Enable and configure APLIC & IMSIC

4 files changed, 164 insertions, 3 deletions

diff --git a/kernel/aplic.c b/kernel/aplic.c
index 3b0a2f5..61a42c3 100644
--- a/kernel/aplic.c
+++ b/kernel/aplic.c
@@ -1,2 +1,121 @@
 #include "kernel/aplic.h"

 #include "kernel/spinlock.h"

+

+static volatile char* APLIC_M = (volatile char*)0x0c00'0000;

+static volatile char* APLIC_S = (volatile char*)0x0d00'0000;

+

+static volatile char* IMSIC_M = (volatile char*)0x2400'0000;

+static volatile char* IMSIC_S = (volatile char*)0x2800'0000;

+

+

+static inline uint32_t read(volatile char* base, uint32_t offset)

+{

+    return *(volatile uint32_t*)(base + offset);

+}

+

+static inline void write(volatile char* base, uint32_t offset, uint32_t v)

+{

+    *(volatile uint32_t*)(base + offset) = v;

+}

+

+enum

+{

+    DOMAINCFG_BASE      = 0x8000'0000,

+    DOMAINCFG_DM        = 0x0000'0004,

+    DOMAINCFG_DM_MSI    = 0x0000'0004,

+    DOMAINCFG_IE        = 0x0000'0100,

+};

+

+bool aplic_w_domaincfg(volatile char* base, uint32_t value)

+{

+    write(base, 0, value);

+    return (read(base, 0) & DOMAINCFG_DM) == (value & DOMAINCFG_DM);

+}

+

+void aplic_w_sourcecfg(volatile char* base, uint32_t source, uint32_t v)

+{

+    write(base, 4 + 4 * (source - 1), v);

+}

+

+void aplic_w_sourcecfg_delegate(volatile char* base, uint32_t source, uint32_t child)

+{

+    aplic_w_sourcecfg(base, source, (1U << 10) | (child & 0x3ff));

+}

+

+void aplic_w_sourcecfg_active_high(volatile char* base, uint32_t source)

+{

+    aplic_w_sourcecfg(base, source, 6);

+}

+

+void aplic_w_smsiaddr(volatile char* base, void* addr)

+{

+    write(base, 0x1BC8, (uint32_t)addr >> 12);

+    write(base, 0x1BCC, 0);

+}

+

+void aplic_enable_intr(volatile char* base, uint32_t source)

+{

+    write(base, 0x1EDC, source);

+}

+

+void aplic_w_target_msi(volatile char* base, uint32_t source, uint32_t hart_index, uint32_t guest_index, uint32_t eiid)

+{

+    uint32_t v = ((hart_index & 0x3fff) << 18) | ((guest_index & 0x3f) << 12) | (eiid & 0x3ff);

+    write(base, 0x3000 + 4 * source, v);

+}

+

+enum

+{

+    EIDELIVERY  = 0x70,

+    EITHRESHOLD = 0x72,

+    EIE0        = 0xC0,

+};

+

+enum

+{

+    EIDELIVERY_DISABLED = 0,

+    EIDELIVERY_ENABLED  = 1,

+};

+

+void imsic_w_seidelivery(uint32_t v)

+{

+    __asm__ volatile(

+        "csrw siselect, %0;"

+        "csrw sireg, %1;"

+        :: "r"(EIDELIVERY), "r"(v));

+}

+

+void imsic_w_seithreshold(uint32_t v)

+{

+    __asm__ volatile(

+        "csrw siselect, %0;"

+        "csrw sireg, %1;"

+        :: "r"(EITHRESHOLD), "r"(v));

+}

+

+void imsic_s_seie(uint32_t id)

+{

+    __asm__ volatile(

+        "csrw siselect, %0;"

+        "csrs sireg, %1;"

+        :: "r"(EIE0 + id / 32), "r"(1U << (id % 32)));

+}

+

+void aplic_init()

+{

+    uint32_t domaincfg = DOMAINCFG_BASE | DOMAINCFG_DM_MSI | DOMAINCFG_IE;

+    if (!aplic_w_domaincfg(APLIC_M, domaincfg)) panic("aplic_init: enable APLIC M");

+    if (!aplic_w_domaincfg(APLIC_S, domaincfg)) panic("aplic_init: enable APLIC S");

+    

+    aplic_w_smsiaddr(APLIC_M, (void*)IMSIC_S);

+

+    uint32_t uart_source = 10;

