Separate stivale tty code
This commit is contained in:
parent
dc360b9d95
commit
94e9aced54
4 changed files with 153 additions and 134 deletions
11
Makefile
11
Makefile
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@ -43,10 +43,12 @@ INTERNALLDFLAGS := \
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-nostdlib \
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-zmax-page-size=0x1000 \
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-static
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CFILES := $(wildcard $(SRC_DIR)/*.c)
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OBJ := $(BUILD_DIR)/$(notdir $(CFILES:.c=.o))
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HEADER_DEPS := $(BUILD_DIR)/$(notdir $(CFILES:.c=.d))
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rwildcard=$(foreach d,$(wildcard $(1:=/*)),$(call rwildcard,$d,$2) $(filter $(subst *,%,$2),$d))
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CFILES := $(shell find ./$(SRC_DIR) -type f -name '*.c')
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OBJ := $(subst $(SRC_DIR),$(BUILD_DIR),$(CFILES:.c=.o))
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HEADER_DEPS := $(OBJ:.o=.d))
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.PHONY: all
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all: $(KERNEL)
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@ -56,6 +58,7 @@ $(KERNEL): $(OBJ) | $(BIN_DIR)
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-include $(HEADER_DEPS)
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$(BUILD_DIR)/%.o: $(SRC_DIR)/%.c | $(BUILD_DIR)
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@mkdir -p $(@D)
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$(CC) $(CFLAGS) $(INTERNALCFLAGS) -c $< -o $@
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# create directories if they don't exist
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140
src/boot/stivale/stivale.c
Normal file
140
src/boot/stivale/stivale.c
Normal file
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@ -0,0 +1,140 @@
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#include <stdint.h>
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#include <stddef.h>
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#include <stivale2.h>
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// We need to tell the stivale bootloader where we want our stack to be.
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// We are going to allocate our stack as an array in .bss.
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static uint8_t stack[8192];
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// stivale2 uses a linked list of tags for both communicating TO the
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// bootloader, or receiving info FROM it. More information about these tags
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// is found in the stivale2 specification.
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// stivale2 offers a runtime terminal service which can be ditched at any
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// time, but it provides an easy way to print out to graphical terminal,
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// especially during early boot.
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// Read the notes about the requirements for using this feature below this
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// code block.
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static struct stivale2_header_tag_terminal terminal_hdr_tag = {
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// All tags need to begin with an identifier and a pointer to the next tag.
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.tag = {
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// Identification constant defined in stivale2.h and the specification.
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.identifier = STIVALE2_HEADER_TAG_TERMINAL_ID,
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// If next is 0, it marks the end of the linked list of header tags.
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.next = 0
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},
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// The terminal header tag possesses a flags field, leave it as 0 for now
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// as it is unused.
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.flags = 0
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};
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// We are now going to define a framebuffer header tag.
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// This tag tells the bootloader that we want a graphical framebuffer instead
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// of a CGA-compatible text mode. Omitting this tag will make the bootloader
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// default to text mode, if available.
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static struct stivale2_header_tag_framebuffer framebuffer_hdr_tag = {
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// Same as above.
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.tag = {
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.identifier = STIVALE2_HEADER_TAG_FRAMEBUFFER_ID,
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// Instead of 0, we now point to the previous header tag. The order in
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// which header tags are linked does not matter.
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.next = (uint64_t)&terminal_hdr_tag
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},
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// We set all the framebuffer specifics to 0 as we want the bootloader
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// to pick the best it can.
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.framebuffer_width = 0,
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.framebuffer_height = 0,
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.framebuffer_bpp = 0
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};
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// The stivale2 specification says we need to define a "header structure".
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// This structure needs to reside in the .stivale2hdr ELF section in order
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// for the bootloader to find it. We use this __attribute__ directive to
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// tell the compiler to put the following structure in said section.
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__attribute__((section(".stivale2hdr"), used))
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static struct stivale2_header stivale_hdr = {
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// The entry_point member is used to specify an alternative entry
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// point that the bootloader should jump to instead of the executable's
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// ELF entry point. We do not care about that so we leave it zeroed.
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.entry_point = 0,
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// Let's tell the bootloader where our stack is.
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// We need to add the sizeof(stack) since in x86(_64) the stack grows
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// downwards.
