bad

lcrash/CMakeLists.txt

@@ -6,7 +6,7 @@ lw_project(lcrash
 )
 
 lw_add_executable(lcrash
-	SOURCES lcrash.c
+	SOURCES lcrash.c efi/memmap.c
 )
 add_executable(lcrashld IMPORTED)
 set_property(TARGET lcrashld PROPERTY IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/lcrash.ld)
@@ -15,3 +15,4 @@ set_property(TARGET lcrash PROPERTY LINK_DEPENDS
 	$<TARGET_FILE:LindowsCompilerSpec>
 )
 set_property(TARGET lcrash PROPERTY LINK_OPTIONS -nostdlib -Wl,-T,${CMAKE_CURRENT_SOURCE_DIR}/lcrash.ld)
+target_compile_options(lcrash PRIVATE -ggdb)

lcrash/lcrash.c

@@ -1,4 +1,6 @@
 #include "lnxboot.h"
+#include "efi/types.h"
+#include "efi/memmap.h"
 
 extern void _start();
 
@@ -7,7 +9,7 @@ extern void _start();
 [[gnu::aligned(1)]]
 [[gnu::unavailable("not present at runtime. use setup_info instead")]]
 struct setup_info bzhead = {
-	.setup_sects = 1, // 1 512-byte sector
+	.setup_sects = 2, // 1 512-byte sector
 	.boot_flag = 0xAA55,
 	.syssize = 16,
 	.jump_instruction = 0xEB,
@@ -16,7 +18,7 @@ struct setup_info bzhead = {
 	.version = 0x020F,
 	.loadflags = 0x01, // LOADED_HIGH,
 	.kernel_alignment = 1,
-	.relocatable_kernel = 1,
+	.relocatable_kernel = 0,
 	.xloadflags = 0x13, // XLF_KERNEL_64 | XLF_CAN_BE_LOADED_ABOVE_4G | XLF_5LEVEL
 	.cmdline_size = 255, // max command line size
 	.init_size = 0x10000 // we dont need THAT much memory
@@ -60,8 +62,31 @@ void serial_put_formatted_u64(u64 v) {
 	}
 }
 
-[[gnu::section(".text._start"), gnu::naked]]
+/**
+ * We can't do anything, just hang.
+ */
+[[noreturn, gnu::naked]]
+void Hang() {
+	// This should make us hang
+	asm volatile (
+		"   cli\n"
+		"1: hlt\n"
+		"   jmp 1b"
+	);
+}
+
+/**
+ * Congratulations, you panicked twice!
+ */
+[[noreturn]]
+void Panic(const char* message) {
+	// We don't even do anything with the message, but it's nice to have just in case.
+	Hang();
+}
+
+[[gnu::section(".text._start"), gnu::naked, gnu::no_reorder]]
 extern void _start() {
+	asm ("jmp _start");
 	asm ( // grab the setup_info and boot_params locations
 	      	  "mov  %%rsi,  %1\n"
 		  "mov  %%rsi,  %0\n"
@@ -72,27 +97,70 @@ extern void _start() {
 	asm ("jmp entry");
 }
 
-[[gnu::section(".text._start")]]
+c16* FirmwareVendor = 0;
+
+/**
+ * we're in some kind of purgatory between booted and not booted, a lot of devices are currently initialized from the previous
+ * kernel, but we have no idea where they are, what they are, or how to use them. all we have is the stuff in setup_info and
+ * boot_params, and whatever we can salvage from the crashed kernel.
+ */
+[[gnu::section(".text._start"), gnu::no_reorder]]
 void entry() {
-	// get the zero page
+	// get command line from kernel. we likely won't use it, but its nice to have.
-	//boot_params = (struct boot_params*)(
+	u8* cmdline_ptr = (u8*)((u64)setup_info->cmd_line_ptr | ((u64)boot_params->ext_cmd_line_ptr << 32));	
-	//		  0x202 - 0x1f1
+	
-	//		+ setup_info->jump_offset
+	// do we have efi?
-	//		+ (u64)setup_info);
+	struct EfiSystemTable* systab_ptr = 0;
+	if (boot_params) {
+	       	systab_ptr = (struct EfiSystemTable*)(
+			(u64)boot_params->efi_info.EfiSystemTable |
+			((u64)boot_params->efi_info.EfiSystemTableHigh << 32)
+		);
 
