ typedef struct {
     io32_t DATA[2];
     io32_t IDENTIFIER;
     io32_t KEY;
+    io32_t IRQ;
 } sc64_regs_t;
 
 #define SC64_REGS_BASE              (0x1FFF0000UL)
 #define SC64_REGS                   ((sc64_regs_t *) SC64_REGS_BASE)
 
 
-#define SC64_SR_IRQ_PENDING         (1 << 29)
+#define SC64_SR_CMD_IRQ_REQUEST     (1 << 8)
+#define SC64_SR_CMD_IRQ_PENDING     (1 << 28)
+#define SC64_SR_MCU_IRQ_PENDING     (1 << 29)
 #define SC64_SR_CMD_ERROR           (1 << 30)
 #define SC64_SR_CPU_BUSY            (1 << 31)
 
@@ -24,6 +28,9 @@ typedef struct {
 #define SC64_KEY_UNLOCK_2           (0x4F434B5FUL)
 #define SC64_KEY_LOCK               (0xFFFFFFFFUL)
 
+#define SC64_IRQ_CMD_CLEAR          (1 << 30)
+#define SC64_IRQ_MCU_CLEAR          (1 << 31)
+
 
 typedef enum {
     CMD_ID_IDENTIFIER_GET       = 'v',
@@ -67,16 +74,30 @@ typedef struct {
 } sc64_cmd_t;
 
 
+static bool use_cmd_irq = false;
+static volatile bool wait_cmd_irq = false;
+
+
 static sc64_error_t sc64_execute_cmd (sc64_cmd_t *cmd) {
+    uint32_t sr;
+
     pi_io_write(&SC64_REGS->DATA[0], cmd->arg[0]);
     pi_io_write(&SC64_REGS->DATA[1], cmd->arg[1]);
 
-    pi_io_write(&SC64_REGS->SR_CMD, (cmd->id & 0xFF));
+    if (use_cmd_irq) {
-
+        wait_cmd_irq = true;
-    uint32_t sr;
+        pi_io_write(&SC64_REGS->SR_CMD, (SC64_SR_CMD_IRQ_REQUEST | (cmd->id & 0xFF)));
-    do {
+        while (wait_cmd_irq);
         sr = pi_io_read(&SC64_REGS->SR_CMD);
-    } while (sr & SC64_SR_CPU_BUSY);
+        if (sr & SC64_SR_CPU_BUSY) {
+            error_display("[Unexpected] SC64 CMD busy flag set");
+        }
+    } else {
+        pi_io_write(&SC64_REGS->SR_CMD, (cmd->id & 0xFF));
+        do {
+            sr = pi_io_read(&SC64_REGS->SR_CMD);
+        } while (sr & SC64_SR_CPU_BUSY);
+    }
 
     if (sr & SC64_SR_CMD_ERROR) {
         return (sc64_error_t) (pi_io_read(&SC64_REGS->DATA[0]));
@@ -88,6 +109,18 @@ static sc64_error_t sc64_execute_cmd (sc64_cmd_t *cmd) {
     return SC64_OK;
 }
 
+static void sc64_mcu_irq_callback (void) {
+    error_display("[Unexpected] SC64 MCU interrupt received");
+}
+
+static void sc64_cmd_irq_callback (void) {
+    if (wait_cmd_irq) {
+        wait_cmd_irq = false;
+    } else {
+        error_display("[Unexpected] SC64 CMD interrupt received");
+    }
+}
+
 
 const char *sc64_error_description (sc64_error_t error) {
     sc64_error_type_t type = (sc64_error_type_t) ((error >> 24) & 0xFF);
@@ -164,12 +197,31 @@ bool sc64_check_presence (void) {
 }
 
 
-bool sc64_irq_pending (void) {
+void sc64_cmd_irq_enable (bool enable) {
-    return (pi_io_read(&SC64_REGS->SR_CMD) & SC64_SR_IRQ_PENDING);
+    use_cmd_irq = enable;
 }
 
-void sc64_irq_clear (void) {
+sc64_irq_t sc64_irq_pending (void) {
-    pi_io_write(&SC64_REGS->IDENTIFIER, 0);
+    uint32_t sr = pi_io_read(&SC64_REGS->SR_CMD);
+    sc64_irq_t irq = SC64_IRQ_NONE;
+    if (sr & SC64_SR_MCU_IRQ_PENDING) {
+        irq |= SC64_IRQ_MCU;
+    }
+    if (sr & SC64_SR_CMD_IRQ_PENDING) {
+        irq |= SC64_IRQ_CMD;
+    }
+    return irq;
+}
+
+void sc64_irq_callback (sc64_irq_t irq) {
+    if (irq & SC64_IRQ_MCU) {
+        sc64_mcu_irq_callback();
+        pi_io_write(&SC64_REGS->IRQ, SC64_IRQ_MCU_CLEAR);
+    }
+    if (irq & SC64_IRQ_CMD) {
+        sc64_cmd_irq_callback();
+        pi_io_write(&SC64_REGS->IRQ, SC64_IRQ_CMD_CLEAR);
+    }
 }
 
