ZealBooter: Misc progress

build/build-temp-vm-uefi-1.sh

@@ -35,9 +35,13 @@ umount_tempdisk() {
 
 [ ! -d $TMPMOUNT ] && mkdir -p $TMPMOUNT
 
+set -e
+
 echo "Building ZealBooter..."
 ( cd ../zealbooter && make clean all )
 
+set +e
+
 echo "Making temp vdisk, running auto-install..."
 qemu-img create -f raw $TMPDISK 192M
 qemu-system-x86_64 -machine q35,accel=kvm -drive format=raw,file=$TMPDISK -m 1G -rtc base=localtime -cdrom AUTO-VM-1.ISO -device isa-debug-exit

src/Kernel/KStart32.ZC

@@ -77,6 +77,10 @@ SYS_SEMAS::				DU8 	SEMA_SEMAS_NUM * DEFAULT_CACHE_LINE_WIDTH DUP(0);
 //************************************
 		ALIGN 	16, OC_NOP
 
+        // Signature to find CORE0_32BIT_INIT
+        DU64 0xaa23c08ed10bd4d7;
+        DU64 0xf6ceba7d4b74179a;
+
 CORE0_32BIT_INIT:: //Entry point for $LK,"BootRAM",A="MN:BootRAM"$.
 		PUSH	U32 RFLAGG_START
 		POPFD

zealbooter/GNUmakefile

@@ -21,7 +21,7 @@ $(eval $(call DEFAULT_VAR,CC,cc))
 $(eval $(call DEFAULT_VAR,LD,ld))
 
 # User controllable CFLAGS.
-CFLAGS ?= -O2 -g -Wall -Wextra -Wpedantic -pipe
+CFLAGS ?= -O2 -g -Wall -Wextra -pipe
 
 # User controllable preprocessor flags. We set none by default.
 CPPFLAGS ?=
@@ -35,7 +35,7 @@ LDFLAGS ?=
 # Internal C flags that should not be changed by the user.
 override CFLAGS +=       \
     -I.                  \
-    -std=c11             \
+    -std=gnu11           \
     -ffreestanding       \
     -fno-stack-protector \
     -fno-stack-check     \

zealbooter/lib.c

@@ -0,0 +1,105 @@
+#include <stdint.h>
+#include <stddef.h>
+#include <lib.h>
+
+void *memcpy(void *dest, const void *src, size_t n) {
+    uint8_t *pdest = (uint8_t *)dest;
+    const uint8_t *psrc = (const uint8_t *)src;
+
+    for (size_t i = 0; i < n; i++) {
+        pdest[i] = psrc[i];
+    }
+
+    return dest;
+}
+
+void *memset(void *s, int c, size_t n) {
+    uint8_t *p = (uint8_t *)s;
+
+    for (size_t i = 0; i < n; i++) {
+        p[i] = (uint8_t)c;
+    }
+
+    return s;
+}
+
+void *memmove(void *dest, const void *src, size_t n) {
+    uint8_t *pdest = (uint8_t *)dest;
+    const uint8_t *psrc = (const uint8_t *)src;
+
+    if (src > dest) {
+        for (size_t i = 0; i < n; i++) {
+            pdest[i] = psrc[i];
+        }
+    } else if (src < dest) {
+        for (size_t i = n; i > 0; i--) {
+            pdest[i-1] = psrc[i-1];
+        }
+    }
+
+    return dest;
+}
+
+int memcmp(const void *s1, const void *s2, size_t n) {
+    const uint8_t *p1 = (const uint8_t *)s1;
+    const uint8_t *p2 = (const uint8_t *)s2;
+
+    for (size_t i = 0; i < n; i++) {
+        if (p1[i] != p2[i])
+            return p1[i] < p2[i] ? -1 : 1;
+    }
+
+    return 0;
+}
+
+char *strcpy(char *dest, const char *src) {
+    size_t i;
+
+    for (i = 0; src[i]; i++)
+        dest[i] = src[i];
+
+    dest[i] = 0;
+
+    return dest;
+}
+
+char *strncpy(char *dest, const char *src, size_t n) {
+    size_t i;
+
+    for (i = 0; i < n && src[i]; i++)
+        dest[i] = src[i];
+    for ( ; i < n; i++)
+        dest[i] = 0;
+
+    return dest;
+}
+
+int strcmp(const char *s1, const char *s2) {
+    for (size_t i = 0; ; i++) {
+        char c1 = s1[i], c2 = s2[i];
+        if (c1 != c2)
+            return c1 - c2;
+        if (!c1)
+            return 0;
+    }
+}
+
+int strncmp(const char *s1, const char *s2, size_t n) {
+    for (size_t i = 0; i < n; i++) {
+        char c1 = s1[i], c2 = s2[i];
+        if (c1 != c2)
+            return c1 - c2;
+        if (!c1)
+            return 0;
+    }
+
+    return 0;
+}
+
+size_t strlen(const char *str) {
+    size_t len;
+
+    for (len = 0; str[len]; len++);
+
+    return len;
+}

