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authorRegina König2022-09-07 23:24:55 +0200
committerRegina König2022-09-07 23:24:55 +0200
commit09e1b4fb40878ef29b8ca36b93172fcd89c70883 (patch)
treef731cd63f8a6511d1b1bbad6ed4eb01111e77995 /documentation
parenthiuhi (diff)
parentRename dir and experiment with cmdline options (diff)
downloadmemtest86-09e1b4fb40878ef29b8ca36b93172fcd89c70883.tar.gz
memtest86-09e1b4fb40878ef29b8ca36b93172fcd89c70883.tar.xz
memtest86-09e1b4fb40878ef29b8ca36b93172fcd89c70883.zip
Merge branch 'master' of git.openslx.org:openslx-ng/memtest86HEADmaster
Diffstat (limited to 'documentation')
-rw-r--r--documentation/DEBUG statement10
-rw-r--r--documentation/Debugging in Qemu41
-rw-r--r--documentation/GDB commands139
-rw-r--r--documentation/GNU-efi299
-rw-r--r--documentation/QEMU Monitor Commands39
-rw-r--r--documentation/debug statement1
-rw-r--r--documentation/debugcon11
-rw-r--r--documentation/gdb commands19
-rw-r--r--documentation/gdb with efi application0
-rw-r--r--documentation/memtest86_build_process/24_08_22_memtest_build_process244
-rw-r--r--documentation/todo12
11 files changed, 783 insertions, 32 deletions
diff --git a/documentation/DEBUG statement b/documentation/DEBUG statement
new file mode 100644
index 0000000..eb110ff
--- /dev/null
+++ b/documentation/DEBUG statement
@@ -0,0 +1,10 @@
+
+Library to include:
+#include "Library/DebugLib.h"
+
+DEBUG (("%a: %d\n", _FUNCTION_, _LINE_));
+
+example:
+
+DEBUG((EFI_D_INFO, "My Entry Point: 0x%08x\r\n",(CHAR16*)UefiMain));
+
diff --git a/documentation/Debugging in Qemu b/documentation/Debugging in Qemu
new file mode 100644
index 0000000..6d43b3e
--- /dev/null
+++ b/documentation/Debugging in Qemu
@@ -0,0 +1,41 @@
+#########################################
+# #
+# Ways to debug in Qemu #
+# #
+#########################################
+
+DEBUGCON
+###############
+
+-debugcon file:debug.log -global isa-debugcon.iobase=0x402
+
+SERIAL
+###############
+
+-serial stdio
+ redirects the virtual serial port to the host's terminal i/o
+
+TRACE
+###############
+
+-D ./qemu_log.txt
+-d guest_errors, nochain, exec, in_asm, out_asm, op, op_opt, op_ind, int, cpu, mmu, pcall, cpu_reset, unimp, page
+
+--trace "memory_region*"
+
+MONITOR
+###############
+
+-monitor stdio
+
+or
+
+Ctrl + Alt + 2 (Exit with Ctrl + Alt + 1)
+
+GDB - GNU DEBUGGER
+#####################
+
+-s -S (when starting qemu)
+
+(gdb) target remote localhost:1234
+(gdb) c
diff --git a/documentation/GDB commands b/documentation/GDB commands
new file mode 100644
index 0000000..8411f19
--- /dev/null
+++ b/documentation/GDB commands
@@ -0,0 +1,139 @@
+###################################################################
+###################### #############################
+### GDB COMMANDS ###
+###################### #############################
+###################################################################
+
+QEMU CONFIGURATION
+
+ qemu must be started with "-s" option
+ (shorthand for "-gdb tcp::1234")
+
+#
+# GDB PART
+#
+
+SYMBOL FILES
+ add-symbol-file /path/to/Hello.debug 0x... -s .data 0x...
