chore: ld

src/boot.s

@@ -0,0 +1,60 @@
+.syntax unified
+.cpu cortex-m4
+
+.section .text
+.global _init
+_init:
+    ldr r0, =0x1003E000
+    mov sp, r0
+
+    ldr r0, =_vector_table
+    ldr r1, =0xE000ED08
+    str r0, [r1]
+
+    push.w {r2-r9,r11,lr}
+    bl main
+    pop.w {r2-r9,r11,lr}
+1:  b 1b
+
+.section .vectors
+_vector_table:
+    .word _stack_top
+    .word _init
+    .word NMI_Handler
+    .word HardFault_Handler
+    .word MemManage_Handler
+    .word BusFault_Handler
+    .word UsageFault_Handler
+    .word 0                    /* Reserved */
+    .word 0                    /* Reserved */
+    .word 0                    /* Reserved */
+    .word 0                    /* Reserved */
+    .word SVC_Handler
+    .word DebugMon_Handler
+    .word 0                    /* Reserved */
+    .word PendSV_Handler
+    .word SysTick_Handler
+
+/* default */
+.weak NMI_Handler
+.weak HardFault_Handler
+.weak MemManage_Handler
+.weak BusFault_Handler
+.weak UsageFault_Handler
+.weak SVC_Handler
+.weak DebugMon_Handler
+.weak PendSV_Handler
+.weak SysTick_Handler
+
+.thumb_set NMI_Handler, Default_Handler
+.thumb_set HardFault_Handler, Default_Handler
+.thumb_set MemManage_Handler, Default_Handler
+.thumb_set BusFault_Handler, Default_Handler
+.thumb_set UsageFault_Handler, Default_Handler
+.thumb_set SVC_Handler, Default_Handler
+.thumb_set DebugMon_Handler, Default_Handler
+.thumb_set PendSV_Handler, Default_Handler
+.thumb_set SysTick_Handler, Default_Handler
+
+Default_Handler:
+    b Default_Handler