zealbooter/lib.h

@@ -0,0 +1,37 @@
+#ifndef __LIB_H__
+#define __LIB_H__
+
+#include <stddef.h>
+
+#define DIV_ROUNDUP(A, B) ({ \
+    typeof(A) _a_ = A;       \
+    typeof(B) _b_ = B;       \
+    (_a_ + (_b_ - 1)) / _b_; \
+})
+
+#define ALIGN_UP(A, B) ({        \
+    typeof(A) _a__ = A;           \
+    typeof(B) _b__ = B;           \
+    DIV_ROUNDUP(_a__, _b__) * _b__; \
+})
+
+#define ALIGN_DOWN(A, B) ({ \
+    typeof(A) _a_ = A;      \
+    typeof(B) _b_ = B;      \
+    (_a_ / _b_) * _b_;      \
+})
+
+typedef char symbol[];
+
+void *memcpy(void *dest, const void *src, size_t n);
+void *memset(void *s, int c, size_t n);
+void *memmove(void *dest, const void *src, size_t n);
+int memcmp(const void *s1, const void *s2, size_t n);
+
+char *strcpy(char *dest, const char *src);
+char *strncpy(char *dest, const char *src, size_t n);
+int strcmp(const char *s1, const char *s2);
+int strncmp(const char *s1, const char *s2, size_t n);
+size_t strlen(const char *str);
+
+#endif

zealbooter/lower.S

@@ -0,0 +1,36 @@
+.section .text
+
+.global lower
+lower:
+    pushq $0x18
+    addq $(1f - lower), %rax
+    pushq %rax
+    lretq
+
+    .code32
+    1:
+
+    mov $0x20, %eax
+    mov %eax, %ds
+    mov %eax, %es
+    mov %eax, %fs
+    mov %eax, %gs
+    mov %eax, %ss
+
+    lgdt (%ecx)
+
+    mov %cr0, %eax
+    btr $31, %eax
+    mov %eax, %cr0
+
+    mov $0xc0000080, %ecx
+    xor %eax, %eax
+    xor %edx, %edx
+    wrmsr
+
+    mov %ebx, %eax
+    mov $2, %ebx
+
+    mov $0x7c00, %esp
+    jmp *%eax
+

zealbooter/zealbooter.c

@@ -1,47 +1,198 @@
 #include <stdint.h>
 #include <stddef.h>
 #include <limine.h>
-
-// The Limine requests can be placed anywhere, but it is important that
-// the compiler does not optimise them away, so, usually, they should
-// be made volatile or equivalent.
+#include <lib.h>
 
 static volatile struct limine_module_request module_request = {
     .id = LIMINE_MODULE_REQUEST,
     .revision = 0
 };
 
-static volatile struct limine_terminal_request terminal_request = {
-    .id = LIMINE_TERMINAL_REQUEST,
+static volatile struct limine_kernel_address_request kernel_address_request = {
+    .id = LIMINE_KERNEL_ADDRESS_REQUEST,
     .revision = 0
 };
 