+
+
+CONNECTION
+ - source gdbscript
+ (if a gdbscript is created, which contains
+ add-symbol-file commandos)
+
+ - target remote localhost:1234
+
+DISCONNECTION
+ - detach
+ break connection with target, target resumes execution
+ GDB Target
+ (RSP Client) (RSP Server)
+ D
+ O------------------------------>O
+ O RSP exchange
+ O<------------------------------O
+ OK
+ -disconnect
+ Simply break connection. Target stays at the point where execution terminated previously
+ Reconnection(target remote): resume debugging at the point where the previous connection was broken
+
+BREAKPOINTS
+
+ - b CoreHandleProtocol || or OutputString
+ - break *0x65fe447 || set breakpoint at address
+ - delete 2 || delete breakpoint no 2
+ - break sampleApp.c:nn=LineNumber
+
+
+INFORMATION
+
+ - info
+ address SYM || Get address for symbol SYM
+ symbol ADDR || Show symbol at specified address
+
+ all-registers || all registers & their contents
+
+ breakpoints
+
+ files || get Entry point + sections
+ files || Names of targets & files being debugged
+
+ functions || all function names in Program
+ functions UefiMain || show where this function occurs
+
+ line
+
+ types [regex] || list all types or with regex
+
+ args || Argument variables of current stack frame
+ locals || local variables of current stack frame
+ variables || all gloabl & static variables
+
+
+CONTROL FLOW
+
+ - c || continue
+ - next || move only one step forward
+ - bt || print back_trace of all stack frames
+ - stop || stop program until it reaches a different source line
+
+FILES (perhaps not applicable when debugging with QEMU)
+
+ - file MemtestEfi.efi || load file ...no debugging symbols found...done
+ - file || unload files
+
+LIST
+
+ - list || list specified function or line
+
+gdb --tui
+ - layout asm
+ - layout reg
+ - layout src
+
+ - tui enable
+ - tui disable
+
+ - next
+
+ - ctrl+x o || change active window
+
+ - ctrl+x 1 || use TUI layout with one window
+ - ctrl+x 2 || use TUI layout with two windows
+
+ - PgUp || scroll the active window one page up
+ - PgDn || scroll the active window one page down
+
+ - Up || scroll the active window one line up
+ - Down || scroll the active window one lin down
+ - Right
+ - Left
+
+ - C+L || refresh the screen
+
+VARIABLES
+ info locals
+ info variables
+ info args
+
+ || Set is the same as print except that the expression's value is not printed
+ || and is not put in the value history.
+ || if your program has a variable width, you get an error if you try to set
+ || a new value with just ‘set width=13’, because GDB has the command set width
+ || To avoid to set silently general variables to invalid values, ALWAYS use
+ || set var x=4
+ print x=4
+ set x=4 or set variable x=4
+ whatis x -> type = double
+
+DISSASEMBLE BINARIES
+ gdb -batch -ex 'file /bin/ls' -ex 'disassemble main'
+ Also, -ex 'set disassembly-flavor intel' before other -exs will result in Intel assembly syntax
+
+ gcc -O0 -ggdb3 -std=c99 -Wall -Wextra -pedantic -o main.out main.c
+ gdb -batch -ex "disassemble/rs myfunc" main.out
+
+
+
+
diff --git a/documentation/GNU-efi b/documentation/GNU-efi
new file mode 100644
index 0000000..40cd91f
--- /dev/null
+++ b/documentation/GNU-efi
@@ -0,0 +1,299 @@
+##################################################################################
+## ##
+## BUILDING HELLOWORLD.EFI WIH GNU-EFI ##
+## ##
+##################################################################################
+
+#################################################################################
+# SUMMARY #
+#################################################################################
+
+Minimal working example:
+
+ hello.c
+---------------------------------------------------------------------------------
