diff options
Diffstat (limited to 'kernel/start.c')
| -rw-r--r-- | kernel/start.c | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/kernel/start.c b/kernel/start.c index b7170ae..859ae5d 100644 --- a/kernel/start.c +++ b/kernel/start.c @@ -3,6 +3,7 @@ #include "kernel/kalloc.h"
#include "kernel/vm.h"
#include "kernel/cpu.h"
+#include "kernel/aplic.h"
Cpu cpus[MAX_CPU];
@@ -12,13 +13,51 @@ extern uint32_t _ram_end; void kstrap()
{
- panic("kstrap");
+ uint32_t scause;
+ __asm__ volatile("csrr %0, scause" : "=r"(scause));
+ switch (scause)
+ {
+ case 0: panic("kstrap: Instruction address misaligned");
+ case 1: panic("kstrap: Instruction access fault");
+ case 2: panic("kstrap: Illegal instruction");
+ case 3: panic("kstrap: Breakpoint");
+ case 4: panic("kstrap: Load address misaligned");
+ case 5: panic("kstrap: Load access fault");
+ case 6: panic("kstrap: Store/AMO address misaligned");
+ case 7: panic("kstrap: Store/AMO access fault");
+ case 8: panic("kstrap: Environment call from U-mode");
+ case 9: panic("kstrap: Environment call from S-mode");
+ case 12: panic("kstrap: Instruction page fault");
+ case 13: panic("kstrap: Load page fault");
+ case 14: panic("kstrap: Reserved");
+ case 15: panic("kstrap: Store/AMO page fault");
+ case 18: panic("kstrap: Software check");
+ case 19: panic("kstrap: Hardware error");
+ default: panic("kstrap: Unknown");
+ }
+}
+
+void uart_init()
+{
+ volatile char* UART_BASE = (volatile char*)0x1000'0000;
+
+ // Set LCR[1:0] to 0b11 for 8-bit words
+ *(UART_BASE + 3) = 0b0000'0011;
+
+ // Set FCR[0] to 1 to enable FIFO
+ *(UART_BASE + 2) = 0b0000'0001;
+
+ // Set IER[0] to 1 to enable interrupts on receive
+ *(UART_BASE + 1) = 0b0000'0001;
}
void kstart()
{
+ uart_init();
+
kalloc_init();
kvm_init();
+ aplic_init();
panic("kstart: end");
}
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