arm64: Get to userspace

Hacky, and still very flawed. But we got to userspace! Stable!

Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>

Makefile

@@ -146,9 +146,9 @@ qemu-riscv: fullbuild-plus-full-initrd
 	qemu-system-$(shell scripts/target-triplet-to-arch.sh $(HOST)) -kernel kernel/vmonyx -m 512M -machine virt \
 	-serial stdio -s -initrd initrd.tar -smp 4
 
-qemu-arm64: fullbuild-plus-initrd
+qemu-arm64: fullbuild-plus-full-initrd
 	qemu-system-$(shell scripts/target-triplet-to-arch.sh $(HOST)) -kernel kernel/vmonyx -m 512M -machine virt \
-	-monitor stdio -cpu cortex-a53 -d int -s -no-shutdown -no-reboot -initrd initrd.tar
+	-monitor stdio -cpu cortex-a53 -s -no-shutdown -no-reboot -initrd initrd.tar
 
 qemu: iso
 	qemu-system-$(shell scripts/target-triplet-to-arch.sh $(HOST)) \

kernel/arch/arm64/Makefile

@@ -1,4 +1,6 @@
-arm64-y:= image.o fpu.o copy_user.o stubs.o vdso_helper.o mmu.o early_mmu.o virt-uart.o entry.o traps.o interrupts.o
+arm64-y:= image.o fpu.o copy_user.o stubs.o vdso_helper.o mmu.o early_mmu.o virt-uart.o \
+entry.o traps.o interrupts.o irq.o syscall.o usercopy.o scheduler.o timer.o gic.o \
+process.o panic.o
 
 obj-y+= $(patsubst %, arch/arm64/%, $(arm64-y))
 

kernel/arch/arm64/copy_user.S

@@ -1,27 +1,104 @@
 /*
-* Copyright (c) 2022 Pedro Falcato
-* This file is part of Onyx, and is released under the terms of the MIT License
-* check LICENSE at the root directory for more information
-*/
-
-/* TODO: Stubs */
-.global copy_to_user
-.global copy_from_user
-.global user_memset
-.global get_user64
-.global get_user32
-.global strlen_user
-.type get_user64, @function
-.type copy_to_user,@function
-.type copy_from_user,@function
-.type strlen_user,@function
-.type user_memset,@function
-.type get_user32,@function
-copy_from_user:
-strlen_user:
-get_user64:
-get_user32:
-user_memset:
-copy_to_user:
+ * Copyright (c) 2023 Pedro Falcato
+ * This file is part of Onyx, and is released under the terms of the MIT License
+ * check LICENSE at the root directory for more information
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/* ssize_t copy_to_user_internal(void *user, const void *data, size_t size); */
+.global copy_to_user_internal
+.type copy_to_user_internal,@function
+copy_to_user_internal:
+    mov x3, x0
+    mov x0, xzr
+    /* x2 = limit, x3 = user, x1 = data, x0 = 0 */
+    cbz x2, 3f
+    add x2, x3, x2
+1:
+    ldrb w4, [x1], #1
+2:
+    strb w4, [x3], #1
+    cmp x2, x3
+    bne 1b
+3:
+    ret
+4:
+    mov x0, -14
+    ret
+
+.pushsection .ehtable
+    .dword 2b
+    .dword 4b
+.popsection
+
+
+/* ssize_t copy_from_user_internal(void *data, const void *usr, size_t size); */
+.global copy_from_user_internal
+.type copy_from_user_internal,@function
+copy_from_user_internal:
+    mov x3, x0
+    mov x0, xzr
+    /* x2 = limit, x3 = user, x1 = data, x0 = 0 */
+    cbz x2, 3f
+    add x2, x3, x2
+1:
+    ldrb w4, [x1], #1
+    strb w4, [x3], #1
+    cmp x2, x3
+    bne 1b
+3:
+    ret
+4:
+    mov x0, -14
+    ret
+
+.pushsection .ehtable
+    .dword 1b
+    .dword 4b
+.popsection
+
+/* ssize_t user_memset_internal(void *data, int val, size_t len); */
+.global user_memset_internal
+.type user_memset_internal,@function
+user_memset_internal:
+    and w1, w1, 0xff
+    cbz x2, 3f
+    add x2, x0, x2
+1:
+    strb w1, [x0], #1
+    cmp x2, x0
+    bne 1b
+3:
+    mov x0, xzr
+    ret
+4:
     mov x0, -14
     ret
+
+.pushsection .ehtable
+    .dword 1b
+    .dword 4b
+.popsection
+
+/* ssize_t strlen_user_internal(const char *user); */
+.global strlen_user_internal
+.type strlen_user_internal,@function
+strlen_user_internal:
+    mov x1, x0
+    mov x0, xzr
+1:
+    ldrb w2, [x1], #1
+    cbz w2, 2f
+    add x0, x0, 1
+    b 1b
+2:
+    ret 
+4:
+    mov x0, -14
+    ret
+
+.pushsection .ehtable
+    .dword 1b
+    .dword 4b
+.popsection