+#include <efi.h>
+#include <efilib.h>
+
+EFI_STATUS
+EFIAPI
+efi_main (EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) {
+
+ InitializeLib(ImageHandle, SystemTable);
+ Print(L"Hello, world!\n");
+
+ return EFI_SUCCESS;
+}
+
+
+Makefile
+--------------------------------------------------------------------------------
+ARCH = $(shell uname -m | sed s,i[3456789]86,ia32,)
+
+OBJS = hello.o
+TARGET = hello.efi
+
+EFIINC = /usr/include/efi
+EFFINCS = -I$(EFIINC) -I$(EFIINC)/$(ARCH) -I$(EFIINC)/protocol
+EFILIB = /usr/lib
+EFI_CRT_OBJS = $(EFILIB)/crt0-efi-$(ARCH).o
+EFI_LDS = $(EFILIB)/elf_$(ARCH)_efi.lds
+
+CFLAGS = $(EFFINCS) -fno-stack-protector -fpic \
+ -fshort-wchar -mno-red-zone -Wall
+
+ifeq ($(ARCH),x86_64)
+ CFLAGS += -DEFI_FUNCTION_WRAPPER
+endif
+
+LDFLAGS = -nostdlib -znocombreloc -T $(EFI_LDS) -shared \
+ -Bsymbolic -L $(EFILIB) $(EFI_CRT_OBJS)
+
+all: $(TARGET)
+
+hello.so: $(OBJS)
+ ld $(LDFLAGS) $(OBJS) -o $@ -lefi -lgnuefi
+
+%.efi: %.so
+ objcopy -j .text -j .sdata -j .data -j .dynamic \
+ -j .dynsym -j .rel -j .rela -j .reloc \
+ --target=efi-app-$(ARCH) $^ $@
+
+-----
+Now expanded version in git
+
+Get ImageBase:
+ Run ./test.sh and then hello.efi...this prints ImageBase
+
+Get Offsets:
+ GDB
+ file hello.efi
+ -> get text and data offset
+ file
+ add-symbol-file hello.efi (ImageBase+text-off) -s .data (ImageBase+data-off)
+
+
+#################################################################################
+# https://wiki.osdev.org/GNU-EFI #
+#################################################################################
+
+GNU-EFI is a very lightweight developing environment to create UEFI applications.
+It is a set of libraries and headers for compiling UEFI applications with a
+system's native GCC.
+
+You can use host native compiler, then convert resulting ELF into UEFI-compatible
+PE.
+ OR
+Use GCC Cross-Compiler generating PE directly.
+
+*********************************************************************************
+* $ git clone https://git.code.sf.net/p/gnu-efi/code gnu-efi *
+* $ cd gnu-efi *
+* $ make *
+*********************************************************************************
+
+This should create
+* crt0-efi-x86_64.o:
+ A CRT0 (C runtime initialization code) that will call the
+ "efi_main" function
+
+* libgnuefi.a:
+ A library containing a single function (_relocate)
+ that is used by the CRT0
+
+* (optional) libefi.a:
+ A library containing convenience functions like CRC computation, string
+ length calculation, and easy text printing
+
+HEADERS can be used from:
+* /usr/include/efi (updated to the latest)
+* from EDK2 package
+* Or from gnu-efi/inc
+
+LINKER SCRIPT:
+* gnu-efi/gnuefi/elf_x86_64_efi.lds
+ OR
+* /usr/lib/elf_x86_64_efi.lds
+
+COMPILATION:
+$ gcc
+ -Ignu-efi-dir/inc || set this to the efi headers directory
+
+ -fpic || UEFI PE executable must be relocatable
+
+ -ffreestanding || there's no hosted gcc environment,
+ we don't have libc
+ -fno-stack-protector =
+ -fno-stack-check || stack must be strictly used,
+ || no additional canaries or
+ || pre-allocated local variable
+ || space allowed
+ -mno-red-zone =
+
+ -fshort-wchar || It is very important that UEFI
+ || uses 16bit characters
+ || (wide-characters or wchar_t,
+ || defined as CHAR16 in efi headers
+
+ -maccumulate-outgoing-args || function calls must include the
+ || number of argumnets passed to the
+ || functions
+
+ -c main.c -o main.o
+
+LINKING:
+$ ld -shared -Bsymbolic -Lgnu-efi-dir/x86_64/lib -Lgnu-efi-dir/x86_64/gnuefi \
+ -Tgnu-efi-dir/gnuefi/elf_x86_64_efi.lds \
+ gnu-efi-dir/x86_64/gnuefi/crt0-efi-x86_64.o \
+ main.o -o main.so -lgnuefi -lefi
+
+ -shared -Bsymbolic || tell GNU ld to create so (shared library)
