Rpi

.github/workflows/build.yml

@@ -18,21 +18,21 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - name: MacOS (Arm64)
-            os: macos
-            os-version: 15
-            toolchain_arch: darwin-arm64
+          - name: Linux (x64)
+            os: ubuntu
+            os-version: 22.04
+            toolchain_arch: x86_64
 
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: '0'
 
-      - name: Install MacOS Dependencies
-        if: matrix.config.os == 'macos'
+      - name: Install Linux Dependencies
+        if: matrix.config.os == 'ubuntu'
         run: |
-          brew update
-          brew install make
+          sudo apt-get update
+          sudo apt-get install -y qemu-system-aarch64 qemu-utils make mtools dosfstools wget xz-utils
 
       - name: Install Toolchain
         run: |
@@ -44,7 +44,7 @@ jobs:
       - name: Build
         run: |
           mkdir -pv fs/redos/user
-          make all
+          make all LOAD_ADDR=0x41000000
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v4
@@ -54,7 +54,7 @@ jobs:
             kernel.elf
             kernel.img
             disk.img
-            run
+            run_virt
             debug
             createfs
-            fs/redos/user/*.elf
+            fs/redos/user/*.elf

.gitignore

@@ -7,3 +7,4 @@
 libshared.a
 *.a
 dump.dtb
+fs

Makefile

@@ -1,4 +1,6 @@
-.PHONY: all kernel user shared clean
+MODE ?= virt
+
+.PHONY: all kernel user shared clean raspi virt run debug
 
 all: shared user kernel
 	@echo "Build complete."
@@ -11,15 +13,23 @@ user:
 	$(MAKE) -C user
 
 kernel:
-	$(MAKE) -C kernel
+	$(MAKE) -C kernel LOAD_ADDR=$(LOAD_ADDR)
 
 clean:
 	$(MAKE) -C shared clean
 	$(MAKE) -C kernel clean
 	$(MAKE) -C user clean
 
-run: all
-	./run
+raspi:
+	$(MAKE) LOAD_ADDR=0x80000 all
+
+virt:
+	$(MAKE) LOAD_ADDR=0x41000000 all
+
+debug:
+	$(MAKE) $(MODE)
+	./rundebug MODE=$(MODE) $(ARGS)
 
-debug: all
-	./rundebug
+run: 
+	$(MAKE) $(MODE)
+	./run_$(MODE)

createfs

@@ -1,62 +1,45 @@
 #!/bin/bash
 
-IMG="disk.img"
 FOLDER="fs"
-SIZE_MB=64
-VOLUME_NAME="REDOS"
+VOLUME_LABEL="REDACTED OS"
+IMAGE=disk.img
 
-[ -f "$IMG" ] && rm "$IMG"
-[ -f "$IMG.dmg" ] && rm "$IMG.dmg"
-
-function need_executable() {
+if ! command -v "mcopy" >/dev/null 2>&1; then
+    echo "Error: this script depends on mtools. Please install it" >&2
+    exit 1
+fi
 
-    EXECUTABLE="$1"
+if ! command -v "mkfs.fat" >/dev/null 2>&1; then
+    echo "Error: this script depends on dosfstools. Please install it" >&2
+    exit 1
+fi
 
-    RECOMMENDED_PACKAGE="$2"
 
-    if ! command -v "$EXECUTABLE" >/dev/null 2>&1; then
-        echo "Error: this script needs the '$EXECUTABLE' executable, please install it" >&2
-        if [ -n "$RECOMMENDED_PACKAGE" ]; then
-            echo "The recommended package to install for this program is: '$RECOMMENDED_PACKAGE'" >&2
-        fi
-        exit 1
-    fi
+if [[ "$OSTYPE" == "darwin"* ]]; then
+  SIZE_KB=$(du -sk "$FOLDER" | cut -f1)
+else
+  SIZE_KB=$(du -s -B1 "$FOLDER" | awk '{print int($1/1024)}')
+fi
 
+power_of_two() {
+    local n=$1
+    local p=1
+    while (( p < n )); do
+        (( p *= 2 ))
+    done
+    echo $p
 }
 