kernel/arch/arm64/entry.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Pedro Falcato
+ * Copyright (c) 2022 - 2023 Pedro Falcato
  * This file is part of Onyx, and is released under the terms of the MIT License
  * check LICENSE at the root directory for more information
  *
@@ -23,9 +23,8 @@
 extern char percpu_base;
 
 void time_init();
-void riscv_cpu_init();
-void plic_init();
 void arm64_setup_trap_handling();
+void arm64_timer_init();
 
 extern "C" void kernel_entry(void *fdt)
 {
@@ -42,7 +41,6 @@ extern "C" void kernel_entry(void *fdt)
     vm_update_addresses(arch_high_half);
 
     paging_protect_kernel();
-    platform_serial_write("Done MMU protection\n", sizeof("Done MMU protection\n"));
 
     vm_late_init();
 
@@ -53,4 +51,14 @@ extern "C" void kernel_entry(void *fdt)
     console_init();
 
     device_tree::enumerate();
+
+    smp::set_number_of_cpus(1);
+    smp::set_online(0);
 }
+
+void init_arch_vdso()
+{
+    vdso_init();
+}
+
+INIT_LEVEL_EARLY_CORE_KERNEL_ENTRY(init_arch_vdso);

kernel/arch/arm64/fpu.cpp

@@ -1,32 +1,127 @@
 /*
- * Copyright (c) 2022 Pedro Falcato
+ * Copyright (c) 2022 - 2023 Pedro Falcato
  * This file is part of Onyx, and is released under the terms of the MIT License
  * check LICENSE at the root directory for more information
+ *
+ * SPDX-License-Identifier: MIT
  */
 
 #include <onyx/fpu.h>
+#include <onyx/init.h>
+#include <onyx/mm/slab.h>
+#include <onyx/types.h>
+
+struct fpstate
+{
+    u64 regs[64] __attribute__((aligned(16)));
+    u32 fpsr;
+    u32 fpcr;
+};
 
