diff options
Diffstat (limited to 'src/kernel/svc.c')
| -rw-r--r-- | src/kernel/svc.c | 35 |
1 files changed, 17 insertions, 18 deletions
diff --git a/src/kernel/svc.c b/src/kernel/svc.c index edf2b68..4aa156e 100644 --- a/src/kernel/svc.c +++ b/src/kernel/svc.c @@ -1,7 +1,6 @@ /** * @file svc.c * An unused handler for SVC calls - * TODO: use SVC calls, possibly allowing for switch to unprivileged mode? * * Copyright (C) 2018 Clyne Sullivan * @@ -28,9 +27,17 @@ extern void gpio_svc(uint32_t *); extern void clock_svc(uint32_t *); extern void task_svc(uint32_t *); -void svc_handler(uint32_t *args) -{ - /*uint32_t*/int svc_number = ((char *)args[6])[-2]; +void SVC_Handler(void) { + uint32_t *args; + + asm("\ + tst lr, #4; \ + ite eq; \ + mrseq %0, msp; \ + mrsne %0, psp; \ + " : "=r" (args)); + + int svc_number = ((char *)args[6])[-2]; switch (svc_number) { case -1: @@ -44,24 +51,16 @@ void svc_handler(uint32_t *args) clock_svc(args); break; case 3: + asm("\ + mrs r0, psp; \ + stmdb r0!, {r4-r11, r14}; \ + mov %0, r0; \ + " : "=r" (args[0])); task_svc(args); - asm("mov r0, %0" :: "r" (args[0])); + asm("mov r0, %0" :: "r" (args[0])); // TODO doesn't work, r0 overwritten on exc. return break; default: break; } } -void SVC_Handler(void) { - uint32_t *args; - - asm("\ - tst lr, #4; \ - ite eq; \ - mrseq %0, msp; \ - mrsne %0, psp; \ - " : "=r" (args)); - - svc_handler(args); -} - |