-OS_TYPE="$(uname)"
-
-if [[ "$OS_TYPE" == "Darwin" ]]; then
-    echo "Running on macOS"
-    need_executable hdiutil
+SIZE_MB=$(( (SIZE_KB * 12 / 10 + 1023) / 1024 ))
 
-    DEV_INFO=$(hdiutil create -size ${SIZE_MB}m -fs "ExFAT" -layout NONE -volname "$VOLUME_NAME" "$IMG" -attach)
-    MOUNTPOINT=$(echo "$DEV_INFO" | awk '/\/Volumes\// {print $NF}')
-    DEVICE=$(echo "$DEV_INFO" | awk '/\/dev\/disk/ {print $1; exit}')
+SIZE_MB=$(power_of_two "$SIZE_MB")
 
-    cp -R "$FOLDER/" "$MOUNTPOINT/"
-
-    #.fseventsd is not getting deleted i think
-    find "$MOUNTPOINT/" -type f \( -name '.DS_Store' -o -name '.fseventsd' -o -name '._*' \) -delete
-
-    echo "$MOUNTPOINT"
-    echo "DEV: $DEVICE"
-
-    hdiutil detach "$DEVICE"
-    mv "$IMG.dmg" "$IMG"
-
-elif [[ "$OS_TYPE" == "Linux" ]]; then
-    echo "Running on Linux"
+if ((SIZE_MB < 64)); then
+    SIZE_MB=64
+fi
 
-    need_executable dd
-    need_executable mkfs.exfat "exfatprogs"
+dd if=/dev/zero of=$IMAGE bs=1M count=$SIZE_MB
 
-    # 1. Create an empty image file
-    dd if=/dev/zero of="$IMG" bs=1M count="$SIZE_MB"
+mkfs.fat -F 32 -n "$VOLUME_LABEL" $IMAGE
 
-    # 2. Format it as ExFAT
-    mkfs.exfat -n "$VOLUME_NAME" "$IMG"
-else
-    echo "Unknown OS: $OS_TYPE" >&2
-    exit 1
-fi
+mcopy -i $IMAGE -s "$FOLDER"/* ::

kernel/Makefile

@@ -4,7 +4,8 @@ LD = $(ARCH)-ld
 OBJCOPY = $(ARCH)-objcopy
 
 CFLAGS = -g -O0 -std=c17 -nostdlib -ffreestanding -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Wall -Wextra -mcpu=cortex-a72 -I. -I../shared -I../user
-LDFLAGS = -T $(shell ls *.ld)
+
+LDFLAGS = -T $(shell ls *.ld) --defsym=LOAD_ADDR=$(LOAD_ADDR)
 
 C_SRC = $(shell find . -name '*.c')
 ASM_SRC = $(shell find . -name '*.S')

kernel/async.c

@@ -0,0 +1,31 @@
+#include "async.h"
+#include "console/kio.h"
+
+void delay(uint32_t ms) {
+    uint64_t freq;
+    asm volatile ("mrs %0, cntfrq_el0" : "=r"(freq));
+
+    uint64_t ticks;
+    asm volatile ("mrs %0, cntpct_el0" : "=r"(ticks));
+
+    uint64_t target = ticks + (freq / 1000) * ms;
+
+    while (1) {
+        uint64_t now;
+        asm volatile ("mrs %0, cntpct_el0" : "=r"(now));
+        if (now >= target) break;
+    }
+}
+
+bool wait(uint32_t *reg, uint32_t expected_value, bool match, uint32_t timeout){
+    bool condition;
+    do {
+        delay(1);
+        timeout--;
+        if (timeout == 0)
+            return false;
+        condition = (*reg & expected_value) == expected_value;
+    } while ((match > 0) ^ condition);
+
+    return true;
+}

kernel/async.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+void delay(uint32_t count);
+bool wait(uint32_t *reg, uint32_t expected_value, bool match, uint32_t timeout);
+#ifdef __cplusplus
+}
+#endif

