Kernel: Remove i686 support

Kernel/Prekernel/CMakeLists.txt

@@ -7,10 +7,7 @@ set(SOURCES
     ../../Userland/Libraries/LibELF/Relocation.cpp
     )
 
-
-if ("${SERENITY_ARCH}" STREQUAL "i686")
-    set(PREKERNEL_TARGET Prekernel32)
-elseif ("${SERENITY_ARCH}" STREQUAL "x86_64")
+if ("${SERENITY_ARCH}" STREQUAL "x86_64")
     set(PREKERNEL_TARGET Prekernel64)
 elseif("${SERENITY_ARCH}" STREQUAL "aarch64")
     message(SEND_ERROR "Prekernel is not needed on aarch64 and should not be compiled!")

Kernel/Prekernel/UBSanitizer.cpp

@@ -15,7 +15,7 @@ extern "C" {
 
 static void print_location(SourceLocation const&)
 {
-#if ARCH(I386) || ARCH(X86_64)
+#if ARCH(X86_64)
     asm volatile("cli; hlt");
 #else
     for (;;) { }

Kernel/Prekernel/boot.S

@@ -78,7 +78,6 @@ the page tables each contain 512 PTEs that map individual 4KB pages
 
 */
 
-#if ARCH(X86_64)
 gdt64:
     .quad 0
 gdt64code:
@@ -93,7 +92,6 @@ gdt64ptr:
 .global code64_sel
 code64_sel:
 .short code64_sel_value
-#endif
 
 start:
     jmp real_start
@@ -370,8 +368,6 @@ kernel_not_too_large:
     /* We should not return, but just in case, halt */
     hlt
 
-
-#if ARCH(X86_64)
 pae_supported:
     movl $0x80000001, %eax
     cpuid
@@ -393,15 +389,6 @@ long_mode_supported:
     popl %ebx
     popl %edx
     popl %eax
-#else
-/* If PAE is supported, continue with booting the system */
-
-pae_supported:
-    /* restore the pushed registers and continue with booting */
-    popl %ebx
-    popl %edx
-    popl %eax
-#endif
 
     /* We don't know where the bootloader might have put the command line.
      * It might be at an inconvenient location that we're not about to map,
@@ -416,7 +403,6 @@ pae_supported:
     movl $kernel_cmdline, %edi
     rep movsl
 
-#if ARCH(X86_64)
     /* clear pml4t */
     movl $boot_pml4t, %edi
     movl $1024, %ecx
@@ -428,7 +414,6 @@ pae_supported:
     movl $boot_pdpt, 0(%edi)
     /* R/W + Present */
     orl $0x3, 0(%edi)
-#endif
 
     /* clear pdpt */
     movl $boot_pdpt, %edi
@@ -438,11 +423,7 @@ pae_supported:
 
     /* set up pdpt[0] and pdpt[3] */
     movl $boot_pdpt, %edi
-#if ARCH(X86_64)
     movl $(boot_pd0 + 3), 0(%edi)
-#else
-    movl $(boot_pd0 + 1), 0(%edi)
-#endif
 
     /* clear pd0 */
     movl $boot_pd0, %edi
@@ -482,13 +463,8 @@ pae_supported:
     addl $4096, %eax
     loop 1b
 
-#if ARCH(X86_64)
     /* point CR3 to PML4T */
     movl $boot_pml4t, %eax
-#else
-    /* point CR3 to PDPT */
-    movl $boot_pdpt, %eax
-#endif
 
     movl %eax, %cr3
 
@@ -497,14 +473,12 @@ pae_supported:
     orl $0x60, %eax
     movl %eax, %cr4
 
-#if ARCH(X86_64)
 1:
     /* Enter Long-mode! ref(https://wiki.osdev.org/Setting_Up_Long_Mode)*/
     mov $0xC0000080, %ecx           /* Set the C-register to 0xC0000080, which is the EFER MSR.*/
     rdmsr                           /* Read from the model-specific register.*/
     or $(1 << 8), %eax              /* Set the LM-bit which is the 9th bit (bit 8).*/
     wrmsr                           /* Write to the model-specific register.*/
-#endif
 
     /* enable PG */
     movl %cr0, %eax
@@ -515,7 +489,6 @@ pae_supported:
     mov $stack_top, %esp
     and $-16, %esp
 
-#if ARCH(X86_64)
     /* Now we are in 32-bit compatibility mode, We still need to load a 64-bit GDT */
     mov $gdt64ptr, %eax
     lgdt (%eax)
@@ -532,9 +505,6 @@ pae_supported:
     mov %ax, %es
     mov %ax, %fs
     mov %ax, %gs
-#else
-    movl %ebx, multiboot_info_ptr
-#endif
 
     call reload_cr3
     call init
@@ -545,17 +515,10 @@ loop:
     jmp loop
 
 reload_cr3:
-#if ARCH(X86_64)
     pushq %rax
     mov %cr3, %rax
     mov %rax, %cr3
     popq %rax
-#else
-    pushl %eax
-    movl %cr3, %eax
-    movl %eax, %cr3
-    popl %eax
-#endif
     ret
 
 

Kernel/Prekernel/init.cpp

@@ -14,7 +14,7 @@
 #include <LibC/elf.h>
 #include <LibELF/Relocation.h>
 
-#if ARCH(I386) || ARCH(X86_64)
+#if ARCH(X86_64)
 #    include <Kernel/Arch/x86/ASM_wrapper.h>
 #    include <Kernel/Arch/x86/CPUID.h>
 #endif
@@ -90,11 +90,7 @@ extern "C" [[noreturn]] void init()
     __builtin_memcpy(kernel_program_headers, kernel_image + kernel_elf_header.e_phoff, sizeof(ElfW(Phdr)) * kernel_elf_header.e_phnum);
 
     FlatPtr kernel_physical_base = 0x200000;
-#if ARCH(I386)
-    FlatPtr default_kernel_load_base = 0xc0200000;
-#else
     FlatPtr default_kernel_load_base = 0x2000200000;
-#endif
 
     FlatPtr kernel_load_base = default_kernel_load_base;
 
@@ -125,11 +121,8 @@ extern "C" [[noreturn]] void init()
     VERIFY(kernel_load_base % 0x1000 == 0);
     VERIFY(kernel_load_base >= kernel_mapping_base + 0x200000);
 
-#if ARCH(I386)
-    int pdpt_flags = 0x1;
-#else
     int pdpt_flags = 0x3;
-#endif
+
     boot_pdpt[(kernel_mapping_base >> 30) & 0x1ffu] = (FlatPtr)boot_pd_kernel | pdpt_flags;
 
     boot_pd_kernel[0] = (FlatPtr)boot_pd_kernel_pt0 | 0x3;
@@ -213,13 +206,8 @@ extern "C" [[noreturn]] void init()
     }
 
     asm(
-#if ARCH(I386)
-        "add %0, %%esp"
-#else
         "mov %0, %%rax\n"
-        "add %%rax, %%rsp"
-#endif
-        ::"g"(kernel_mapping_base)
+        "add %%rax, %%rsp" ::"g"(kernel_mapping_base)
         : "ax");
 
     // unmap the 0-1MB region
@@ -244,7 +232,7 @@ u64 generate_secure_seed()
 {
     u32 seed = 0xFEEBDAED;
 
-#if ARCH(I386) || ARCH(X86_64)
+#if ARCH(X86_64)
     CPUID processor_info(0x1);
     if (processor_info.edx() & (1 << 4)) // TSC
         seed ^= read_tsc();