build: add a "user" arch to allow the kernel to run as a program on the host machine

arch/user/config.mk

@@ -0,0 +1,18 @@
+LD  := gcc
+CC  := gcc
+ASM := gcc
+OBJCOPY := objcopy
+STRIP := strip
+
+CFLAGS   :=
+ASMFLAGS := $(CFLAGS)
+LDFLAGS  :=
+
+ARCH_CFLAGS := -D_64BIT
+ARCH_LDFLAGS := 
+
+ARCH_DIR := arch/$(SOCKS_ARCH)
+
+ARCH_C_FILES := $(wildcard $(ARCH_DIR)/*.c) $(wildcard $(ARCH_DIR)/acpi/*.c)
+ARCH_ASM_FILES := $(wildcard $(ARCH_DIR)/*.S) $(wildcard $(ARCH_DIR)/acpi/*.S)
+ARCH_OBJ := $(addprefix $(BUILD_DIR)/,$(ARCH_C_FILES:.c=.o) $(ARCH_ASM_FILES:.S=.o))

arch/user/cpu.c

@@ -0,0 +1,24 @@
+#include <unistd.h>
+#include <socks/machine/cpu.h>
+
+int ml_init_bootcpu(void)
+{
+	return 0;
+}
+
+int ml_cpu_block_init(ml_cpu_block *p)
+{
+	return 0;
+}
+
+int ml_cpu_block_use(ml_cpu_block *p)
+{
+	return 0;
+}
+
+void ml_halt_cpu(void)
+{
+	while (1) {
+		sleep(100);
+	}
+}

arch/user/extra.mk

@@ -0,0 +1,13 @@
+run: $(BUILD_DIR)/$(KERNEL_EXEC)
+	@printf "    \033[1;93mEXEC\033[0m   $<\n"
+
+	@$(BUILD_DIR)/$(KERNEL_EXEC)
+
+debug: $(BUILD_DIR)/$(KERNEL_EXEC)
+	@if command -v gdb &> /dev/null; then \
+		gdb -tui $(BUILD_DIR)/$(KERNEL_EXEC) \
+	elif commad -v lldb &> /dev/null; then \
+		lldb -- $(BUILD_DIR)/$(KERNEL_EXEC) \
+	else \
+		printf "No debuggers available." \
+	endif

arch/user/hwlock.c

@@ -0,0 +1,27 @@
+#include <socks/machine/hwlock.h>
+#include <socks/compiler.h>
+
+void ml_hwlock_lock(ml_hwlock_t *lck)
+{
+	volatile int q = 0;
+	while (!__sync_bool_compare_and_swap(lck, 0, 1)) {
+		q++;
+	}
+}
+
+void ml_hwlock_unlock(ml_hwlock_t *lck)
+{
+	__sync_lock_release(lck);
+}
+
+void ml_hwlock_lock_irqsave(ml_hwlock_t *lck, unsigned long *flags)
+{
+	(void)flags;
+	ml_hwlock_lock(lck);
+}
+
+void ml_hwlock_unlock_irqrestore(ml_hwlock_t *lck, unsigned long flags)
+{
+	(void)flags;
+	ml_hwlock_unlock(lck);
+}

arch/user/include/arch/stdcon.h

@@ -0,0 +1,6 @@
+#ifndef ARCH_STDCON_H_
+#define ARCH_STDCON_H_
+
+extern void stdcon_init(void);
+
+#endif

arch/user/include/socks/machine/cpu.h

@@ -0,0 +1,15 @@
+#ifndef SOCKS_USER_CPU_H_
+#define SOCKS_USER_CPU_H_
+
+typedef struct ml_cpu_block {
+	int cpu_reserved;
+} ml_cpu_block;
+
+extern int ml_init_bootcpu(void);
+
+extern int ml_cpu_block_init(ml_cpu_block *p);
+extern int ml_cpu_block_use(ml_cpu_block *p);
+
+extern void ml_halt_cpu(void);
+
+#endif

arch/user/include/socks/machine/hwlock.h

@@ -0,0 +1,14 @@
+#ifndef SOCKS_USER_HWLOCK_H_
+#define SOCKS_USER_HWLOCK_H_
+
+#define ML_HWLOCK_INIT (0)
+
+typedef int ml_hwlock_t;
+
+extern void ml_hwlock_lock(ml_hwlock_t *lck);
+extern void ml_hwlock_unlock(ml_hwlock_t *lck);
+
+extern void ml_hwlock_lock_irqsave(ml_hwlock_t *lck, unsigned long *flags);
+extern void ml_hwlock_unlock_irqrestore(ml_hwlock_t *lck, unsigned long flags);
+
+#endif

arch/user/include/socks/machine/init.h

@@ -0,0 +1,8 @@
+#ifndef SOCKS_X86_64_INIT_H_
+#define SOCKS_X86_64_INIT_H_
+
+#include <stdint.h>
+
+extern int ml_init(uintptr_t arg);
+
+#endif

