build: Remove dependency on GCC-specific -fplan9-extensions flag

stage23/Makefile

@@ -45,7 +45,6 @@ S2CFLAGS = -Os -g -pipe -Wall -Wextra $(WERROR)
 
 INTERNAL_CFLAGS := \
 	-std=gnu11 \
-	-fplan9-extensions \
 	-ffreestanding \
 	-fno-stack-protector \
 	-fno-omit-frame-pointer \

stage23/fs/iso9660.s2.c

@@ -43,7 +43,7 @@ struct iso9660_volume_descriptor {
 } __attribute__((packed));
 
 struct iso9660_primary_volume {
-    struct iso9660_volume_descriptor;
+    struct iso9660_volume_descriptor volume_descriptor;
 
     union {
         struct {

stage23/lib/acpi.c

@@ -128,7 +128,7 @@ void acpi_get_smbios(void **smbios32, void **smbios64) {
 void *acpi_get_table(const char *signature, int index) {
     int cnt = 0;
 
-    struct rsdp_rev2 *rsdp = acpi_get_rsdp();
+    struct rsdp *rsdp = acpi_get_rsdp();
     if (rsdp == NULL)
         return NULL;
 
@@ -143,7 +143,7 @@ void *acpi_get_table(const char *signature, int index) {
         rsdt = (struct rsdt *)(uintptr_t)rsdp->rsdt_addr;
 
     size_t entry_count =
-        (rsdt->length - sizeof(struct sdt)) / (use_xsdt ? 8 : 4);
+        (rsdt->header.length - sizeof(struct sdt)) / (use_xsdt ? 8 : 4);
 
     for (size_t i = 0; i < entry_count; i++) {
         struct sdt *ptr;

stage23/lib/acpi.h

@@ -24,10 +24,7 @@ struct rsdp {
     char     oem_id[6];
     uint8_t  rev;
     uint32_t rsdt_addr;
-} __attribute__((packed));
-
-struct rsdp_rev2 {
-    struct rsdp;
+    // Rev 2 only after this comment
     uint32_t length;
     uint64_t xsdt_addr;
     uint8_t  ext_checksum;
@@ -35,7 +32,7 @@ struct rsdp_rev2 {
 } __attribute__((packed));
 
 struct rsdt {
-    struct sdt;
+    struct sdt header;
     char ptrs_start[];
 } __attribute__((packed));
 

stage23/sys/lapic.c

@@ -7,7 +7,7 @@
 #include <lib/acpi.h>
 
 struct dmar {
-    struct sdt;
+    struct sdt header;
     uint8_t host_address_width;
     uint8_t flags;
     uint8_t reserved[10];

stage23/sys/smp.c

@@ -13,7 +13,7 @@
 #include <mm/pmm.h>
 
 struct madt {
-    struct sdt;
+    struct sdt header;
     uint32_t local_controller_addr;
     uint32_t flags;
     char     madt_entries_begin[];
@@ -25,14 +25,14 @@ struct madt_header {
 } __attribute__((packed));
 
 struct madt_lapic {
-    struct madt_header;
+    struct madt_header header;
     uint8_t  acpi_processor_uid;
     uint8_t  lapic_id;
     uint32_t flags;
 } __attribute__((packed));
 
 struct madt_x2apic {
-    struct madt_header;
+    struct madt_header header;
     uint8_t  reserved[2];
     uint32_t x2apic_id;
     uint32_t flags;
@@ -164,7 +164,7 @@ struct smp_information *init_smp(size_t    header_hack_size,
     size_t max_cpus = 0;
 
     for (uint8_t *madt_ptr = (uint8_t *)madt->madt_entries_begin;
-      (uintptr_t)madt_ptr < (uintptr_t)madt + madt->length;
+      (uintptr_t)madt_ptr < (uintptr_t)madt + madt->header.length;
       madt_ptr += *(madt_ptr + 1)) {
         switch (*madt_ptr) {
             case 0: {
@@ -200,7 +200,7 @@ struct smp_information *init_smp(size_t    header_hack_size,
 
     // Try to start all APs
     for (uint8_t *madt_ptr = (uint8_t *)madt->madt_entries_begin;
-      (uintptr_t)madt_ptr < (uintptr_t)madt + madt->length;
+      (uintptr_t)madt_ptr < (uintptr_t)madt + madt->header.length;
       madt_ptr += *(madt_ptr + 1)) {
         switch (*madt_ptr) {
             case 0: {