Difference between revisions of "Memory layout"
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| − | All executable pages are read-only, and data pages have the execute-never permission set. Normally .text from the loaded ExeFS:/.code is the only mapped executable memory. Executable [[RO Services|CROs]] can be loaded into memory, once loaded the CRO .text section memory page permissions are changed via [[SVC|ControlProcessMemory]] from RW- to R-X. | + | All executable pages are read-only, and data pages have the execute-never permission set. Normally .text from the loaded ExeFS:/.code is the only mapped executable memory. Executable [[RO Services|CROs]] can be loaded into memory, once loaded the CRO .text section memory page permissions are changed via [[SVC|ControlProcessMemory]] from RW- to R-X. The address and size of each ExeFS:/.code section is stored in the exheader, the permissions for each section is: .text R-X, .rodata R--, .data RW-, and .bss RW-. The loaded .code is mapped to the addresses specified in the exheader by the ARM11 kernel. |
Revision as of 17:41, 12 November 2012
Physical memory regions
| Address | Size | Description |
|---|---|---|
| 0x0 | 0x10000 | Bootrom (super secret code/data @ 0x8000) |
| 0x10000 | 0x10000 | Bootrom mirror |
| 0x10000000 | ? | IO memory |
| 0x1FF00000 | 0x80000 | DSP memory |
| 0x1FF80000 | 0x80000 | AXI WRAM |
| 0x20000000 | 0x8000000 | FCRAM |
ARM11 User-land memory regions
| Virtual Address | Region Max Size | Description |
|---|---|---|
| 0x00100000 / 0x14000000 | 0x03F00000 | The ExeFS:/.code is loaded here, executables must be loaded to the 0x00100000 region when the exheader "special memory" flag is clear. The 0x03F00000-byte size restriction only applies when this flag is clear. Executables are usually loaded to 0x14000000 when the exheader "special memory" flag is set, however this address can be arbitrary. |
| 0x08000000 | Heap mapped by ControlMemory | |
| 0x1EC00000 | IO registers, the mapped IO pages which each process can access is specified in the CXI exheader.(Applications normally don't have access to registers in this range) |
All executable pages are read-only, and data pages have the execute-never permission set. Normally .text from the loaded ExeFS:/.code is the only mapped executable memory. Executable CROs can be loaded into memory, once loaded the CRO .text section memory page permissions are changed via ControlProcessMemory from RW- to R-X. The address and size of each ExeFS:/.code section is stored in the exheader, the permissions for each section is: .text R-X, .rodata R--, .data RW-, and .bss RW-. The loaded .code is mapped to the addresses specified in the exheader by the ARM11 kernel.