create elf.h

The ELF parser needs more work, there are more structs to be added.
memcpy was refactored from mem.h into common.h
endianness conversions were standardized in types.h

10 files changed, 103 insertions, 39 deletions

diff --git a/Makefile b/Makefile
index 2de743c..cc021ca 100644
--- a/Makefile
+++ b/Makefile
@@ -3,9 +3,10 @@ LD = ld.lld
 OBJCOPY = llvm-objcopy
 
 ARCH_FLAG = \
-   --target=riscv32-unknown-elf \
-   -march=rv32im \
-	-mabi=ilp32
+	--target=riscv32-unknown-elf \
+	-march=rv32im \
+	-mabi=ilp32 \
+	-D__SYS_LITTLE_ENDIAN__
 
 
 COMMON_FLAGS = \
diff --git a/include/common.h b/include/common.h
index 86f1f9c..88ee8c4 100644
--- a/include/common.h
+++ b/include/common.h
@@ -16,4 +16,11 @@ static inline int strcmp(const char *str1, const char* str2) {
     return *(const unsigned char *)str1 - *(const unsigned char *)str2;
 }
 
-
+static inline void *memcpy(void *restrict dest, const void* restrict src, size_t size) {
+    unsigned char *d = (unsigned char *)dest;
+    unsigned char *s = (unsigned char *)src;
+    for (size_t i = 0; i < size; i++) {
+        d[i] = s[i];
+    }
+    return d;
+}
diff --git a/include/elf.h b/include/elf.h
new file mode 100644
index 0000000..ad8c550
--- /dev/null
+++ b/include/elf.h
@@ -0,0 +1,47 @@
+#pragma once
+#include <types.h>
+
+#define ELF_MAGIC_LE 0x464C457F
+#define ELF_PAD 0
+
+#define EI_MAG0 0
+#define EI_MAG1 1
+#define EI_MAG2 2
+#define EI_MAG3 3
+#define EI_CLASS 4
+#define EI_DATA 5
+#define EI_VERSION 6
+#define EI_OSABI 7
+#define EI_ABI_VERSION 8
+
+struct elf_header {
+    uint8_t e_ident[16];
+    uint8_t e_type;
+    uint8_t e_machine;
+    uint8_t e_version;
+    uint8_t e_entry;
+    uint8_t e_phoff;
+    uint8_t e_shoff;
+    uint8_t e_flags;
+    uint8_t e_ehsize;
+    uint8_t e_phentsize;
+    uint8_t e_phnum;
+    uint8_t e_shentsize;
+    uint8_t e_shnum;
+    uint8_t e_shstrndx;
+};
+
+struct elf_section_header {
+    uint32_t sh_name;
+    uint32_t sh_type;
+    uint32_t sh_flags;
+    uint32_t sh_addr;
+    uint32_t sh_offset;
+    uint32_t sh_size;
+    uint32_t sh_link;
+    uint32_t sh_info;
+    uint32_t sh_addralign;
+    uint32_t sh_entsize;
+};
+
+int elf_chk_header(struct elf_header *header);
diff --git a/include/mem.h b/include/mem.h
index edba547..bd6c911 100644
--- a/include/mem.h
+++ b/include/mem.h
@@ -20,7 +20,5 @@ void* kmalloc(size_t size);
 void* kzalloc(size_t size);
 void kfree(void* ptr);
 
-void* memcpy(void* to, const void* from, size_t size);
-
 void km_init(struct mem_info *info);
 
diff --git a/include/types.h b/include/types.h
index 4c7965c..821e108 100644
--- a/include/types.h
+++ b/include/types.h
@@ -7,7 +7,30 @@
 #define uint16_t __wk_uint16_t
 #define uint32_t __wk_uint32_t
 #define uint64_t __wk_uint64_t
-#define be32_to_cpu(x) __builtin_bswap32(x)
+
+#define htole
+
+#ifdef __SYS_LITTLE_ENDIAN__
+    #define ltohs(x) x
+    #define ltohi(x) x
+    #define htols(x) x
+    #define htoli(x) x
+
+    #define btohs(x) __builtin_bswap16(x)
+    #define btohi(x) __builtin_bswap32(x)
+    #define htobs(x) __builtin_bswap16(x)
+    #define htobi(x) __builtin_bswap32(x)
+#else
+    #define ltohs(x) __builtin_bswap16(x)
+    #define ltohi(x) __builtin_bswap32(x)
+    #define htols(x) __builtin_bswap16(x)
+    #define htoli(x) __builtin_bswap32(x)
+
+    #define btohs(x) x
+    #define btohi(x) x
+    #define htobs(x) x
+    #define htobi(x) x
+#endif
 