+    aplic_w_sourcecfg_delegate(APLIC_M, uart_source, 0);

+    aplic_w_sourcecfg_active_high(APLIC_S, uart_source);

+    aplic_w_target_msi(APLIC_S, uart_source, 0, 0, uart_source);

+    aplic_enable_intr(APLIC_S, uart_source);

+

+    imsic_w_seithreshold(0);

+    imsic_w_seidelivery(EIDELIVERY_ENABLED);

+    imsic_s_seie(uart_source);

+}

diff --git a/kernel/aplic.h b/kernel/aplic.h
index a3b5ccb..b96363d 100644
--- a/kernel/aplic.h
+++ b/kernel/aplic.h
@@ -2,4 +2,5 @@
 

 #include "kernel/lib.h"

 

+void aplic_init();

 

diff --git a/kernel/start.c b/kernel/start.c
index b7170ae..859ae5d 100644
--- a/kernel/start.c
+++ b/kernel/start.c
@@ -3,6 +3,7 @@
 #include "kernel/kalloc.h"

 #include "kernel/vm.h"

 #include "kernel/cpu.h"

+#include "kernel/aplic.h"

 

 Cpu cpus[MAX_CPU];

 

@@ -12,13 +13,51 @@ extern uint32_t _ram_end;
 

 void kstrap()

 {

-    panic("kstrap");

+    uint32_t scause;

+    __asm__ volatile("csrr %0, scause" : "=r"(scause));

+    switch (scause)

+    {

+        case 0: panic("kstrap: Instruction address misaligned");

+        case 1: panic("kstrap: Instruction access fault");

+        case 2: panic("kstrap: Illegal instruction");

+        case 3: panic("kstrap: Breakpoint");

+        case 4: panic("kstrap: Load address misaligned");

+        case 5: panic("kstrap: Load access fault");

+        case 6: panic("kstrap: Store/AMO address misaligned");

+        case 7: panic("kstrap: Store/AMO access fault");

+        case 8: panic("kstrap: Environment call from U-mode");

+        case 9: panic("kstrap: Environment call from S-mode");

+        case 12: panic("kstrap: Instruction page fault");

+        case 13: panic("kstrap: Load page fault");

+        case 14: panic("kstrap: Reserved");

+        case 15: panic("kstrap: Store/AMO page fault");

+        case 18: panic("kstrap: Software check");

+        case 19: panic("kstrap: Hardware error");

+        default: panic("kstrap: Unknown");

+    }

+}

+

+void uart_init()

+{

+    volatile char* UART_BASE = (volatile char*)0x1000'0000;

+    

+    // Set LCR[1:0] to 0b11 for 8-bit words

+    *(UART_BASE + 3) = 0b0000'0011;

+

+    // Set FCR[0] to 1 to enable FIFO

+    *(UART_BASE + 2) = 0b0000'0001;

+

+    // Set IER[0] to 1 to enable interrupts on receive

+    *(UART_BASE + 1) = 0b0000'0001;

 }

 

 void kstart()

 {

+    uart_init();

+    

     kalloc_init();

     kvm_init();

+    aplic_init();

    

     panic("kstart: end");

 }

diff --git a/kernel/vm.c b/kernel/vm.c
index c1adbe7..8ca6666 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -100,8 +100,10 @@ void kvm_init()
     kvm_map(&_stack_start, &_stack_start, &_stack_end - &_stack_start, VM_RW);

     

     kvm_map((void*)0x1000'0000, (void*)0x1000'0000, PAGE_SIZE, VM_RW); // UART

-    kvm_map((void*)0x0c00'0000, (void*)0x0c00'0000, 0x8000, VM_RW); // APLIC-M

-    kvm_map((void*)0x0d00'0000, (void*)0x0d00'0000, 0x8000, VM_RW); // APLIC-S

+    kvm_map((void*)0x0c00'0000, (void*)0x0c00'0000, 0x8000, VM_RW); // APLIC M

+    kvm_map((void*)0x0d00'0000, (void*)0x0d00'0000, 0x8000, VM_RW); // APLIC S

+    kvm_map((void*)0x2400'0000, (void*)0x2400'0000, 0x1000, VM_RW); // IMSIC M

+    kvm_map((void*)0x2800'0000, (void*)0x2800'0000, 0x1000, VM_RW); // IMSIC S

 

     w_satp(SATP_MODE_SV32 | ((uint32_t)kroot >> 12));

     sfence_vma();