-static void done(void) {
-    for (;;) {
-        __asm__("hlt");
-    }
-}
-
-struct CKernel {
-
+static volatile struct limine_memmap_request memmap_request = {
+    .id = LIMINE_MEMMAP_REQUEST,
+    .revision = 0
 };
 
-// The following will be our kernel's entry point.
-void _start(void) {
-    // Ensure we got a terminal
-    if (terminal_request.response == NULL
-     || terminal_request.response->terminal_count < 1) {
-        done();
+struct CZXE {
+    uint16_t jmp;
+    uint8_t module_align_bits;
+    uint8_t reserved;
+    uint32_t signature;
+    int64_t org;
+    int64_t patch_table_offset;
+    int64_t file_size;
+};
+
+struct CDate {
+    uint32_t time;
+    int32_t date;
+};
+
+#define MEM_E820_ENTRIES_NUM 48
+
+#define MEM_E820T_USABLE 1
+#define MEM_E820T_RESERVED 2
+#define MEM_E820T_ACPI 3
+#define MEM_E820T_ACPI_NVS 4
+#define MEM_E820T_BAD_MEM 5
+#define MEM_E820T_PERM_MEM 7
+
+struct CMemE820 {
+    uint8_t *base;
+    int64_t len;
+    uint8_t type, pad[3];
+};
+
+struct CGDTEntry {
+    uint64_t lo, hi;
+};
+
+#define MP_PROCESSORS_NUM 128
+
+struct CGDT {
+    struct CGDTEntry null;
+    struct CGDTEntry boot_ds;
+    struct CGDTEntry boot_cs;
+    struct CGDTEntry cs32;
+    struct CGDTEntry cs64;
+    struct CGDTEntry cs64_ring3;
+    struct CGDTEntry ds;
+    struct CGDTEntry ds_ring3;
+    struct CGDTEntry tr[MP_PROCESSORS_NUM];
+    struct CGDTEntry tr_ring3[MP_PROCESSORS_NUM];
+};
+
+struct CKernel {
+    struct CZXE h;
+    uint32_t jmp;
+    uint32_t boot_src;
+    uint32_t boot_blk;
+    uint32_t boot_patch_table_base;
+    uint32_t sys_run_level;
+    struct CDate compile_time;
+    // start
+    uint32_t boot_base;
+    uint16_t mem_E801[2];
+    struct CMemE820 mem_E820[MEM_E820_ENTRIES_NUM];
+    uint64_t mem_physical_space;
+    struct {
+        uint16_t limit;
+        uint8_t *base;
+    } __attribute__((packed)) sys_gdt_ptr;
+    uint16_t sys_pci_buses;
+    struct CGDT sys_gdt;
+    uint32_t sys_font_ptr;
+} __attribute__((packed));
+
+#define BOOT_SRC_RAM 2
+#define RLF_16BIT 0b01
+#define RLF_VESA  0b10
+
+void lower(void);
+
+struct E801 {
+    size_t lowermem;
+    size_t uppermem;
+};
+
+struct E801 get_E801(void) {
+    struct E801 E801 = {0};
+
+    for (size_t i = 0; i < memmap_request.response->entry_count; i++) {
+        struct limine_memmap_entry *entry = memmap_request.response->entries[i];
+
+        if (entry->type == LIMINE_MEMMAP_USABLE) {
+            if (entry->base == 0x100000) {
+                if (entry->length > 0xf00000) {
+                    E801.lowermem = 0x3c00;
+                } else {
+                    E801.lowermem = entry->length / 1024;
+                }
+            }
+            if (entry->base <= 0x1000000 && entry->base + entry->length > 0x1000000) {
+                E801.uppermem = ((entry->length - (0x1000000 - entry->base)) / 1024) / 64;
+            }
+        }
     }
 