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.stack = (uintptr_t)stack + sizeof(stack),
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// Bit 1, if set, causes the bootloader to return to us pointers in the
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// higher half, which we likely want since this is a higher half kernel.
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// Bit 2, if set, tells the bootloader to enable protected memory ranges,
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// that is, to respect the ELF PHDR mandated permissions for the executable's
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// segments.
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// Bit 3, if set, enables fully virtual kernel mappings, which we want as
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// they allow the bootloader to pick whichever *physical* memory address is
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// available to load the kernel, rather than relying on us telling it where
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// to load it.
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// Bit 4 disables a deprecated feature and should always be set.
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.flags = (1 << 1) | (1 << 2) | (1 << 3) | (1 << 4),
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// This header structure is the root of the linked list of header tags and
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// points to the first one in the linked list.
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.tags = (uintptr_t)&framebuffer_hdr_tag
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};
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// We will now write a helper function which will allow us to scan for tags
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// that we want FROM the bootloader (structure tags).
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void *stivale2_get_tag(struct stivale2_struct *stivale2_struct, uint64_t id) {
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struct stivale2_tag *current_tag = (void *)stivale2_struct->tags;
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for (;;) {
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// If the tag pointer is NULL (end of linked list), we did not find
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// the tag. Return NULL to signal this.
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if (current_tag == NULL) {
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return NULL;
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}
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// Check whether the identifier matches. If it does, return a pointer
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// to the matching tag.
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if (current_tag->identifier == id) {
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return current_tag;
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}
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// Get a pointer to the next tag in the linked list and repeat.
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current_tag = (void *)current_tag->next;
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}
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}
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struct stivale2_struct_tag_terminal *term_str_tag = NULL;
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void *term_write_ptr = NULL;
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void (*term_write)(const char *string, size_t length) = NULL;
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// The following will be our kernel's entry point.
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void _start(struct stivale2_struct *stivale2_struct) {
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// Let's get the terminal structure tag from the bootloader.
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term_str_tag = stivale2_get_tag(stivale2_struct, STIVALE2_STRUCT_TAG_TERMINAL_ID);
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// Check if the tag was actually found.
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if (term_str_tag == NULL) {
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// It wasn't found, just hang...
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for (;;) {
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asm ("hlt");
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}
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}
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kernel_main();
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// We're done, just hang...
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for (;;) {
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asm ("hlt");
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}
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}
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void terminal_initialize() {
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// stub for stivale
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// Let's get the address of the terminal write function.
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term_write_ptr = (void *)term_str_tag->term_write;
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// Now, let's assign this pointer to a function pointer which
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// matches the prototype described in the stivale2 specification for
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// the stivale2_term_write function.
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term_write = term_write_ptr;
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}
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void tty_print(const char* str, int length) {
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term_write(str, length);
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}
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134
src/kernel.c
134
src/kernel.c
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@ -1,132 +1,6 @@
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#include <stdint.h>
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#include <stddef.h>
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#include <stivale2.h>
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#include <tty.h>
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// We need to tell the stivale bootloader where we want our stack to be.
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// We are going to allocate our stack as an array in .bss.
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static uint8_t stack[8192];
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// stivale2 uses a linked list of tags for both communicating TO the
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// bootloader, or receiving info FROM it. More information about these tags
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// is found in the stivale2 specification.
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// stivale2 offers a runtime terminal service which can be ditched at any
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// time, but it provides an easy way to print out to graphical terminal,
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// especially during early boot.
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// Read the notes about the requirements for using this feature below this
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// code block.
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static struct stivale2_header_tag_terminal terminal_hdr_tag = {
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// All tags need to begin with an identifier and a pointer to the next tag.
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.tag = {
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// Identification constant defined in stivale2.h and the specification.
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.identifier = STIVALE2_HEADER_TAG_TERMINAL_ID,
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// If next is 0, it marks the end of the linked list of header tags.
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.next = 0
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},
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// The terminal header tag possesses a flags field, leave it as 0 for now
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// as it is unused.
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.flags = 0
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};
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// We are now going to define a framebuffer header tag.
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// This tag tells the bootloader that we want a graphical framebuffer instead
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// of a CGA-compatible text mode. Omitting this tag will make the bootloader
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// default to text mode, if available.
