pci support

Makefile

@@ -1,4 +1,4 @@
-CC = /home/rami/crossdev/bin/i686-elf-gcc
+CC = i686-elf-gcc
 AS = nasm
 
 BUILDDIR := build
@@ -19,7 +19,7 @@ ISO := Hazel.iso
 
 CFLAGS    := -ffreestanding -Wall -Wextra -Werror -I $(INCLUDEDIR) -I lib
 LDFLAGS   := -ffreestanding -nostdlib -lgcc -T kernel/kernel.ld
-QEMUFLAGS := -d int -cdrom $(BUILDDIR)/$(ISO) -s -m 512M -serial stdio
+QEMUFLAGS := -cdrom $(BUILDDIR)/$(ISO) -s -m 512M -serial stdio
 
 $(BUILDDIR)/$(KIMG): $(KOBJ) $(LOBJ)
 	$(CC) $^ -o $@ $(LDFLAGS)

include/kernel/acpi.h

@@ -44,7 +44,7 @@ struct GenericAddressStructure
     uint64_t Address;
 };
 
-struct fadt {
+typedef struct {
     sdt_hdr_t hdr;
     uint32_t FirmwareCtrl;
     uint32_t Dsdt;
@@ -109,10 +109,10 @@ struct fadt {
     struct GenericAddressStructure X_PMTimerBlock;
     struct GenericAddressStructure X_GPE0Block;
     struct GenericAddressStructure X_GPE1Block;
-};
+} fadt_t;
 
 rsdp_t *acpi_find_rsdp();
-uint32_t acpi_checksum(void *s, int size);
+uint8_t acpi_checksum(void *s, int size);
-void *acpi_find_sdt(rsdt_t *rsdt, const char sig[6]);
+void *acpi_find_sdt(rsdt_t *rsdt, const char *sig);
 
 #endif

include/kernel/io.h

@@ -6,4 +6,10 @@
 uint8_t inb(uint16_t port);
 void outb(uint16_t port, uint8_t byte);
 
+uint16_t inw(uint16_t port);
+void outw(uint16_t port, uint16_t byte);
+
+uint32_t inl(uint16_t port);
+void outl(uint16_t port, uint32_t byte);
+
 #endif

include/kernel/pci.h

@@ -0,0 +1,11 @@
+#ifndef HAZEL_PCI_H_
+#define HAZEL_PCI_H_
+
+#include <stdint.h>
+
+#define PCI_CONFIG_ADDR 0xCF8
+#define PCI_CONFIG_DATA 0xCFC
+
+uint16_t pci_read_cfg(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
+
+#endif

kernel/acpi.c

@@ -16,24 +16,24 @@ rsdp_t *acpi_find_rsdp() {
     return 0;
 }
 
-uint32_t acpi_checksum(void *s, int size) {
+uint8_t acpi_checksum(void *s, int size) {
     uint32_t sum = 0;
     for (int i = 0; i < size; i++) {
         sum += ((uint8_t *)s)[i];
     }
 
-    return sum;
+    return (sum & 0xFF) == 0;
 }
 
-void *acpi_find_sdt(rsdt_t *rsdt, const char sig[6]) {
+void *acpi_find_sdt(rsdt_t *rsdt, const char *sig) {
     int entries = (rsdt->hdr.Length - sizeof(sdt_hdr_t)) / 4;
     for (int i = 0; i < entries; i++) {
         const char *ptr = (const char *)rsdt->other_tables[i];
         int j = 0;
-        for (; j < RSDP_SIG_LEN; j++)
+        for (; j < 4; j++)
             if (ptr[j] != sig[j]) break;
 
