Updated with polarity exercise

polarity_checker/.vscode/launch.json

@@ -0,0 +1,31 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {   "name": "Pico Debug",
+            "device": "RP2040",
+            "gdbPath": "${env:GDB_PATH}",
+            "cwd": "${workspaceRoot}",
+            "executable": "${command:cmake.launchTargetPath}",
+            "request": "launch",
+            "type": "cortex-debug",
+            "servertype": "openocd",
+            "configFiles": [
+                "interface/cmsis-dap.cfg",
+                "target/rp2040.cfg"
+            ],
+            "searchDir": [
+                "${env:OPENOCD_PATH}/tcl"
+            ],
+            "openOCDLaunchCommands": [
+                "adapter speed 5000"
+            ],
+            "runToEntryPoint": "main",
+            "svdFile": "${env:PICO_SDK_PATH}/src/rp2040/hardware_regs/rp2040.svd",
+            "postRestartCommands": [
+                "break main",
+                "continue"
+            ],
+            "showDevDebugOutput": "parsed"
+        }
+    ]
+}

polarity_checker/.vscode/settings.json

@@ -0,0 +1,23 @@
+{
+    // These settings tweaks to the cmake plugin will ensure
+    // that you debug using cortex-debug instead of trying to launch
+    // a Pico binary on the host
+    "cmake.statusbar.advanced": {
+        "debug": {
+            "visibility": "hidden"
+        },
+        "launch": {
+            "visibility": "hidden"
+        },
+        "build": {
+            "visibility": "hidden"
+        },
+        "buildTarget": {
+            "visibility": "hidden"
+        }
+    },
+    "cmake.buildBeforeRun": true,
+    "C_Cpp.default.configurationProvider": "ms-vscode.cmake-tools",
+    "cortex-debug.openocdPath": "${env:OPENOCD_PATH}/src/openocd",
+    "cortex-debug.variableUseNaturalFormat": true
+}

polarity_checker/CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.18)
+include($ENV{PICO_SDK_PATH}\\external\\pico_sdk_import.cmake)
+
+project(program C CXX ASM)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+
+include_directories(${CMAKE_SOURCE_DIR})
+
+add_executable(${PROJECT_NAME}
+    program.S
+)
+
+set(PICO_BOARD pico_w)
+
+pico_sdk_init()
+
+target_link_libraries(${PROJECT_NAME}
+    pico_stdlib
+)
+
+pico_add_extra_outputs(${PROJECT_NAME})
+
+pico_enable_stdio_usb(${PROJECT_NAME} 1)
+pico_enable_stdio_uart(${PROJECT_NAME} 1)

polarity_checker/program.S

@@ -0,0 +1,42 @@
+.thumb_func		    	@ Necessary because sdk uses BLX
+.global main	   	 	@ Provide program starting address
+
+main:
+	BL		stdio_init_all	@ initialize uart or usb
+    LDR     R0, =polarities
+    MOV     R3, #0          @ count of negative values
+    MOV     R4, #0          @ count of positive values
+    MOV     R5, #0          @ largest negative value
+    MOV     R6, #0          @ largest positive value
+    MOV     R7, #0
+
+polarity:
+@ TODO: Load the array size location
+@ TODO: Keep track of amount of numbers
+@ TODO: Compare the amount of numbers seen to size
+@ TODO: If numbers are equal, then we're done -- go to print
+@ TODO: If not, load the number from the array
+@ TODO: Find out if number is negative or non-negative
+@ TODO: Branch to correct handler
+
+@ TODO: Handle negative numbers
+@ TODO: Record max negative number
+@ TODO: Handle positive numbers
+@ TODO: Record max positive number
+@ TODO: Move to next entry
+
+@ TODO: Print results
+
+rest:
+    NOP 
+    B       rest
+
+.data
+    format_pos:     .asciz  "POSITIVES: %d; MAX: %d\n"
+    format_neg:     .asciz  "NEGATIVES: %d; MAX: %d\n"
+    polarities: .byte 10, 88, -30, 98, 83, 29, -85, 36, -26, 79, 39, -35
+                .byte 62, 40, 26, 33, -14, 12, -17, 64, -43, 57, 17, -88
+                .byte -18, 82, -34, -7, -72, -42, -96, -70, -62, -45, -25, 9
+                .byte 6, -48, -47, -100, -90, 44, -27, -65, 92, 1, -1, -49
+    end:  
+    .set    size,   end - polarities