From 096971203495ea7b5b9f2e6ec4efe1241f1919a6 Mon Sep 17 00:00:00 2001 From: Wojtek Kosior Date: Tue, 22 Oct 2019 17:50:28 +0200 Subject: add processor mode changing --- kernel.c | 69 ++++++++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 45 insertions(+), 24 deletions(-) (limited to 'kernel.c') diff --git a/kernel.c b/kernel.c index c5918a1..a8df084 100644 --- a/kernel.c +++ b/kernel.c @@ -1,4 +1,5 @@ -#include +#include "uart.h" +#include "cpsr.h" void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) { @@ -22,15 +23,16 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) char *paging; - switch(ID_MMFR0 & 0xf) /* lowest 4 bits indicate VMSA support */ { - case 0 : paging = "no paging\n\r"; break; - case 1 : paging = "implementation defined paging\n\r"; break; - case 2 : paging = "VMSAv6, with cache and TLB type registers\n\r"; break; - case 3 : paging = "VMSAv7, with support for remapping and access flag\n\r"; break; - case 4 : paging = "VMSAv7 with PXN bit supported\n\r"; break; - case 5 : paging = "VMSAv7, PXN and long format descriptors. EPAE is supported.\n\r"; break; - default : paging = "?_? unknown paging ?_?\n\r"; - } + switch(ID_MMFR0 & 0xf) /* lowest 4 bits indicate VMSA support */ + { + case 0 : paging = "no paging\n\r"; break; + case 1 : paging = "implementation defined paging\n\r"; break; + case 2 : paging = "VMSAv6, with cache and TLB type registers\n\r"; break; + case 3 : paging = "VMSAv7, with support for remapping and access flag\n\r"; break; + case 4 : paging = "VMSAv7 with PXN bit supported\n\r"; break; + case 5 : paging = "VMSAv7, PXN and long format descriptors. EPAE is supported.\n\r"; break; + default : paging = "?_? unknown paging ?_?\n\r"; + } uart_puts(paging); @@ -38,24 +40,43 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) // get content of current program status register to check the current // processor mode asm("mrs %0, cpsr" : "=r" (CPSR) :: "memory"); - + char *mode; - switch(CPSR & 0x1f) /* lowest 5 bits indicate processor mode */ { - case 0x10 : mode = "User (PL0)"; break; - case 0x11 : mode = "FIQ (PL1)"; break; - case 0x12 : mode = "IRQ (PL1)"; break; - case 0x13 : mode = "Supervisor (PL1)"; break; - case 0x16 : mode = "Monitor (PL1)"; break; - case 0x17 : mode = "Abort (PL1)"; break; - case 0x1a : mode = "Hyp (PL2)"; break; - case 0x1b : mode = "Undefined (PL1)"; break; - case 0x1f : mode = "System (PL1)"; break; - default : mode = "Unknown mode"; break; - } + switch(read_processor_mode()) + { + case 0x10 : mode = "User (PL0)\r\n"; break; + case 0x11 : mode = "FIQ (PL1)\r\n"; break; + case 0x12 : mode = "IRQ (PL1)\r\n"; break; + case 0x13 : mode = "Supervisor (PL1)\r\n"; break; + case 0x16 : mode = "Monitor (PL1)\r\n"; break; + case 0x17 : mode = "Abort (PL1)\r\n"; break; + case 0x1a : mode = "Hyp (PL2)\r\n"; break; + case 0x1b : mode = "Undefined (PL1)\r\n"; break; + case 0x1f : mode = "System (PL1)\r\n"; break; + default : mode = "Unknown mode\r\n"; break; + } uart_puts(mode); - + + set_system_mode(); + + switch(read_processor_mode()) + { + case 0x10 : mode = "User (PL0)\r\n"; break; + case 0x11 : mode = "FIQ (PL1)\r\n"; break; + case 0x12 : mode = "IRQ (PL1)\r\n"; break; + case 0x13 : mode = "Supervisor (PL1)\r\n"; break; + case 0x16 : mode = "Monitor (PL1)\r\n"; break; + case 0x17 : mode = "Abort (PL1)\r\n"; break; + case 0x1a : mode = "Hyp (PL2)\r\n"; break; + case 0x1b : mode = "Undefined (PL1)\r\n"; break; + case 0x1f : mode = "System (PL1)\r\n"; break; + default : mode = "Unknown mode\r\n"; break; + } + + uart_puts(mode); + while (1) uart_putc(uart_getc()); } -- cgit v1.2.3