-	// orignally we would try to import the serial port from the kernel (see kexec tools)
+		EfiLoadStoredMemoryMap(
-	// as you can see, we gave up!
+			(struct EfiMemoryDescription*)(
-	// serial_port = (unsigned short)*(long*)&serial_base;
+				(u64)boot_params->efi_info.EfiMemoryMap |
-	serial_port = 0x3f8;
+				((u64)boot_params->efi_info.EfiMemoryMapHigh << 32)
+			), // this might be 0, we should probably check ---------------V
+			boot_params->efi_info.EfiMemoryMapSize / boot_params->efi_info.EfiMemoryDescriptionSize,
+			boot_params->efi_info.EfiMemoryDescriptionSize
+		);
 
-	// construct pointers
+		FirmwareVendor = EfiTranslatePointer(systab_ptr->FirmwareVendor);
-	u8* cmdline_ptr = (u8*)((u64)setup_info->cmd_line_ptr | ((u64)boot_params->ext_cmd_line_ptr << 32));
+		while (1) {
+			volatile char* a = FirmwareVendor;
+		}
+	}
 
-	// check out command line
+	// -- find acpi --
-	serial_puts(cmdline_ptr);
+	struct AcpiRSDP* AcpiRSDP = 0;
-	serial_putc('\r');
-	serial_putc('\n');
 
+	// check bootparams
+	if (boot_params->acpi_rsdp_addr) AcpiRSDP = boot_params->acpi_rsdp_addr;
+
+	// check efi
+	if (!AcpiRSDP && systab_ptr && systab_ptr->NumberOfTableEntries) {
+		volatile void* ConfigurationTable = EfiTranslatePointer(systab_ptr->ConfigurationTable);
+	}
+
+	// we're playing where's waldo with this stupid fucking tableS
+	if (!AcpiRSDP) {
+		for (struct AcpiRSDP* addr = 0x00000000; addr < 0x000FFFFF; addr = (void*)addr + 16) {
+			if (addr->Signature[0] == 'R' && addr->Signature[1] == 'S'
+			 && addr->Signature[2] == 'D' && addr->Signature[3] == ' '
+			 && addr->Signature[4] == 'P' && addr->Signature[5] == 'T'
+			 && addr->Signature[6] == 'R' && addr->Signature[7] == ' ') {
+				AcpiRSDP = addr;
+				break;
+			}
+		}
+	}
+
+	if (!AcpiRSDP) Panic("Failed to find ACPI RSDP");
+
+	// do we have acpi?
+	asm volatile ("ljmp 0");
+	
 	// we dont have the privilege of getting a rodata segment. any reads off our stack cause a triple fault
 	// for some fucking reason. allocate our strings and shit on the stack.
 	//char s_you_fucked_up[] = "!!! YOU FUCKED UP !!!\n";
@@ -124,6 +192,5 @@ void entry() {
 	// serial_puts(bzhead.cmd_line_ptr);
 	
 	// Die.
-	asm ("cli");
+	Panic("Nothing left to do.");
-	asm ("hlt");
 }

lcrash/lcrash.ld

@@ -1,24 +1,36 @@
 OUTPUT_FORMAT(elf64-x86-64)
 
+ENTRY(_start)
+
+MEMORY {
+	code (rx) : ORIGIN = 0x0dfe8000, LENGTH = 0x00001000
+	data (rw) : ORIGIN = 0x0dff0000, LENGTH = 0x00001000
+}
+
 SECTIONS {
 	.lnxhead 0x01f1 : ALIGN(1) {
 		*(.lnxhead);
 	}
 
-	.rodata 0x900000 : ALIGN(1) {
+	.rodata : ALIGN(1) {
 		*(.rodata);
-	}
+	} > data
 
-	.text._start 0x80000000 : ALIGN(1) {
+	/* this section helps us to coerce the linker into not breaking down because of big addresses */
+	.text._start 0xdfe8000 : ALIGN(1) {
 		*(.text._start);
-	}
+	} > code
 
