Map structures

include/kernel/infrastructure/acpi/acpi.h

@@ -38,6 +38,8 @@
 #include <stdbool.h>
 #include <stddef.h>
 
+bool verify_acpi_checksum(const void *buffer, size_t buflen);
+
 bool verify_acpi_rsdp(const acpi_rsdp_t *rsdp);
 
 void map_acpi_tables(kern_paddr_t rsdp_paddr, const acpi_table_def_t *table_defs);

include/kernel/infrastructure/acpi/tables.h

@@ -150,7 +150,7 @@ typedef PACKED_STRUCT {
     acpi_table_header_t header;
     uint32_t            local_intr_controller_addr;
     uint32_t            flags;
-    char                entries[];
+    const char          entries[];
 } acpi_madt_t;
 
 typedef PACKED_STRUCT {

include/kernel/infrastructure/i686/firmware/asm/bios.h

@@ -34,4 +34,6 @@
 
 #define BIOS_BDA_EBDA_SEGMENT   0x40e
 
+#define BIOS_BDA_MEMORY_SIZE    0x413
+
 #endif

include/kernel/infrastructure/i686/firmware/asm/mp.h

@@ -50,6 +50,10 @@
 
 #define MP_CONF_TABLE_SIGNATURE     "PCMP"
 
+#define MP_REVISION_V1_1            1
+
+#define MP_REVISION_V1_4            4
+
 /* Multiprocessor Specification 1.4 Table 4-3 Base MP Configuration Table Entry
  * Types */
 

include/kernel/infrastructure/i686/firmware/bios.h

@@ -33,8 +33,11 @@
 #define JINUE_KERNEL_INFRASTRUCTURE_I686_FIRMWARE_BIOS_H
 
 #include <kernel/infrastructure/i686/firmware/asm/bios.h>
+#include <stddef.h>
 #include <stdint.h>
 
-uintptr_t get_bios_ebda_addr(void);
+uint32_t get_bios_ebda_addr(void);
+
+size_t get_bios_base_memory_size(void);
 
 #endif

include/kernel/infrastructure/i686/firmware/mp.h

@@ -32,6 +32,7 @@
 #ifndef JINUE_KERNEL_INFRASTRUCTURE_I686_FIRMWARE_MP_H
 #define JINUE_KERNEL_INFRASTRUCTURE_I686_FIRMWARE_MP_H
 
+#include <kernel/infrastructure/i686/firmware/asm/mp.h>
 #include <stdint.h>
 
 /* Multiprocessor Specification 1.4 section 4.1 MP Floating Pointer
@@ -46,7 +47,7 @@ typedef struct {
     uint8_t     feature1;
     uint8_t     feature2;
     uint8_t     feature_reserved[3];
-} mp_floating_ptr_t;
+} mp_ptr_struct_t;
 
 /* Multiprocessor Specification 1.4 section 4.2 MP Configuration Table
  * Header */
@@ -65,7 +66,7 @@ typedef struct {
     uint16_t    ext_table_length;
     uint8_t     ext_table_checksum;
     uint8_t     reserved;
-    char        entries[];    
+    const char  entries[];
 } mp_conf_table_t;
 
 /* Multiprocessor Specification 1.4 section 4.3.1 Processor Entries */
@@ -112,4 +113,8 @@ typedef struct {
     uint8_t     dest_apic_intn;
 } mp_entry_intr_t;
 
+void find_mp(void);
+
+void init_mp(void);
+
 #endif

kernel/Makefile

@@ -108,6 +108,7 @@ sources.kernel.c = \
 	infrastructure/i686/drivers/vga.c \
 	infrastructure/i686/firmware/acpi.c \
 	infrastructure/i686/firmware/bios.c \
+	infrastructure/i686/firmware/mp.c \
 	infrastructure/i686/pmap/nopae.c \
 	infrastructure/i686/pmap/pmap.c \
 	infrastructure/i686/pmap/pae.c \