+
+ -L and -T || Where to find the static GNU-EFI libraries
+ || (.a) and the linker script
+
+ .o || it is important to specify crt0 as the
+ || first. Should work as the last too, but
+ || some had problems
+
+ -l || linking with gnuefi is a must, as that
+ || contains the relocation code. Linking
+ || with efi is optional, but recommended
+
+CONVERT CHARED OBJECT TO EFI EXECUTABLE
+$ objcopy -j .text -j .sdata -j .data -j .dynamic -j .dynsym -j .rel -j .rela -j .rel.*
+ -j .rela.* -j .reloc --target efi-app-x86_64 --subsystem=10 main.so main.efi
+
+ -j || which sections to keep during convertion
+
+ --target efi-app-x86_64 || tells objcop to generate a PE32+ format,
+ || with architecture code 0x8664
+
+ --subsystem=10: || most important. Sets file type to UEFI
+ || executable in the PE header
+
+Now you can copy main.efi to your EFI System Partition, and after boot run it
+from the EFI Shell. Or you can rename it to EFI\BOOT\BOOTX64.EFI and it should
+be executed automatically on boot.
+
+
+LIBEFI.A
+
+Has wrappers for the most common UEFI functions, but you might need to call
+something not covered. For completeness, it provides:
+
+uefi_call_wrapper(func, numarg, ...);
+
+For example, the "Print" function used in our main.c and which accepts printf
+compatible arguments, is under the hood nothing else than a call to:
+
+uefi_call_wrapper(ST->ConOut->OutputString, 2, ST->ConOut, buffer);
+
+The biggest advantage of 'uefi_call_wrapper_ is that doesn't matter what ABI
+your gcc is using, it will always correctly translate thet into UEFI ABI. If,
+and only if you've used the correct gcc options, then you should be able to
+make the same call as:
+
+ST->ConOut->OutputString(ST->ConOut, buffer);
+
+
+#################################################################################
+# https://wiki.osdev.org/Debugging_UEFI_applications_with_GDB #
+#################################################################################
+
+Makefile at:
+https://sourceforge.net/p/ast-phoenix/code/ci/master/tree/kernel/boot/Makefile#l72
+
+EFI firmware is unable to launch binaries with debug sections. What you need is
+to create two EFI binaries - one with only required sections to upload it to
+target system and another one with debug symbols to use with GDB. Actually you
+just need to run objcopy utility twice with different set of sections to copy and
+different output files. (See Makefile example)
+
+To load image with symbols to relocated addresses for .text and .data sections,
+you need to add ImageBase address to their offsets:
+
+*********************************************************************************
+* # gdb hello.efi *
+* (gdb) info files *
+* ... *
+* Entry point: 0x3000 *
+* 3000 - ... is .text *
+* c00 - ... is .data *
+* (gdb) file || unload file *
+* add-symbol-file hello.efi (ImageBase+text-off) -s .data (ImageBase+data-off) *
+*********************************************************************************
+
+#################################################################################
+# https://www.rodsbooks.com/efi-programming/hello.html #
+#################################################################################
+
+You should not normally include regular C header files, such as stdlib.h,
+because most of these header files define data types and functions that are used
+by the C library. This library is not available in EFI.
+
+************************************
+* efi.h and efilib.h always needed *
+************************************
+
+Entry point: efi_main() in GNU-efi
+
+CFLAGS:
+* -fno-stack-protector:
+ Stack protection isn't suppoerted by EFI, so there's no point in
+ building a binary with this feature active.