 

sw/bootloader/src/sc64.h

@@ -159,6 +159,12 @@ typedef enum {
     SD_CARD_STATUS_BYTE_SWAP = (1 << 4),
 } sc64_sd_card_status_t;
 
+typedef enum {
+    SC64_IRQ_NONE = 0,
+    SC64_IRQ_MCU = (1 << 0),
+    SC64_IRQ_CMD = (1 << 1),
+} sc64_irq_t;
+
 
 typedef struct {
     volatile uint8_t BUFFER[8192];
@@ -177,8 +183,9 @@ void sc64_unlock (void);
 void sc64_lock (void);
 bool sc64_check_presence (void);
 
-bool sc64_irq_pending (void);
+void sc64_cmd_irq_enable (bool enable);
-void sc64_irq_clear (void);
+sc64_irq_t sc64_irq_pending (void);
+void sc64_irq_callback (sc64_irq_t irq);
 
 sc64_error_t sc64_get_identifier (uint32_t *identifier);
 sc64_error_t sc64_get_version (uint16_t *major, uint16_t *minor, uint32_t *revision);

sw/bootloader/src/test.c

@@ -115,6 +115,22 @@ static void test_sc64_cfg (void) {
     display_printf("%02d:%02d:%02d", FROM_BCD(t.hour), FROM_BCD(t.minute), FROM_BCD(t.second));
     display_printf(" (%s)", weekdays[FROM_BCD(t.weekday)]);
     display_printf("\n");
+
+    int count = 65536;
+
+    for (int i = 0; i < count; i++) {
+        if ((i % (count / 64)) == 0) {
+            display_printf(".");
+        }
+        if ((error = sc64_get_identifier(&identifier)) != SC64_OK) {
+            error_display("Command IDENTIFIER_GET failed\n (%08X) - %s", error, sc64_error_description(error));
+        }
+        if (identifier != 0x53437632) {
+            error_display("Invalid identifier received: 0x%08X", identifier);
+        }
+    }
+
+    display_printf("\n");
 }
 
 static void test_pi (void) {
@@ -539,8 +555,18 @@ static struct {
 void test_execute (void) {
     sc64_error_t error;
 
+    const int test_count = sizeof(tests) / sizeof(tests[0]);
+    int current = 0;
+
+    display_init(NULL);
+    display_printf("SC64 Test suite (%d / %d)\n\n", 0, test_count);
+
+    display_printf("Initializing...\n");
+
     pi_io_config(0x0F, 0x05, 0x0C, 0x02);
 
+    sc64_cmd_irq_enable(true);
+
     if ((error = sc64_set_config(CFG_ID_ROM_WRITE_ENABLE, true)) != SC64_OK) {
         error_display("Command CONFIG_SET [ROM_WRITE_ENABLE] failed\n (%08X) - %s", error, sc64_error_description(error));
     }
@@ -551,9 +577,6 @@ void test_execute (void) {
 
     random_seed = __entropy + c0_count();
 
-    const int test_count = sizeof(tests) / sizeof(tests[0]);
-    int current = 0;
-
     while (true) {
         display_init(NULL);
         display_printf("SC64 Test suite (%d / %d)\n\n", current + 1, test_count);

sw/bootloader/src/version.c

@@ -1,7 +1,12 @@
-#include "version.h"
+#include "display.h"
 
 
-static version_t version = {
+const struct {
+    const char *git_branch;
+    const char *git_tag;
+    const char *git_sha;
+    const char *git_message;
+} version = {
 #ifdef GIT_BRANCH
     .git_branch = GIT_BRANCH,
 #else
@@ -29,6 +34,10 @@ static version_t version = {
 };
 
 
-version_t *version_get (void) {
+void version_print (void) {
-    return &version;
+    display_printf("[ SC64 bootloader metadata ]\n");
+    display_printf("branch: %s | tag: %s\n", version.git_branch, version.git_tag);
+    display_printf("sha: %s\n", version.git_sha);
+    display_printf("msg: %s\n", version.git_message);
+    display_printf("\n");
 }

sw/bootloader/src/version.h

@@ -2,15 +2,7 @@
 #define VERSION_H__
 
 
-typedef const struct {
+void version_print (void);
-    const char *git_branch;
-    const char *git_tag;
-    const char *git_sha;
-    const char *git_message;
-} version_t;
-
-
-const version_t *version_get (void);
 
 
 #endif