arch/user/include/socks/machine/irq.h

@@ -0,0 +1,5 @@
+#ifndef SOCKS_X86_64_IRQ_H_
+#define SOCKS_X86_64_IRQ_H_
+
+
+#endif

arch/user/include/socks/machine/pmap.h

@@ -0,0 +1,9 @@
+#ifndef SOCKS_X86_64_PMAP_H_
+#define SOCKS_X86_64_PMAP_H_
+
+#include <arch/paging.h>
+
+typedef pml4t_ptr_t ml_pmap_t;
+typedef uint64_t ml_pfn_t;
+
+#endif

arch/user/include/socks/machine/vm.h

@@ -0,0 +1,26 @@
+#ifndef SOCKS_USER_VM_H_
+#define SOCKS_USER_VM_H_
+
+#include <stdint.h>
+
+extern uintptr_t __pagemap_base(void);
+extern uintptr_t __pagemap_limit(void);
+
+/* kernel higher-half base virtual address. */
+#define VM_KERNEL_VOFFSET (__pagemap_base())
+
+/* direct page-mapping region.
+   NOTE that these are the maximum bounds of this region.
+   the actual size depends on the amount of physical
+   memory present. */
+#define VM_PAGEMAP_BASE   (__pagemap_base())
+#define VM_PAGEMAP_LIMIT  (__pagemap_limit())
+
+#define VM_PAGE_SIZE  0x1000
+#define VM_PAGE_MASK  (VM_PAGE_SIZE-1)
+#define VM_PAGE_SHIFT 12
+
+#define VM_PAGE_MIN_ORDER VM_PAGE_4K
+#define VM_PAGE_MAX_ORDER VM_PAGE_8M
+
+#endif

arch/user/init.c

@@ -0,0 +1,68 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <socks/init.h>
+#include <socks/memblock.h>
+#include <socks/vm.h>
+#include <socks/object.h>
+#include <socks/printk.h>
+#include <arch/stdcon.h>
+#include <sys/mman.h>
+
+#define PMEM_SIZE 0x2000000
+
+extern void kernel_init(uintptr_t arg);
+
+static void *pmem = NULL;
+
+static void early_vm_init(void)
+{
+	pmem = mmap(NULL, PMEM_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (pmem == MAP_FAILED) {
+		fprintf(stderr, "arch: cannot map physical memory buffer.");
+		abort();
+	}
+	
+	uintptr_t alloc_start = (uintptr_t)pmem + VM_PAGE_SIZE;
+	uintptr_t alloc_end = alloc_start + PMEM_SIZE;
+
+	memblock_init(alloc_start, alloc_end, (uintptr_t)pmem);
+	printk("memblock: allocating from [0x%llx-0x%llx]", alloc_start, alloc_end);
+}
+
+uintptr_t __pagemap_base(void)
+{
+	return (uintptr_t)pmem;
+}
+
+uintptr_t __pagemap_limit(void)
+{
+	return (uintptr_t)pmem + PMEM_SIZE - 1;
+}
+
+int ml_init(uintptr_t arg)
+{
+	stdcon_init();
+	print_kernel_banner();
+	early_vm_init();
+
+	memblock_add(0, PMEM_SIZE);
+
+	vm_zone_descriptor_t vm_zones[] = {
+		{ .zd_id = VM_ZONE_DMA, .zd_node = 0, .zd_name = "dma", .zd_base = 0x00, .zd_limit = 0xffffff },
+		{ .zd_id = VM_ZONE_NORMAL, .zd_node = 0, .zd_name = "normal", .zd_base = 0x1000000, .zd_limit = UINTPTR_MAX },
+	};
+
+	vm_bootstrap(vm_zones, sizeof vm_zones / sizeof vm_zones[0]);
+
+	object_bootstrap();
+	return 0;
+}
+
+int main(int argc, const char **argv)
+{
+	kernel_init(0);
+
+	munmap(pmem, PMEM_SIZE);
+	return 0;
+}

arch/user/stdcon.c

@@ -0,0 +1,27 @@
+#include <socks/libc/string.h>
+#include <socks/libc/ctype.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <socks/console.h>
+#include <socks/vm.h>
+#include <socks/printk.h>
+
+static void stdcon_write(console_t *con, const char *s, unsigned int len)
+{
+	for (unsigned int i = 0; i < len; i++) {
+		fputc(s[i], stdout);
+	}
+}
+
+static console_t stdcon = {
+	.c_name = "stdcon",
+	.c_flags = CON_BOOT,
+	.c_write = stdcon_write,
+	.c_lock = SPIN_LOCK_INIT,
+};
+
+void stdcon_init(void)
+{
+	console_register(&stdcon);
+	early_printk_init(&stdcon);
+}