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path: root/src/arch/riscv/include/vm.h
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2016-10-24RISCV: Clean up the common architectural codeRonald G. Minnich
This version of coreboot successfully starts a Harvey (Plan 9) kernel as a payload, entering main() with no supporting assembly code for startup. The Harvey port is not complete so it just panics but ... it gets started. We provide a standard payload function that takes a pointer argument and makes the jump from machine to supervisor mode; the days of kernels running in machine mode are over. We do some small tweaks to the virtual memory code. We temporarily disable two functions that won't work on some targets as register numbers changed between 1.7 and 1.9. Once lowrisc catches up we'll reenable them. We add the PAGETABLES to the memlayout.ld and use _pagetables in the virtual memory setup code. We now use the _stack and _estack from memlayout so we know where things are. As time goes on maybe we can kill all the magic numbers. Change-Id: I6caadfa9627fa35e31580492be01d4af908d31d9 Signed-off-by: Ronald G. Minnich <rminnich@gmail.com> Reviewed-on: https://review.coreboot.org/17058 Tested-by: build bot (Jenkins) Reviewed-by: Furquan Shaikh <furquan@google.com>
2016-08-23arch/riscv: Add functions to read/write memory on behalf of supervisor/user modeJonathan Neuschäfer
Normally machine-mode code operates completely within physical address space. When emulating less privileged memory accesses (e.g. when the hardware doesn't support unaligned read/write), it is useful to access memory through the MMU (and with virtual addresses); this patch implements this functionality using the MPRV bit. Change-Id: Ic3b3301f348769faf3ee3ef2a78935dfbcbd15fd Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-on: https://review.coreboot.org/16260 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2016-08-23arch/riscv: Print the page table structure after constructionJonathan Neuschäfer
A new Kconfig option, DEBUG_PRINT_PAGE_TABLES, is added to control this behaviour. It is currently only available on RISC-V, but other architectures can use it, too, should the need arise. Change-Id: I52a863d8bc814ab3ed3a1f141d0a77edc6e4044d Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-on: https://review.coreboot.org/16015 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth <martinroth@google.com>
2016-07-18arch/riscv: Remove enter_supervisorJonathan Neuschäfer
This function is unused since coreboot starts payloads in machine mode, and it uses the obsolete eret instruction. Change-Id: I98d7d0de5a3959821c21a0ba4319efb610fdefde Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-on: https://review.coreboot.org/15729 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2015-09-10riscv-virtual-memory: Add virtual memory setupThaminda Edirisooriya
Execution in supervisor level code in RISCV requires early setup of virtual memory. Add initialization calls in src/arch/riscv/virtual_memory.c to implement the required page table setup, and helper functions to use when jumping to the payload correctly in riscv. Change-Id: I46e080e0ee8dc13277d567dcd4bf0f61a4507b76 Signed-off-by: Thaminda Edirisooriya <thaminda@google.com> Reviewed-on: http://review.coreboot.org/11369 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>