-// FIXME: STUB
 void setup_fpu_area(unsigned char *address)
 {
 }
+
 void save_fpu(void *address)
 {
+    __asm__ __volatile__("stp q0, q1, [%0, #16 * 0]\n\t"
+                         "stp q2, q3, [%0, #16 * 2]\n\t"
+                         "stp q4, q5, [%0, #16 * 4]\n\t"
+                         "stp q6, q7, [%0, #16 * 6]\n\t"
+                         "stp q8, q9, [%0, #16 * 8]\n\t"
+                         "stp q10, q11, [%0, #16 * 10]\n\t"
+                         "stp q12, q13, [%0, #16 * 12]\n\t"
+                         "stp q14, q15, [%0, #16 * 14]\n\t"
+                         "stp q16, q17, [%0, #16 * 16]\n\t"
+                         "stp q18, q19, [%0, #16 * 18]\n\t"
+                         "stp q20, q21, [%0, #16 * 20]\n\t"
+                         "stp q22, q23, [%0, #16 * 22]\n\t"
+                         "stp q24, q25, [%0, #16 * 24]\n\t"
+                         "stp q26, q27, [%0, #16 * 26]\n\t"
+                         "stp q28, q29, [%0, #16 * 28]\n\t"
+                         "stp q30, q31, [%0, #16 * 30]\n\t"
+                         "mrs x1, fpsr\n\t"
+                         "str w1, [%0, #16 * 32]\n\t"
+                         "mrs x1, fpcr\n\t"
+                         "str w1, [%0, #16 * 32 + 4]\n" ::"r"(address)
+                         : "x1", "memory");
 }
+
 void restore_fpu(void *address)
 {
+    __asm__ __volatile__("ldp q0, q1, [%0, #16 * 0]\n\t"
+                         "ldp q2, q3, [%0, #16 * 2]\n\t"
+                         "ldp q4, q5, [%0, #16 * 4]\n\t"
+                         "ldp q6, q7, [%0, #16 * 6]\n\t"
+                         "ldp q8, q9, [%0, #16 * 8]\n\t"
+                         "ldp q10, q11, [%0, #16 * 10]\n\t"
+                         "ldp q12, q13, [%0, #16 * 12]\n\t"
+                         "ldp q14, q15, [%0, #16 * 14]\n\t"
+                         "ldp q16, q17, [%0, #16 * 16]\n\t"
+                         "ldp q18, q19, [%0, #16 * 18]\n\t"
+                         "ldp q20, q21, [%0, #16 * 20]\n\t"
+                         "ldp q22, q23, [%0, #16 * 22]\n\t"
+                         "ldp q24, q25, [%0, #16 * 24]\n\t"
+                         "ldp q26, q27, [%0, #16 * 26]\n\t"
+                         "ldp q28, q29, [%0, #16 * 28]\n\t"
+                         "ldp q30, q31, [%0, #16 * 30]\n\t"
+                         "ldr w1, [%0, #16 * 32]\n\t"
+                         "msr fpsr, x1\n\t"
+                         "ldr w1, [%0, #16 * 32 + 4]\n"
+                         "msr fpcr, x1\n\t" ::"r"(address)
+                         : "x1", "memory");
 }
+
 void fpu_ptrace_getfpregs(void *fpregs, struct user_fpregs_struct *regs)
 {
 }
-void fpu_init(void)
+
+static slab_cache *fpu_cache = nullptr;
+
+/**
+ * @brief Initialize the FPU state slab cache
+ *
+ */
+void fpu_init_cache()
+{
+    fpu_cache = kmem_cache_create("fpu-state", sizeof(fpstate), 16, 0, nullptr);
+    if (!fpu_cache)
+        panic("Out of memory allocating fpu state");
+}
+
+/**
+ * @brief Allocate an FPU state object from the allocator
+ *
+ * @return Pointer to FPU state, or nullptr
+ */
+void *fpu_allocate_state()
+{
+    return kmem_cache_alloc(fpu_cache, 0);
+}
+
+/**
+ * @brief Free FPU state object
+ *
+ * @param state Pointer to state
+ */
+void fpu_free_state(void *state)
 {
+    kmem_cache_free(fpu_cache, state);
 }
-size_t fpu_get_save_size(void)
+
+void fpu_init()
 {
-    return 0;
+    fpu_init_cache();
 }
-size_t fpu_get_save_alignment(void)
+
+INIT_LEVEL_EARLY_PLATFORM_ENTRY(fpu_init);
+
+size_t fpu_get_save_size()
+{
+    return sizeof(fpstate);
+}
+
+size_t fpu_get_save_alignment()
 {
-    return 1;
+    return 16;
 }