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authorvetch <vetch97@gmail.com>2020-01-04 19:37:32 +0100
committervetch <vetch97@gmail.com>2020-01-04 19:37:32 +0100
commit615e3302c9dd358bb64cd56d1f3814ad8d5df84d (patch)
tree07b0469807eb3bff7ff7d3f3576858642bc66675 /src/demo
parent885a097da42317f48cead2d91c0e0240066943a8 (diff)
downloadrpi-MMU-example-615e3302c9dd358bb64cd56d1f3814ad8d5df84d.tar.gz
rpi-MMU-example-615e3302c9dd358bb64cd56d1f3814ad8d5df84d.zip
rearranged files, updated makefile
Diffstat (limited to 'src/demo')
-rw-r--r--src/demo/demo_functionality.c121
-rw-r--r--src/demo/demo_functionality.h16
2 files changed, 137 insertions, 0 deletions
diff --git a/src/demo/demo_functionality.c b/src/demo/demo_functionality.c
new file mode 100644
index 0000000..14e37f2
--- /dev/null
+++ b/src/demo/demo_functionality.c
@@ -0,0 +1,121 @@
+#include "utils/io.h"
+#include "psr.h"
+#include "memory.h"
+#include "translation_table_descriptors.h"
+#include "ramfs.h"
+#include "utils/strings.h"
+#include "paging.h"
+#include "armclock.h"
+#include "scheduler.h"
+
+void demo_paging_support(void)
+{
+ uint32_t ID_MMFR0;
+ // get contents of coprocessor register to check for paging support
+ asm("mrc p15, 0, %0, c0, c1, 4" : "=r" (ID_MMFR0));
+
+ char *paging;
+
+ switch(ID_MMFR0 & 0xf) /* lowest 4 bits indicate VMSA support */
+ {
+ case 0 : paging = "no paging"; break;
+ case 1 : paging = "implementation defined paging"; break;
+ case 2 : paging = "VMSAv6, with cache and TLB type registers"; break;
+ case 3 : paging = "VMSAv7, with support for remapping and access flag"; break;
+ case 4 : paging = "VMSAv7 with PXN bit supported"; break;
+ case 5 : paging = "VMSAv7, PXN and long format descriptors. EPAE is supported."; break;
+ default : paging = "?_? unknown paging ?_?";
+ }
+
+ puts(paging);
+}
+
+void demo_current_mode(void)
+{
+
+ // get content of current program status register to check the current
+ // processor mode (should be system, as we set it in boot.S)
+ PSR_t CPSR = read_CPSR();
+
+ char *mode_name;
+
+ switch(CPSR.fields.PSR_MODE_4_0)
+ {
+ case MODE_USER : mode_name = "User (PL0)"; break;
+ case MODE_FIQ : mode_name = "FIQ (PL1)"; break;
+ case MODE_IRQ : mode_name = "IRQ (PL1)"; break;
+ case MODE_SUPERVISOR : mode_name = "Supervisor (PL1)"; break;
+ case MODE_MONITOR : mode_name = "Monitor (PL1)"; break;
+ case MODE_ABORT : mode_name = "Abort (PL1)"; break;
+ case MODE_HYPERVISOR : mode_name = "Hyp (PL2)"; break;
+ case MODE_UNDEFINED : mode_name = "Undefined (PL1)"; break;
+ case MODE_SYSTEM : mode_name = "System (PL1)"; break;
+ default : mode_name = "Unknown mode"; break;
+ }
+
+ prints("current mode: ");
+ puts(mode_name);
+}
+
+#define TRANSLATION_TABLE \
+ ((short_section_descriptor_t volatile*) TRANSLATION_TABLE_BASE)
+
+extern char
+ _binary_ramfs_img_start,
+ _binary_ramfs_img_end,
+ _binary_ramfs_img_size;
+
+void __attribute__((noreturn)) demo_setup_PL0(void)
+{
+ // find PL_0_test.img im ramfs
+ struct ramfile PL_0_test_img;
+
+ if (find_file(&_binary_ramfs_img_start, "PL_0_test.img",
+ &PL_0_test_img))
+ {
+ puts("PL_0_test.img not found :(");
+ asm volatile ("wfi");
+ }
+
+ // dummy value 5 for now, as we haven't implemented processes yet
+ uint16_t physical_section_number = claim_and_map_section
+ ((void*) 5, PL0_SECTION_NUMBER, AP_2_0_MODEL_RW_ALL);
+
+ if (physical_section_number == SECTION_NULL)
+ {
+ puts("Couldn't claim memory section for unprivileged code :(");
+ while(1);
+ }
+
+ size_t physical_section_start =
+ (((size_t) physical_section_number) << 20);
+
+ // check that translation works... by copying a string using one
+ // mapping and reading it using other :D
+ char str_part1[] = "mapped section for PL0 code (0x";
+ char str_part2[] = " -> 0x";
+ char str_part3[] = ")";
+
+ char *string_end = (char*) physical_section_start;
+
+ memcpy(string_end, str_part1, sizeof(str_part1) - 1);
+ uint32_to_hex(VIRTUAL_PL0_MEMORY_START,
+ string_end += sizeof(str_part1) - 1);
+ memcpy(string_end += 8, str_part2, sizeof(str_part2) - 1);
+ uint32_to_hex(physical_section_start,
+ string_end += sizeof(str_part2) - 1);
+ memcpy(string_end += 8, str_part3, sizeof(str_part3));
+
+ puts((char*) VIRTUAL_PL0_MEMORY_START);
+
+ // now paste a userspace program to that section
+ memcpy((void*) VIRTUAL_PL0_MEMORY_START,
+ PL_0_test_img.file_contents, PL_0_test_img.file_size);
+
+ puts("copied PL0 code to it's section");
+
+ puts("All ready! scheduling!");
+
+ schedule_new(VIRTUAL_PL0_MEMORY_START, // the new pc
+ VIRTUAL_PL0_MEMORY_END); // the new sp
+}
diff --git a/src/demo/demo_functionality.h b/src/demo/demo_functionality.h
new file mode 100644
index 0000000..a338c71
--- /dev/null
+++ b/src/demo/demo_functionality.h
@@ -0,0 +1,16 @@
+#ifndef DEMO_FUNCTIONALITY_H
+#define DEMO_FUNCTIONALITY_H
+
+void demo_paging_support(void);
+
+void demo_current_mode(void);
+
+//void demo_setup_libkernel(void);
+
+void demo_setup_PL0(void);
+
+//void demo_go_unprivileged(void);
+
+//void demo_setup_interrupts(void);
+
+#endif // DEMO_FUNCTIONALITY_H