-    // We should now be able to call the Limine terminal to print out
-    // a simple "Hello World" to screen.
-    struct limine_terminal *terminal = terminal_request.response->terminals[0];
-    terminal_request.response->write(terminal, "Hello World", 11);
-
-    struct limine_file *kernel = module_request.response->modules[0];
-    struct CKernel *CKernel = kernel->address;
-
-    // We're done, just hang...
-    done();
+    return E801;
+}
+
+void _start(void) {
+    struct limine_file *kernel = module_request.response->modules[0];
+    struct CKernel *CKernel = (void *)0x7c00;
+    memcpy(CKernel, kernel->address, kernel->size);
+
+    void *CORE0_32BIT_INIT;
+    for (uint64_t *p = (uint64_t *)CKernel; ; p++) {
+        if (*p != 0xaa23c08ed10bd4d7) {
+            continue;
+        }
+        p++;
+        if (*p != 0xf6ceba7d4b74179a) {
+            continue;
+        }
+        p++;
+        CORE0_32BIT_INIT = p;
+        break;
+    }
+
+    CKernel->boot_src = BOOT_SRC_RAM;
+    CKernel->boot_blk = 0;
+    CKernel->boot_patch_table_base = (uintptr_t)CKernel + CKernel->h.patch_table_offset;
+    CKernel->sys_run_level = RLF_VESA | RLF_16BIT;
+
+    CKernel->boot_base = (uintptr_t)&CKernel->jmp;
+
+    CKernel->sys_gdt.boot_ds.lo = 0x000093000000ffff;
+    CKernel->sys_gdt.boot_cs.lo = 0x00009a000000ffff;
+    CKernel->sys_gdt.cs32.lo = 0x00cf9a000000ffff;
+    CKernel->sys_gdt.cs64.lo = 0x00af9b000000ffff;
+    CKernel->sys_gdt.cs64_ring3.lo = 0x00affb000000ffff;
+    CKernel->sys_gdt.ds.lo = 0x00af93000000ffff;
+    CKernel->sys_gdt.ds_ring3.lo = 0x00aff3000000ffff;
+
+    CKernel->sys_gdt_ptr.limit = sizeof(CKernel->sys_gdt) - 1;
+    CKernel->sys_gdt_ptr.base = (void *)&CKernel->sys_gdt;
+
+    struct E801 E801 = get_E801();
+    CKernel->mem_E801[0] = E801.lowermem;
+    CKernel->mem_E801[1] = E801.uppermem;
+
+    for (size_t i = 0; i < memmap_request.response->entry_count; i++) {
+        struct limine_memmap_entry *entry = memmap_request.response->entries[i];
+
+        int our_type;
+        switch (entry->type) {
+            case LIMINE_MEMMAP_BOOTLOADER_RECLAIMABLE:
+            case LIMINE_MEMMAP_KERNEL_AND_MODULES:
+            case LIMINE_MEMMAP_USABLE:
+                our_type = MEM_E820T_USABLE; break;
+            case LIMINE_MEMMAP_ACPI_RECLAIMABLE:
+                our_type = MEM_E820T_ACPI; break;
+            case LIMINE_MEMMAP_ACPI_NVS:
+                our_type = MEM_E820T_ACPI_NVS; break;
+            case LIMINE_MEMMAP_BAD_MEMORY:
+                our_type = MEM_E820T_BAD_MEM; break;
+            case LIMINE_MEMMAP_RESERVED:
+            default:
+                our_type = MEM_E820T_RESERVED; break;
+        }
+
+        CKernel->mem_E820[i].base = (void *)entry->base;
+        CKernel->mem_E820[i].len = entry->length;
+        CKernel->mem_E820[i].type = our_type;
+    }
+
+    void *target_addr = (void *)lower - kernel_address_request.response->virtual_base;
+    target_addr += kernel_address_request.response->physical_base;
+
+    asm volatile ("jmp *%0" :: "a"(target_addr), "b"(CORE0_32BIT_INIT), "c"(&CKernel->sys_gdt_ptr) : "memory");
+
+    __builtin_unreachable();
 }