kernel/infrastructure/acpi/acpi.c

@@ -37,13 +37,17 @@
 #include <string.h>
 
 /**
- * Verify the checksum of an ACPI data structure
+ * Verify the checksum of an ACPI data structure (RSDP, RSDT, ACPI table)
+ * 
+ * On x86, this function is also used to verify the checksum of the floating
+ * pointer structure and MP configuration table header from Intel's
+ * Multiprocessor Specification since the checksum algorithm is the same.
  *
- * @param buffer pointer to ACPI data structure
+ * @param buffer pointer to ACPI (or MP) data structure
  * @param buflen size of ACPI data structure
  * @return true for correct checksum, false for checksum mismatch
  */
-static bool verify_checksum(const void *buffer, size_t buflen) {
+bool verify_acpi_checksum(const void *buffer, size_t buflen) {
     uint8_t sum = 0;
 
     for(int idx = 0; idx < buflen; ++idx) {
@@ -64,7 +68,7 @@ bool verify_acpi_rsdp(const acpi_rsdp_t *rsdp) {
         return false;
     }
 
-    if(!verify_checksum(rsdp, ACPI_V1_RSDP_SIZE)) {
+    if(!verify_acpi_checksum(rsdp, ACPI_V1_RSDP_SIZE)) {
         return false;
     }
 
@@ -76,7 +80,7 @@ bool verify_acpi_rsdp(const acpi_rsdp_t *rsdp) {
         return false;
     }
 
-    return verify_checksum(rsdp, sizeof(acpi_rsdp_t));
+    return verify_acpi_checksum(rsdp, sizeof(acpi_rsdp_t));
 }
 
 /**
@@ -123,7 +127,7 @@ static const void *map_table(const acpi_table_header_t *header) {
 
     resize_map_in_kernel(header->length);
 
-    if(! verify_checksum(header, header->length)) {
+    if(! verify_acpi_checksum(header, header->length)) {
         return NULL;
     }
 

kernel/infrastructure/i686/firmware/acpi.c

@@ -35,6 +35,7 @@
 #include <kernel/infrastructure/i686/firmware/acpi.h>
 #include <kernel/infrastructure/i686/firmware/bios.h>
 #include <kernel/infrastructure/i686/types.h>
+#include <kernel/utils/asm/utils.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
@@ -79,14 +80,14 @@ static const acpi_rsdp_t *find_rsdp(void) {
     }
 
     /* TODO define some PC address map somewhere, use in VGA driver as well */
-    const char *top     = (const char *)(0xa0000 - 1024);
+    const char *top     = (const char *)(0xa0000 - KB);
     const char *ebda    = (const char *)get_bios_ebda_addr();
 
     if(ebda == NULL || ebda > top) {
         return NULL;
     }
 
-    for(const char *addr = ebda; addr < ebda + 1024; addr += 16) {
+    for(const char *addr = ebda; addr < ebda + KB; addr += 16) {
         const acpi_rsdp_t *rsdp = (const acpi_rsdp_t *)addr;
 
         if(verify_acpi_rsdp(rsdp)) {

kernel/infrastructure/i686/firmware/bios.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2024-2025 Philippe Aubertin.
+ * Copyright (C) 2025 Philippe Aubertin.
  * All rights reserved.
 
  * Redistribution and use in source and binary forms, with or without
@@ -30,9 +30,11 @@
  */
 
 #include <kernel/infrastructure/i686/firmware/bios.h>
+#include <kernel/utils/asm/utils.h>
 #include <stdlib.h>
 
-uintptr_t get_bios_ebda_addr(void) {
+/* The return value must be aligned on 16 bytes. */
+uint32_t get_bios_ebda_addr(void) {
     uintptr_t ebda = 16 * (*(uint16_t *)BIOS_BDA_EBDA_SEGMENT);
 
     /* TODO define some PC address map somewhere, use in VGA driver as well */
@@ -42,3 +44,14 @@ uintptr_t get_bios_ebda_addr(void) {
 
     return ebda;
 }
+
+/* The return value must be aligned on 16 bytes */
+size_t get_bios_base_memory_size(void) {
+    size_t size_kb = *(uint16_t *)BIOS_BDA_MEMORY_SIZE;
+
+    if(size_kb < 512 || size_kb > 640) {
+        return 0;
+    }
+
+    return size_kb * KB;
+}