+
+* -fpic:
+ EFI requires that code be position-independet, hence the use
+ of this option.
+
+* -fshort-wchar:
+ GCC defines the wchar_t type to be 32 bits by default, but EFI requires
+ it to be 16 bits for 16-bit strings to work correctly.
+
+* fmno-red-zone:
+ On x86-64 systems, the red zone is an area that follows the stack pointer
+ that can be used for temporary variables. The EFI may modify this area,
+ though, so it's not safe to use, and you must compile EFI binaries with
+ this option.
+
+* -Wall:
+ When developing EFI applications, you might want to pay extra attention to
+ compiler warnings, and this switch (which causes warnings to be treated as
+ errors) can help.
+
+* -DEFI_FUNCTION_WRAPPER:
+ This option is required on the x86_64 platform, but is not defined on the
+ 32-bit x86 platform. It relates to th calling conventions for EFI functions,
+ described on the Using EFI Services page.
+
+LDFLAGS:
+* -nostdlib:
+ An EFI application should not be linked against standard libraries, and this
+ argument accomplishes this goal.
+
+* -nocombreloc:
+ This argument causes the linker to not combine relocation sections.
+
+* -T $(EFI_LDS):
+ To create an EFI binary, a non-standard linker script must be used, and this
+ option tells ld where to find it.
+
+* -shared:
+ Even with GNU-EFI's new linker script, ld can't create the final executable.
+ Instead, it creates a shared library, which is subsequently
+ turned into the final binary.
+
+* -Bsymbolic:
+ This option causes references to global symbols to be bound to the
+ definitions within the shared library.
+
+
+
+
+
+
+
+
+
+
diff --git a/documentation/QEMU Monitor Commands b/documentation/QEMU Monitor Commands
new file mode 100644
index 0000000..bae7cf7
--- /dev/null
+++ b/documentation/QEMU Monitor Commands
@@ -0,0 +1,39 @@
+####################################################################
+#################### ###################
+### QEMU MONITOR COMMANDS ###
+#################### ###################
+####################################################################
+
+1. START QEMU MONITOR
+
+ - within viewer:
+ Ctrl + Alt + 2
+ exit with Ctrl + Alt + 1
+
+ - as QEMU parameter to get monitor in terminal:
+ -monitor stdio
+
+2. GET HELP
+
+ help
+ help info
+ help list
+
+3. SCROLL
+
+ Ctrl + PgUp/PgDown
+
+4. GDBSERVER
+
+ starts a remote session for the GNU debugger (gdb)
+ To connect to it from the host machine,
+ $gdb qemuKernelFile
+ target remote localhost:1234
+
+5. SHOW REGISTERS
+
+ info registers
+
+ eax = 32bit
+ rax = 64bit
+ rip = memory address of the next instruction to execute
diff --git a/documentation/debug statement b/documentation/debug statement
deleted file mode 100644
index a8e192c..0000000
--- a/documentation/debug statement
+++ /dev/null
@@ -1 +0,0 @@
-DEBUG (("%a: %d\n", _FUNCTION_, _LINE_));
diff --git a/documentation/debugcon b/documentation/debugcon
new file mode 100644
index 0000000..5d914f5
--- /dev/null
+++ b/documentation/debugcon
@@ -0,0 +1,11 @@
+#########################
+# #
+# DEBUGCON #
+# #
+#########################
+
+for debug already in early bootphases
+One can connect the I/O port to either a file or a device, like /dev/stdout
+ - debugcon /dev/stdout (terminal that started Qemu process)
+ - debugcon file:qemu/debug.log (or other file name)
+
diff --git a/documentation/gdb commands b/documentation/gdb commands
deleted file mode 100644
index 85bf88e..0000000
--- a/documentation/gdb commands
+++ /dev/null
@@ -1,19 +0,0 @@
-GDB COMMANDS
-============
-
-qemu must be started with "-s" option (shorthand for "-gdb tcp::1234")
-
-source gdbscript
-
-file MemtestEfi.efi || load file
-info files || get Entry point + sections
-file || unload files
-
-b CoreHandleProtocol | or OutputString
-
-target remote localhost:1234
-
-c
-bt || print back_trace of all stack frames
-stop || stop program until it reaches a different source line
-list || list specified function or line
diff --git a/documentation/gdb with efi application b/documentation/gdb with efi application
deleted file mode 100644
index e69de29..0000000
--- a/documentation/gdb with efi application
+++ /dev/null
diff --git a/documentation/memtest86_build_process/24_08_22_memtest_build_process b/documentation/memtest86_build_process/24_08_22_memtest_build_process
new file mode 100644
index 0000000..fc8f33c
--- /dev/null
+++ b/documentation/memtest86_build_process/24_08_22_memtest_build_process
@@ -0,0 +1,244 @@
+
+Linker scripts:
+ memtest_shared.lds
+ memtest_efi.lds
+boot/
+ header.S || The standard EFI header
+ setup.S
+ efisetup.c || Macros + private functions
+ || Only for 32-bit boot entry point???