-        if (j == RSDP_SIG_LEN) return (void *)ptr;
+        if (j == 4) return (void *)ptr;
     }
     
     return 0;

kernel/io.c

@@ -15,3 +15,35 @@ void outb(uint16_t port, uint8_t byte) {
             : // no output
             : "a" (byte), "d" (port));
 }
+
+uint16_t inw(uint16_t port) {
+    uint16_t result;
+
+    asm volatile ("in %%dx, %%ax"
+            : "=a" (result)
+            : "d"  (port));
+
+    return result;
+}
+
+void outw(uint16_t port, uint16_t byte) {
+    asm volatile ("out %%ax, %%dx"
+            : // no output
+            : "a" (byte), "d" (port));
+}
+
+uint32_t inl(uint16_t port) {
+    uint32_t result;
+
+    asm volatile ("in %%dx, %%eax"
+            : "=a" (result)
+            : "d"  (port));
+
+    return result;
+}
+
+void outl(uint16_t port, uint32_t byte) {
+    asm volatile ("out %%eax, %%dx"
+            : // no output
+            : "a" (byte), "d" (port));
+}

kernel/kernel.c

@@ -9,6 +9,7 @@
 #include <kernel/task.h>
 #include <kernel/ps2.h>
 #include <kernel/acpi.h>
+#include <kernel/pci.h>
 #include <stdint.h>
 
 kernel_ctx_t ctx = {0};
@@ -126,16 +127,33 @@ void kernel(multiboot_info_t *info) {
 
     rsdp_t *rsdp = acpi_find_rsdp();
     if (!rsdp) goto halt;
-    if ((acpi_checksum(rsdp, sizeof(rsdp_t)) & 0xFF) != 0) goto halt;
+    if (!acpi_checksum(rsdp, sizeof(rsdp_t))) goto halt;
-    LOG("RSDP found\n");
+
+    if (rsdp->Revision == 0) LOG("Using ACPI version 1.0\n")
+    else if (rsdp->Revision == 2) {
+        LOG("ACPI versions higher than 1.0 are not currently supported!\n");
+        goto halt;
+    }
 
     rsdt_t *rsdt = (rsdt_t *)(rsdp->RsdtAddress);
     if (!rsdt) goto halt;
-    LOG("%08X\n", acpi_checksum(rsdt, rsdt->hdr.Length));
+    if (!acpi_checksum(rsdt, rsdt->hdr.Length)) goto halt;
-    if (acpi_checksum(rsdt, sizeof(rsdt_t)) != 0) goto halt;
     LOG("RSDT is valid\n");
 
-//    for (;;) {}
+    void *mcfg = acpi_find_sdt(rsdt, "MCFG");
+    if (!mcfg) LOG("PCIe not supported\n");
+
+    for (int i = 0; i < 256; i++) {
+        for (int j = 0; j < 32; j++) {
+            for (int k = 0; k < 8; k++) {
+                uint16_t w = pci_read_cfg(i, j, k, 0xA);
+                uint8_t class = (uint8_t)(w >> 8);
+                uint8_t subclass = (uint8_t)w;
+                if (class == 0xFF) continue;
+                LOG("Class: %04X | Subclass: %04X\n", class, subclass);
+            }
+        }
+    }
 
     pic_remap(PIC_1_START, PIC_2_START);
     ps2_init();

kernel/pci.c

@@ -0,0 +1,19 @@
+#include <kernel/pci.h>
+#include <kernel/io.h>
+
+uint16_t pci_read_cfg(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset) {
+    uint32_t address;
+    uint32_t lbus  = (uint32_t)bus;
+    uint32_t lslot = (uint32_t)slot;
+    uint32_t lfunc = (uint32_t)func;
+    uint16_t tmp = 0;
+
+    // Create configuration address as per Figure 1
+    address = (uint32_t)((lbus << 16) | (lslot << 11) |
+            (lfunc << 8) | (offset & 0xFC) | ((uint32_t)0x80000000));
+
+    outl(PCI_CONFIG_ADDR, address);
+
+    tmp = (uint16_t)((inl(PCI_CONFIG_DATA) >> ((offset & 2) * 8)) & 0xFFFF);
+    return tmp;
+}