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| author | Jason Thorpe <thorpej@me.com> | 2021-06-02 20:53:17 -0700 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2021-06-06 13:26:29 -0700 |
| commit | 5e915346477f4f2f33345c7dbe711be828b58730 (patch) | |
| tree | 4b7eea9639a68b7a5dddf8272ffb3a8b582d8303 /pal.S | |
| parent | b5bee8227775b91e12c0b6635977d44f2d7fa376 (diff) | |
| download | qemu-palcode-5e915346477f4f2f33345c7dbe711be828b58730.zip qemu-palcode-5e915346477f4f2f33345c7dbe711be828b58730.tar.gz qemu-palcode-5e915346477f4f2f33345c7dbe711be828b58730.tar.bz2 | |
Fixes for secondary CPU start-up.
Changes to make secondary CPU start-up work on NetBSD, which depends
on some specific behavior in the architecture specification:
- Change the internal swppal() function to take the new VPTPTR and
Procedure Value as explicit arguments. Adapt do_start() to the
new the new swppal() signature.
- In do_start_wait(), extract the new VPTPTR and PV from the relevant
HWRPB fields, which will have been initialized by the OS, and pass
them to swppal().
- In the SWPPAL PAL call, get the value to stuff into PV (r27) from
a4 (r20), and add a comment describing why this implementation detail
is allowed by the architecture specification.
Signed-off-by: Jason Thorpe <thorpej@me.com>
Message-Id: <20210603035317.6814-9-thorpej@me.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'pal.S')
| -rw-r--r-- | pal.S | 13 |
1 files changed, 9 insertions, 4 deletions
@@ -566,6 +566,8 @@ ENDFN CallPal_Cserve_Cont * r17 (a1) = New PC * r18 (a2) = New PCB * r19 (a3) = New VptPtr + * r20 (a4) = New Procedure Value (to place into $27) + * (Non-standard; See note below.) * * OUTPUT PARAMETERS: * @@ -574,11 +576,14 @@ ENDFN CallPal_Cserve_Cont * 1 - Unknown PALcode variant * 2 - Known PALcode variant, but PALcode not loaded * - * r26 (ra) = r27 (pv) = New PC + * r26 (ra) = New PC + * r27 (pv) = From r20 * Note that this is non-architected, but is relied on by * the usage of SwpPal within our own console code in order - * to simplify its use within C code. - * + * to simplify its use within C code. We can get away with + * the extra non-standard argument (in $20) because as + * architected, all registers except SP and R0 are + * UNPREDICTABLE; therefore private internal usage is fine. */ ORG_CALL_PAL_PRIV(0x0A) CallPal_SwpPal: @@ -624,7 +629,7 @@ CallPal_SwpPal_Cont: mtpr $31, qemu_tbia // Flush TLB for new PTBR mov a1, $26 - mov a1, $27 + mov a4, $27 hw_ret (a1) ENDFN CallPal_SwpPal_Cont .previous |