+ startup64.S
+
+*.c files in app/, lib/, system/, tests/
+
+##########################################################################
+## ##
+## MEMTEST LINKING PART 1 - MEMTEST_SHARED ##
+## ##
+##########################################################################
+
+#
+# memtest_shared.lds
+#
+
+OUTPUT_FORMAT("elf64-x86-64")
+
+ENTRY(startup64); <--------- in startup64.S
+
+SECTIONS {
+ .text : {
+ _start = .; <---------- First section in memtest_shared-.text
+ *(.text)
+ *(.text.*)
+ ...
+
+ .rodata
+ .dynsym
+ .dynstr
+ .hash
+ .gnu.hash
+ .dynamic
+
+ .rela.text
+ .rela.rodata
+ .rela.data
+ .rela.got
+ .rela.plt
+
+ .data
+ .got
+ .bss
+
+#
+# startup64.S
+#
+118: .globl startup64
+119: startup64:
+120: cld
+121: cli
+
+ # Save the boot params pointer
+125: movq %rsi, boot_params_addr(%rip)
+
+127: jmp startup
+
+143: .globl startup
+144: startup:
+ Use startup stack until we pick a correct one
+ Pick the correct stack
+ Initialize the pml4 and pdp tables
+ Set the page directory base address
+ Initialise the GDT and the segment registers
+ Load the GDT and the segment registers
+ Initialise the IDT
+ Initialise the IDT descriptor
+ Zero the BSS (if first boot)
+ Initialise the FPU
+ Enable SSE
+ Call the dynamic linker to fix up the addresses in the GOT
+
+268: call reloc <---------------- system/reloc64.c:151
+ get_load_address()
+ get_dynamic_section_offset()
+ get_dynamic_info()
+ do_relocations
+
+276: call main <---------------- app/main.c:499 # main entry point called from the startup code
+
+#
+# Analysis of the binary
+#
+
+* objdump -h memtest_shared
+ .text ... File off Algn
+ 00200000 2**4
+
+* objdump -g memtest_shared | grep efi_setup # check for occurences
+ | grep efi_handover
+
+* readelf -h memtest_shared
+ ELF Header:
+ Magic: 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00
+ Class: ELF64
+ Data: 2's complement, little endian
+ Version: 1 (current)
+ OS/ABI: UNIX - System V
+ ABI Version: 0
+ Type: DYN (Shared object file)
+ Machine: Advanced Micro Devices X86-64
+ Version: 0x1
+ Entry point address: 0x200 <-----------------That's startup64 !!!
