Revised Virtual Memory

.github/workflows/os_test.yml

@@ -15,15 +15,26 @@ jobs:
             path: toolchain
             key: toolchain
 
+      - name: Cache Qemu
+        id: cache-qemu
+        uses: actions/cache@v1
+        with:
+            path: qemu/qemu
+            key: qemu
+
       - name: Install Dependencies
         run: |
           sudo apt-get update &&
-          sudo apt-get install build-essential qemu-system-arm python3 wget texinfo zlib1g-dev -y
+          sudo apt-get install build-essential python3 wget texinfo zlib1g-dev -y
 
-      - name: Install Toolchain
-        #if: steps.cache-toolchain.outputs.cache-hit != 'true'
+      - name: Build Toolchain
+        if: steps.cache-toolchain.outputs.cache-hit != 'true'
         run: rm -rf toolchain/arm-none-eabi/ && make toolchain
 
+      - name: Build Qemu
+        if: steps.cache-qemu.outputs.cache-hit != 'true'
+        run: rm -rf qemu/qemu* && make qemu
+
       - name: Compile
         run: make build
 

.gitignore

@@ -46,3 +46,5 @@ uboot-commands.ubt
 
 NOTES
 /server.PID
+
+!/.idea/

Makefile

@@ -1,9 +1,15 @@
-all: toolchain kernel
+all: requirements kernel
 
 toolchain:
 	cd ./toolchain && ./build.sh
 .PHONY: toolchain
 
+qemu:
+	cd ./qemu && ./build.sh
+.PHONY: qemu
+
+requirements: toolchain qemu
+
 libc:
 	$(MAKE) -C user/libc
 

config.mk

@@ -3,9 +3,7 @@ TOOLCHAIN_DIR=toolchain
 BARE_METAL_TUPLE=arm-none-eabi
 BARE_METAL_TARGET:=$(BARE_METAL_TUPLE)
 
-QEMU=qemu-system-arm
-
-UBOOT_VERSION=2014.10
+QEMU=./qemu/qemu/bin/qemu-system-arm
 
 #CFLAGS = -mcpu=arm1136j-s
 CFLAGS = -mcpu=arm1176jz-s

kernel/Makefile

@@ -8,7 +8,7 @@ CFLAGS += -pipe -std=gnu99 -ffreestanding -Wall -Werror -g -O0 -mcpu=arm1176jzf-
 #PI_CFLAGS = -mfpu=vfp -march=armv6zk -mtune=arm1176jzf-s -nostartfiles
 
 # variables to define in the preprocessor.
-MEMORY = 128M
+MEMORY = 1G
 DEFINITIONS = MEM_DEBUG
 test: DEFINITIONS += ENABLE_TESTS # if we execute the test: rule, enable tests before recompiling
 KERNEL_PARAMS = root=/dev/ram mem=$(MEMORY)
@@ -25,8 +25,8 @@ CC:=$(TOOLCHAIN_PATH)/$(BARE_METAL_TUPLE)-gcc
 AS:=$(TOOLCHAIN_PATH)/$(BARE_METAL_TUPLE)-as
 LD:=$(TOOLCHAIN_PATH)/$(BARE_METAL_TUPLE)-gcc
 OBJCOPY:=$(TOOLCHAIN_PATH)/$(BARE_METAL_TUPLE)-objcopy
-MKIMAGE:=$(CURDIR)/../u-boot/u-boot-$(UBOOT_VERSION)/tools/mkimage
 GDB:=$(TOOLCHAIN_PATH)/$(BARE_METAL_TUPLE)-gdb
+QEMU := $(CURDIR)/../${QEMU}
 
 DIRS = $(shell find $(SOURCEDIR)/ -type d -print)
 C_SOURCE_FILES := $(foreach dir,$(DIRS),$(wildcard $(dir)/*.c)) $(TEST_MAIN_FILE)
@@ -57,8 +57,18 @@ run: build | builddir
 	#${QEMU} -M versatilepb -cpu arm1176 -sd $(BUILDDIR)/card.sd -m $(MEMORY) -nographic -semihosting -monitor none -serial stdio -kernel build/flash.bin -append "-load 0x410000 0x14000"
 	${QEMU} -kernel $(BUILDDIR)/kernel.elf -m $(MEMORY) -serial stdio -monitor none -M raspi2 -cpu arm1176 -nographic -append "-load 0x410000 0x14000" -semihosting
 
+debug: build | builddir
+		${QEMU} -kernel $(BUILDDIR)/kernel.elf -m $(MEMORY) -serial stdio -monitor none -M  raspi2 -cpu arm1176 -nographic -append "-load 0x410000 0x14000" -semihosting -S -s
+
+start_debug: build | builddir
+	$(GDB) -ex "target remote localhost:1234" -ex "symbol-file $(BUILDDIR)/kernel.sym"
+
 $(BUILDDIR)/kernel.elf: $(OBJECT_FILES) | builddir
 	$(LD) -T linker/kernel.ld -nostartfiles -Wl,-Map,kernel.map $^ -o $@
+	$(OBJCOPY) --only-keep-debug $(BUILDDIR)/kernel.elf $(BUILDDIR)/kernel.sym
+	$(OBJCOPY) --strip-debug $(BUILDDIR)/kernel.elf
+
+
 
 # Begin Pi Make
 $(BUILDDIR)/kernelPi.elf: $(C_OBJECT_FILES) | builddir

kernel/linker/kernel.ld

@@ -1,15 +1,37 @@
 ENTRY(_Reset)
+
+__KERNEL_VIRTUAL_OFFSET = 0x80000000;
+__BOOT_ADDRESS = 0x8000;
+
 SECTIONS
 {
-    . = 0x8000;
-    P_KERNBASE = .;
-    .startup . : { build/common/startup.o(.text) }
-    .text : { *(.text) }
-    .data : { *(.data) }
-    .bss : { *(.bss COMMON) }
-    P_KERNTOP = .;
-    . = ALIGN(8);
-    . = . + 0x1000;
-    stack_top = .;
-}
+    . = __BOOT_ADDRESS;
+    __BOOT_START = .;
+    .boot : {
+        */startup.o (.text)
+        */startup.o (.data)
+        */stacks.o (.text)
+        */startup.o (.bss)
+    }
+    __BOOT_END = .;
+    . += __KERNEL_VIRTUAL_OFFSET;
+
+    __KERNEL_BASE = .;
+    .text : AT(ADDR(.text) - __KERNEL_VIRTUAL_OFFSET) {
+        *(EXCLUDE_FILE (*/boot.o */stacks.o) .text)
+        *(.rodata*)
+    }
 
+    .data : AT(ADDR(.data) - __KERNEL_VIRTUAL_OFFSET){
+        *(EXCLUDE_FILE (*/boot.o */stacks.o) .data)
+     }
+
+    .bss : AT(ADDR(.bss) - __KERNEL_VIRTUAL_OFFSET) {
+        *(EXCLUDE_FILE (*/boot.o */stacks.o) COMMON)
+        *(EXCLUDE_FILE (*/boot.o) .bss)
+    }
+
+    /*make kernel top megabyte aligned*/
+    . = ALIGN(1024 * 1024);
+    __KERNEL_TOP = .;
+}