-	.text : ALIGN(512) { *(.text); }
+	.text : ALIGN(512) { *(.text); } > code
 	.bss : { *(.bss); }
 
-	.kernel_imports 0xFFFFFFFF : {
+	.debug_info 0 : { *(.debug_info); }
-		*(.kernel_imports);
+	.debug_abbrev 0 : { *(.debug_abbrev); }
-	}
+	.debug_aranges 0 : { *(.debug_aranges); }
+	.debug_rnglists 0 : { *(.debug_rnglists); }
+	.debug_line 0 : { *(.debug_line); }
+	.debug_str 0 : { *(.debug_str); }
+	.debug_line_str 0 : { *(.debug_line_str); }
 
 	/DISCARD/ : {
 		*(*);

lcrash/lnxboot.h

@@ -1,9 +1,7 @@
 #pragma once
 
-typedef unsigned char      u8;
+#include "types.h"
-typedef unsigned short     u16;
+#include "acpi/acpi.h"
-typedef unsigned int       u32;
-typedef unsigned long long u64;
 
 struct [[gnu::packed]] setup_info {
 	u8  setup_sects;
@@ -61,13 +59,14 @@ struct [[gnu::packed]] screen_info {
 	u16 reserved2;
 	u8  orig_video_lines;
 	u8  orig_video_isVGA;
-	u8  orig_video_points;
+	u16  orig_video_points;
 
 	// linear frame buffer
 	u16 lfb_width;
 	u16 lfb_height;
 	u16 lfb_depth;
 	u32 lfb_base;
+	u32 lfb_size;
 	u16 cl_magic;
 	u16 cl_offset;
 	u16 lfb_linelength;
@@ -79,8 +78,8 @@ struct [[gnu::packed]] screen_info {
 	u8  blue_pos;
 	u8  reserved_size;
 	u8  reserved_pos;
-	u8  vesapm_seg;
+	u16 vesapm_seg;
-	u8  vesapm_off;
+	u16 vesapm_off;
 	u16 pages;
 	u16 vesa_attributes;
 	u32 capabilities;
@@ -106,11 +105,20 @@ struct [[gnu::packed]] edid_info {
 };
 
 struct [[gnu::packed]] efi_info {
-	u8 pad[0x20];
+	u32 EfiLoaderSignature;
+	u32 EfiSystemTable;
+	u32 EfiMemoryDescriptionSize;
+	u32 EfiMemoryDescriptionVersion;
+	u32 EfiMemoryMap;
+	u32 EfiMemoryMapSize;
+	u32 EfiSystemTableHigh;
+	u32 EfiMemoryMapHigh;
 };
 
 struct [[gnu::packed]] e820_entry {
-	u8 pad;
+	u64 base;
+	u64 length;
+	u32 type;
 };
 
 struct [[gnu::packed]] edd_info {
@@ -123,8 +131,8 @@ struct [[gnu::packed]] boot_params {
 	u8                    reserved0[0x4];
 	void*                 tboot_addr;
 	struct ist_info       ist_info;
-	void*                 acpi_rsdp_addr;
+	struct acpi_rsdp*     acpi_rsdp_addr;
-	u8                    reserved1[0x2];
+	u8                    reserved1[0x8];
 	u8                    hd0_info[0x10];
 	u8                    hd1_info[0x10];
 	struct sys_desc_table sys_desc_table;
@@ -136,7 +144,7 @@ struct [[gnu::packed]] boot_params {
 	/// cmd_line_ptr high 32 bits
 	u32                   ext_cmd_line_ptr;
 	u8                    reserved2[0x70];
-	void*                 cc_blob_address;
+	u32                   cc_blob_address;
 	struct edid_info      edid_info;
 	struct efi_info       efi_info;
 	u32                   alt_mem_k;
@@ -150,7 +158,7 @@ struct [[gnu::packed]] boot_params {
 	u8                    sentinel;
 	u8                    reserved4[0xa0]; // setup_info lives here!
 	u8                    edd_mbr_sig_buffer[0x40];
-	u8                    e20_table[0xa00];
+	struct e820_entry     e820_table[128];
 	u8                    reserved5[0x30];
 	u8                    eddbuf[0x1ec];
 };