 typedef __UINTPTR_TYPE__ __wk_size_t;
 typedef __UINT8_TYPE__ __wk_uint8_t;
diff --git a/kernel/bump.c b/kernel/bump.c
index 369f92f..fd4f25d 100644
--- a/kernel/bump.c
+++ b/kernel/bump.c
@@ -19,8 +19,8 @@ struct mem_info *km_find_memory(struct dt_node *head) {
                 size_t len = 0;
                 uint32_t *reg = (uint32_t *)dt_get_prop(head, "reg", &len);
                 if (reg && len >= 8) {
-                    uint32_t base = be32_to_cpu(reg[0]);
-                    uint32_t size = be32_to_cpu(reg[1]);
+                    uint32_t base = btohi(reg[0]);
+                    uint32_t size = btohi(reg[1]);
                     struct mem_info *ret = kemalloc(sizeof(struct mem_info));
                     ret->start = (void*)base;
                     ret->size = (size_t)size;
diff --git a/kernel/dtb.c b/kernel/dtb.c
index 99b1679..7647767 100644
--- a/kernel/dtb.c
+++ b/kernel/dtb.c
@@ -10,15 +10,15 @@ struct dt_node *dt_parse(void *fdt) {
         return NULL;
     }
 
-    uint32_t *p = (uint32_t *)(fdt + be32_to_cpu(hdr->off_dt_struct));
-    char *strings = fdt + be32_to_cpu(hdr->off_dt_strings);
+    uint32_t *p = (uint32_t *)(fdt + btohi(hdr->off_dt_struct));
+    char *strings = fdt + btohi(hdr->off_dt_strings);
 
     struct dt_node *root = NULL;
     struct dt_node *stack[DTB_MAX_NODES];
     int sp = 0;
 
     while (1) {
-        uint32_t token = be32_to_cpu(*p++);
+        uint32_t token = btohi(*p++);
         switch (token) {
             case FDT_BEGIN_NODE: {
                 char *name = (char *)p;
@@ -35,8 +35,8 @@ struct dt_node *dt_parse(void *fdt) {
                 break;
             }
             case FDT_PROP: {
-                uint32_t len = be32_to_cpu(*p++);
-                uint32_t nameoff = be32_to_cpu(*p++);
+                uint32_t len = btohi(*p++);
+                uint32_t nameoff = btohi(*p++);
                 void *value = p;
                 p += (len + 3) / 4;
 
diff --git a/kernel/elf.c b/kernel/elf.c
new file mode 100644
index 0000000..f1ceb2d
--- /dev/null
+++ b/kernel/elf.c
@@ -0,0 +1,12 @@
+#include <elf.h>
+#include <common.h>
+
+int elf_chk_header(struct elf_header *header) {
+    uint32_t magic_chk;
+    memcpy(&magic_chk, header->e_ident, sizeof(uint32_t));
+    if (magic_chk != ltohi(ELF_MAGIC_LE)) {
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/kernel/kernel.c b/kernel/kernel.c
index 3952f8f..da44428 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -1,18 +1,6 @@
 #include <types.h>
 #include <dtb.h>
 #include <bump.h>
-#define UART_BASE 0x10000000  // Example UART address
-
-static inline void putchar(char c) {
-    volatile char *uart = (volatile char *)UART_BASE;
-    *uart = c;
-}
-
-static void print_string(const char *str) {
-    while (*str) {
-        putchar(*str++);
-    }
-}
 
 void kernel_main(size_t hart, void *fdt) {
     (void)hart;
@@ -21,11 +9,11 @@ void kernel_main(size_t hart, void *fdt) {
     struct mem_info *info = km_find_memory(head);
 
     if (!info) {
-        print_string("failed to get memory!\n");
         while (1);
     }
 
     km_init(info);
 
+
     while(1);
 }
diff --git a/kernel/mem.c b/kernel/mem.c
index 0556dfb..2a6bd35 100644
--- a/kernel/mem.c
+++ b/kernel/mem.c
@@ -106,18 +106,6 @@ void kfree(void *ptr) {
 }
 
 
-
-void* memcpy(void *to, const void *from, size_t size) {
-    char *dest = (char *)to;
-    const char *src = (const char *)from;
-
-    while (size--) {
-        *dest++ = *src++;
-    }
-
-    return dest;
-}
-
 void km_init(struct mem_info *info) {
     struct page *base = (struct page *)info->start;
     base->next = NULL;