kernel/boot.S

@@ -1,11 +1,115 @@
 .global _start
+.section .text
 _start:
+    mrs x0, mpidr_el1
+    and x0, x0, #3
+    cbz x0, setup_vars
+half:
+    wfe
+    b half
+
+setup_vars:
+    ldr     x5, =__bss_start
+    ldr     x6, =__bss_end
+clear_bss:
+    cmp     x5, x6
+    b.ge    check_hw
+    str     xzr, [x5], #8
+    b       clear_bss
+
+check_hw:
+    adr     x0, . 
+
+    movz    x1, #0x4100, lsl #16
+    and     x2, x0, #0xFFF00000
+    cmp     x2, x1
+    b.eq    virt
+
+    movz    x1, #0x4000, lsl #16
+    and     x2, x0, #0xFFF00000
+    cmp     x2, x1
+    b.eq    virt
+
+    mov     x1, #0x80000
+    and     x2, x0, #0xFFFFF000
+    cmp     x2, x1
+    b.eq    rpi
+
+    mov     x1, #0x100000
+    and     x2, x0, #0xFFFFF000
+    cmp     x2, x1
+    b.eq    rpi
+
+    b       .//Halt if none
+
+virt:
+    mov     w0, #1
+    adrp    x1, BOARD_TYPE
+    strb    w0, [x1, #:lo12:BOARD_TYPE]
+    b       stack_setup
+rpi:
+    mov     w0, #2
+    adrp    x1, BOARD_TYPE
+    strb    w0, [x1, #:lo12:BOARD_TYPE]
+    b       drop_el3
+
+drop_el3:
+    mrs x0, CurrentEL
+    lsr x0, x0, #2
+    cmp x0, #3
+    b.ne el2_entry
+
+    msr sctlr_el2, xzr
+    mrs x0, hcr_el2
+    orr x0, x0, #(1<<19)
+    msr hcr_el2, x0
+
+    mrs x0, scr_el3
+    orr x0, x0, #(1<<10)
+    orr x0, x0, #(1<<0)
+    msr scr_el3, x0
+
+    mov x0, #0b01001//DAIF 0000
+    msr spsr_el3, x0
+
+    adr x0, el2_entry
+    msr elr_el3, x0
+    eret
+
+el2_entry:
+    mrs x0, CurrentEL
+    lsr x0, x0, #2
+    cmp x0, #2
+    b.ne el1_non_secure
+
+    mov	x0, #3 << 20
+    msr	cpacr_el1, x0
+
+    ldr x0, =0x30C00800
+    msr	sctlr_el1, x0
+
+    mrs x0, hcr_el2
+    orr x0, x0, #(1<<31)
+    msr hcr_el2, x0
+
+    mov x0, 0x1C5
+    msr spsr_el2, x0
+
+    adr x0, el1_non_secure
+    msr elr_el2, x0
+
+    eret
+
+el1_non_secure:
+stack_setup:
     ldr x1, =stack_top
     mov sp, x1
+
     mov x29, xzr
     mov x30, xzr
-    mrs x0, CPACR_EL1
-    orr x0, x0, #(3 << 20)
-    msr CPACR_EL1, x0
+    mrs x1, CPACR_EL1
+    orr x1, x1, #(3 << 20)
+    msr CPACR_EL1, x1
     bl kernel_main
+
     b .

kernel/console/kconsole/kconsole.cpp

@@ -22,7 +22,6 @@ bool KernelConsole::check_ready(){
 
 void KernelConsole::resize() {
     gpu_size screen = gpu_get_screen_size();
-    uart_puthex(screen.width);
     columns = screen.width / char_width;
     rows = screen.height / char_height;
 

kernel/console/serial/uart.c

@@ -1,6 +1,8 @@
 #include "console/serial/uart.h"
 #include "memory/memory_access.h"
 #include "exceptions/irq.h"
+#include "gpio.h"
+#include "hw/hw.h"
 
 #define UART0_DR   (UART0_BASE + 0x00)
 #define UART0_FR   (UART0_BASE + 0x18)
@@ -16,6 +18,11 @@ uint64_t get_uart_base(){
 void enable_uart() {
     write32(UART0_CR, 0x0);
 
+    if (BOARD_TYPE == 2){
+        enable_gpio_pin(14);
+        enable_gpio_pin(15);
+    }
+
     write32(UART0_IBRD, 1);
     write32(UART0_FBRD, 40);