+ Start of program headers: 64 (bytes into file)
+ Start of section headers: 2821656 (bytes into file)
+ Flags: 0x0
+ Size of this header: 64 (bytes)
+ Size of program headers: 56 (bytes)
+ Number of program headers: 3
+ Size of section headers: 64 (bytes)
+ Number of section headers: 26
+ Section header string table index: 25
+
+* objdump -d memtest_shared
+ memtest_shared: file format elf64-x86-64
+
+ Disassembly of section .text:
+
+ 0000000000000000 <_start>:
+ 0: cld
+ 1: cli
+
+ 9f: ljmp *-0x6(%rsp)
+
+ 00000000000001e0 <efi_boot>:
+
+ 1ed: jmp 210 <efi_handover>
+
+ 0000000000000200 <startup64>:
+
+ 202: mov %rsi,0x23df7(%rip) # 2400 <boot_params_addr>
+ 209: jmp 220 <startup>
+
+ 0000000000000210 <efi_handover>:
+
+ 214: callq 68f <efi_setup>
+ 219: mov %rax,0x23de0(%rip) # 2400 <boot_params_addr>
+
+ 0000000000000220 <startup>:
+
+ 2ce: ljmp *-0x6(%rsp)
+
+
+
+##########################################################################
+## ##
+## MEMTEST LINKING PART 2 - MEMTEST.EFI ##
+## ##
+##########################################################################
+
+#
+# memtest_efi.lds
+#
+OUTPUT_FORMAT("binary")
+
+ENTRY(boot); <----- in boot/header.S:36
+
+SECTIONS {
+ .header : { <----- boot/header.S
+ *(.header)
+ }
+ .setup : { <----- boot/setup.S
+ *(.setup)
+ }
+ .text : {
+ _text_start = .;
+ *(.data) <----- !!! NO .text !!!!
+ ...
+
+#
+# header.S
+#
+The EFI loader loads the header at ImageBase, so we have to locate the main program
+after that. This means we can't load the main program at HIGH_LOAD_ADDR. Pick a load
+address well away from HIGH_LOAD_ADDR, to avoid overlap when relocating code.
+
+. # define IMAGE_BASE 0x200000
+. # define BASE_OF_CODE 0x1000 <- where do these values come from?????
+
+ .section ".header", "ax", @progbits
+ .code16
+
+ .globl boot
+
+boot:
+ "MZ", the MS-DOS header signature
+ .byte 0x4d
+ .byte 0x5a
+
+pe_header:
+
+coff_header:
+
+...
+
+#
+# setup.S
+#
+Collects memory map information from the BIOS, disables APM, enables A20 and performs
+the switch from real mode to protected mode before jumping to the main program entry
+point.
+
+The memory map information is stored in the 4KB block of memory immediately following
+the setup code. The layout of the information matches the Linux boot_params struct.
+A pointer to this block is passed to the main program, for compatibility with the Linux
+32-bit boot protocol.
+
+. # define BOOT_PARAMS_START (SETUP_SECS * 512) || SETUP_SEC is defined in boot.h
+. # define BOOT_PARAMS_END (BOOT_PARAMS_START + 4096) <--- here are the 4K
+
+ .section ".setup", "ax", @progbits
+ .code16
+
+Emulate the Linux boot header, to allow loading by other boot loaders. Indicate that the
+main program code should be loaded in high memory.
+
+ .globl setup
+setup: jmp do_setup
+
+101: do_setup:
+ Reload the segment registers, except for the stack
+ Get the memory map and disable APM
+ Disable interrupts
+ Enable A20
+ ...
+
+179: flush:
+ Reload the segment registers and jump to the main test program <------------!!!!
+
+ ...
+188: jump:
+ data32 ljmp $KERNEL_CS, $0
+
+
+
+389: Pad to the declared size
+ .org (ESTUP_SECS*512)
diff --git a/documentation/todo b/documentation/todo
deleted file mode 100644
index 5238731..0000000
--- a/documentation/todo
+++ /dev/null
@@ -1,12 +0,0 @@
-
-- gdb breakpoint
-
-- debug Symbole Memtest
-
-- AddressSanitizer
-
-- make vs make run
-
-- plugin to handle lto object
-
-- debug information by DEBUG ((---))