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static struct stivale2_header_tag_framebuffer framebuffer_hdr_tag = {
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// Same as above.
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.tag = {
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.identifier = STIVALE2_HEADER_TAG_FRAMEBUFFER_ID,
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// Instead of 0, we now point to the previous header tag. The order in
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// which header tags are linked does not matter.
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.next = (uint64_t)&terminal_hdr_tag
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},
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// We set all the framebuffer specifics to 0 as we want the bootloader
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// to pick the best it can.
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.framebuffer_width = 0,
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.framebuffer_height = 0,
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.framebuffer_bpp = 0
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};
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// The stivale2 specification says we need to define a "header structure".
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// This structure needs to reside in the .stivale2hdr ELF section in order
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// for the bootloader to find it. We use this __attribute__ directive to
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// tell the compiler to put the following structure in said section.
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__attribute__((section(".stivale2hdr"), used))
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static struct stivale2_header stivale_hdr = {
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// The entry_point member is used to specify an alternative entry
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// point that the bootloader should jump to instead of the executable's
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// ELF entry point. We do not care about that so we leave it zeroed.
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.entry_point = 0,
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// Let's tell the bootloader where our stack is.
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// We need to add the sizeof(stack) since in x86(_64) the stack grows
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// downwards.
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.stack = (uintptr_t)stack + sizeof(stack),
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// Bit 1, if set, causes the bootloader to return to us pointers in the
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// higher half, which we likely want since this is a higher half kernel.
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// Bit 2, if set, tells the bootloader to enable protected memory ranges,
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// that is, to respect the ELF PHDR mandated permissions for the executable's
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// segments.
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// Bit 3, if set, enables fully virtual kernel mappings, which we want as
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// they allow the bootloader to pick whichever *physical* memory address is
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// available to load the kernel, rather than relying on us telling it where
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// to load it.
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// Bit 4 disables a deprecated feature and should always be set.
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.flags = (1 << 1) | (1 << 2) | (1 << 3) | (1 << 4),
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// This header structure is the root of the linked list of header tags and
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// points to the first one in the linked list.
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.tags = (uintptr_t)&framebuffer_hdr_tag
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};
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// We will now write a helper function which will allow us to scan for tags
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// that we want FROM the bootloader (structure tags).
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void *stivale2_get_tag(struct stivale2_struct *stivale2_struct, uint64_t id) {
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struct stivale2_tag *current_tag = (void *)stivale2_struct->tags;
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for (;;) {
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// If the tag pointer is NULL (end of linked list), we did not find
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// the tag. Return NULL to signal this.
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if (current_tag == NULL) {
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return NULL;
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}
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// Check whether the identifier matches. If it does, return a pointer
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// to the matching tag.
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if (current_tag->identifier == id) {
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return current_tag;
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}
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// Get a pointer to the next tag in the linked list and repeat.
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current_tag = (void *)current_tag->next;
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}
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}
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// The following will be our kernel's entry point.
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void _start(struct stivale2_struct *stivale2_struct) {
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// Let's get the terminal structure tag from the bootloader.
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struct stivale2_struct_tag_terminal *term_str_tag;
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term_str_tag = stivale2_get_tag(stivale2_struct, STIVALE2_STRUCT_TAG_TERMINAL_ID);
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// Check if the tag was actually found.
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if (term_str_tag == NULL) {
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// It wasn't found, just hang...
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for (;;) {
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asm ("hlt");
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}
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}
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// Let's get the address of the terminal write function.
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void *term_write_ptr = (void *)term_str_tag->term_write;
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// Now, let's assign this pointer to a function pointer which
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// matches the prototype described in the stivale2 specification for
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// the stivale2_term_write function.
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void (*term_write)(const char *string, size_t length) = term_write_ptr;
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// We should now be able to call the above function pointer to print out
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// a simple "Hello World" to screen.
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term_write("Hello World", 11);
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// We're done, just hang...
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for (;;) {
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asm ("hlt");
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}
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void kernel_main(void) {
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terminal_initialize();
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tty_print("Hello, world!", 12);
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}
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2
src/tty.h
Normal file
2
src/tty.h
Normal file
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@ -0,0 +1,2 @@
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void terminal_initialize();
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void tty_print(const char*, int length);
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